taxonID	type	description	language	source
D27B87A3FF99F11DFC7EFA809254FD8F.taxon	description	(Figs. 2 a, 3 a-h, 20 a)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF99F11DFC7EFA809254FD8F.taxon	materials_examined	Material examined. TYPE: I. acula, Holotype ♂, CA: Fresno Co., 7 mi NE Academy, elev. 800 feet, Dry Cr., 19 / IV / 1955, D. L. Abell (CAS # 8591). Additional Specimens. CALIFORNIA: Amador Co., Big Indian Creek, 2 km S NF Cosumnes R., Hwy 49, 25 / IV / 1986, R. L. Bottorff, Larvae (NMNH); Big Indian Creek, Hwy 49, 2.9 mi N Plymouth, unnamed rd. xing, 25 / IV / 2009, J. Sandberg, Larvae; Little Indian Creek, 3 km W Plymouth, 25 / IV / 1986, R. L. Bottorff, Exuviae (NMNH); Little Indian Creek, 3 km W Plymouth, 12 / V / 1987, R. L. Bottorff, ♂ ♀ reared, Larvae (CAS); Little Indian Creek, 3 km W Plymouth, 12 / V / 1987, R. L. Bottorff, ♂ ♀ reared (NMNH). Butte Co.,?, 9 mi N Oroville, 24 / IV / 1955, S. W. Hitchcock, ♂, Larvae (NMNH); El Dorado Co., Cooper Canyon Creek, Rattlesnake Bar Rd. xing, 2.25 mi SE Hwy 49, 30 / III / 2009, J. Sandberg, Larvae; Deadman Creek, Church Mine Rd. xing, 2.45 mi SE El Dorado, 30 / III / 2009, J. Sandberg, Larvae; J. Sandberg, D. Pickard, 04 / IV / 2009, Larvae; 05 / IV / 2009, Larvae; 25 / IV / 2009, Larvae (reared); 10 / V / 2009, Larvae (reared); 16 / V / 2009, Larvae (reared); 23 / V / 2009, ♂ ♀, Larvae (reared); Martinez Creek, Martinez Cr. Rd., 3.5 mi SE El Dorado, 04 / IV / 2009, J. Sandberg, D. Pickard, Larvae; NF Cosumnes River, Hwy 49 cattle coral, 1.7 mi S Nashville, below confluence w / MF Cosumnes R., 28 / III / 2009, J. Sandberg, Larvae; Tributary of NF Cosumnes River, ~ 2 km W Martinez Cr., S El Dorado, 12 / V / 1987, R. L. Bottorff, 12 / V / 1987, ♂ ♀, Larvae (CAS); Tributary of NF Cosumnes River, Union Mine Rd., 3.4 mi (5.5 km) N Nashville at McNulty Mine Rd. xing, 25 / IV / 2009, J. Sandberg, Larvae (reared).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF99F11DFC7EFA809254FD8F.taxon	description	Male larva. Body length of mature larva 10 – 11 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus connected to light frontoclypeus area by median longitudinal light band, lateral thin arms directed posterolaterally, extending to antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area partially light and generally diamond shaped, completely enclosed by dark pigment, light area extending past posterior ocelli, reaching dark pigment below the arms of the epicranial suture; occiput with irregular spinulae band extending from below eye to near median epicranial suture, not enclosed completely by dark pigment (Fig. 3 a). Lacinia bidentate, total length 687 – 786 µm (Fig. 2 a, 3 e- h, Tables 2 - 4); submarginal row (A + B) with 4 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 3 h); 1 – 2 submarginal setae (A), the first inserted at base of apical tooth (AT) inner margin, the second when present, located between AT and SAT inner margins, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT or broken, and 1 dorsal seta (DS) located below SAT inner margin sometimes obstructed by SAT (Figs. 3 gh); 2 – 3 submarginal setae (B) located past SAT inner margin (Figs 3 g-h); 7 – 9 marginal setae (C) initially long-stout and widely spaced, last few shorter and closer, blending into and difficult to differentiate from dorsal surface setae (Fig. 3 e); 28 – 41 ventral surface setae (D) scattered below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length (Fig. 3 f); dorsal surface setae (DSS) continue from last marginal seta (C) as a single, laterally protruding, submarginal row along inner-lateral margin, ending before posteriormost ventral surface setae (Fig. 3 f). Galea with 42 – 61 setae in thick ventral band, apex with 4 – 5 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with median light area bordered (at least partially) by thin, irregular dark bands; discs each with partially to totally enclosed light areas or “ windows ” and fine dark clothing setae, lateral margins with broad light bands (Fig. 3 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 3 c). Legs with numerous fine dark clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated along dorsal surfaces; fine silky setae numerous and continuous on dorsal surfaces of femora and tibia (Fig. 20 a); tibia with faint transverse bands near proximal end. Abdominal terga with three distinct longitudinal dark stripes; wide light median longitudinal band bisected with thin dark median longitudinal stripe; lateral pair of dark longitudinal stripes about twice as wide as median dark stripe, not extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 3 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF99F11DFC7EFA809254FD8F.taxon	distribution	Distribution. California: Sierra Nevada foothills.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF99F11DFC7EFA809254FD8F.taxon	diagnosis	Diagnosis. Among the male larvae with 2 – 4 submarginal row (A + B) setae (Table 2), I. acula is most similar to I. bifurcata (Figs. 3 a-h, 6 a-h). Characters that distinguish this species from I. bifurcata include fine silky setae numerous and continuous on dorsal surfaces of femora and tibia (Fig. 20 a), and abdomen with median longitudinal thin dark pigment band (Fig. 3 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF99F11DFC7EFA809254FD8F.taxon	discussion	Remarks. Isoperla acula co-occurred with I. adunca, Isoperla miwok Bottorff & Szczytko, and I. marmorata in mostly non-perennial and one perennial central Sierra Nevada foothill streams. Emergence occurred in April – May (lasting to early June in wetter years) and life history studies are needed to determine how I. acula, I. adunca and I. miwok cope with shortened surface flow periods. It is suspected that larvae move to hyporheic zones when stream flow ceases in late summer.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9DF11FFEEEFD5A90BEFD8F.taxon	description	(Figs. 2 b, 4 a-h, 20 b)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9DF11FFEEEFD5A90BEFD8F.taxon	materials_examined	Material examined. TYPES: I. adunca, Holotype ♂, CA: Santa Clara Co., 5 mi E Mt. Hamilton, Isabel Creek?, 31 / V / 1949 (CAS # 8592). Paratype ♂, CA: Tuolumne Co., Keystone, 25 / IV / 1951, J. W. MacSwain (CAS). Paratype ♂ and ♀, same as Holotype, (CAS). Additional Specimens. CALIFORNIA: Alameda Co., Indian Creek, 1.8 mi (2.9 km) upstream of San Antonio Reservoir, 25 / V / 2010, Larva (ABL); Amador Co., Big Indian Creek, N Plymouth, 25 / IV / 1986, R. L. Bottorff, Larvae (NMNH); Big Indian Creek, N Plymouth, 9 / V / 1986, R. L. Bottorff, ♀, Larvae (NMNH); Big Indian Creek, N Plymouth, 30 / V / 1986, R. L. Bottorff, Larvae (NMNH); Big Indian Creek, Hwy 49, 2.9 mi (4.7 km) N Plymouth, 4 / IV / 2009, J. Sandberg, D. Pickard, Larvae; Big Indian Creek, Hwy 49, 2.9 mi (4.7 km) N Plymouth, 25 / IV / 2009, J. Sandberg, Larvae (reared); Little Indian Creek, 3 km W Plymouth, 25 / IV / 1986, R. L. Bottorff, ♂ (everted), Larvae (NMNH); Little Indian Creek, 3 km W Plymouth, 12 / V / 1987, R. L. Bottorff, ♂ ♀, Larvae (NMNH); Little Indian Creek, Old Sacramento Rd xing, 1.5 mi (2.4 km) W Plymouth, 4 / IV / 2009, J. Sandberg, D. Pickard, Larvae; Butte Co., Clear Creek, at Hwy 149, between Hwys 99 & 70, T 1 - 3, 4 / IV / 2004, Larvae (ABL); Dry Creek, at Hwy 149, between Hwys 99 & 70, T 1 - 2, 4 / IV / 2004, Larvae (ABL); Campbell Creek & tributary, North Table Mountain Wildlife Area, Cherokee Rd, 5 mi (8 km) S Cherokee, 3 / III / 2007, J. Sandberg, Larvae (reared); 7 / IV / 2007, Larvae (reared); 13 / IV / 2007, ♂ ♀, Larvae (reared); 18 / IV / 2007, Larvae; 23 / II / 2008, Larvae; 24 / III / 2008, Larvae; 30 / III / 2008, Larvae; 30 / IV / 2008, Larvae; 2 / V / 2010, J. Sandberg, A. Richards, Larvae (reared); Contra Costa Co., Mitchell Creek, 0.5 mi (0.8 km) below Uncle Sam Canyon, R 1, 22 / IV / 2009, Larvae (ABL); Mitchell Creek, 250 m upstream of bridge at Mt. Diablo State Park entrance, 24 / V / 2010, Larva (ABL); El Dorado Co., SF Cosumnes River, Site 22, R 2, 28 / V / 1995, Larvae (ABL); Deadman Creek, Church Mine Rd xing, 2.4 mi (3.9 km) SE El Dorado, 10 / V / 2009, 16 / V / 2009, 23 / V / 2009, J. Sandberg, ♂ ♀, Larvae (reared); Greenwood Creek, Greenwood Creek Park, Hwy 49, 4 mi (6 km) E Pilot Hill, 10 / V / 2009, J. Sandberg, Larvae; Fresno Co., Mill Creek, Rt 180, E Fresno, 1800 feet, 7 / VI / 1963, C. P. Alexander, ♂ ♀ (NMNH); Sacramento Co., Cosumnes River, at Michigan Bar, 6 / VII / 1982, R. L. Bottorff, Larvae (ABL); San Diego Co., Nobel Canyon Creek, 0.8 mi (1.3 km) above Pine Valley Cr., R 1, 28 / IV / 2009, Larvae (ABL); San Diego River, Headwaters above Hwy 79, 04 / V / 2010, Larvae (ABL); San Luis Rey River WF, 1 mi (1.6 km) N Mendenhall Valley, R 1, 28 / IV / 2009, Larvae (ABL); Santa Clara Co., Coyote Creek, Gilroy Hot Springs Road, 1.4 mi N Gilroy Hot Springs, 26 / VI / 2010, J. York, ♂ ♀; Ventura Co., Sespe Creek, Hwy 33, approximately 19.5 mi (31.4 km) NW of Wheeler Springs, 07 / VI / 2010, Larvae (ABL).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9DF11FFEEEFD5A90BEFD8F.taxon	description	Male larva. Body length of mature larva 9 – 10 mm. Dorsum of head mostly dark with fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus present but poorly defined, not connected to light frontoclypeus area, median longitudinal pigment band short, nearly square, lateral thin arms indistinct, directed posterolaterally and extending to antennal bases; posterior ocelli with completely enclosed small light areas along outer lateral margins; interocellar area mostly dark, usually a small unpigmented central area completely enclosed by dark pigment; occiput with irregular spinulae band extending from below eye to near median epicranial suture, partially to completely enclosed by indistinct dark pigment (Fig. 4 a). Lacinia bidentate, total length 653 – 919 µm (Fig. 2 b, 4 e- h, Tables 2 - 4); submarginal row (A + B) with 8 – 11 setae, groups A-B continuous below subapical tooth (SAT) inner margin (Figs. 4 gh); 3 – 5 submarginal (A) setae and 4 – 6 (B) setae in a row without gap between setae until past SAT inner margin, row extending from base of apical tooth (AT) to nearly lacinia lateral margin, the last 3 – 4 setae becoming widely spaced, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by apical tooth, first submarginal seta or broken, and 1 dorsal seta (DS) located below subapical tooth inner margin, partially obstructed from view by first few submarginal setae (Fig. 4 h); 10 – 13 marginal setae (C) initially long-stout and widely spaced, last few shorter, variably spaced and occasionally borne from dorsal surface (Figs. 4 e, 4 g); 12 – 27 ventral surface setae (D) scattered below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, occasionally a few setae below submarginal row striated (Fig. 4 f); dorsal surface setae (DSS) usually absent, sometimes last few marginal setae (C) form a short dorsal row (Fig. 4 f – arrow); 15 – 20 minute scale-like spinulae rarely present on and along ventral inner-lateral margin in basal half. Galea with 12 – 19 setae in sparse ventral row, apex with 2 – 3 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with indistinct and variable pigment pattern, median light area absent and fine dark clothing setae; discs occasionally with slightly darker comma shaped areas near lateral margins, lateral margins with broad light bands (Fig. 4 b). Meso and metanotum with indistinct pigment pattern and fine dark clothing setae (Fig. 4 c). Legs with numerous fine light brown clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated along dorsal surfaces; fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 b); tibia with faint transverse bands near proximal end. Abdominal terga without distinct longitudinal dark stripes; numerous fine light clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 4 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9DF11FFEEEFD5A90BEFD8F.taxon	distribution	Distribution. California: Sierra Nevada foothills.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9DF11FFEEEFD5A90BEFD8F.taxon	diagnosis	Diagnosis. The lacinia of male I. adunca larvae are distinctive in that the entire submarginal row (A + B) is continuous from the base of the apical tooth continuing to almost the inner lacinia margin (Figs. 4 g-h). Larvae lack distinct pigment patterns, especially longitudinal abdominal stripes. The lacinia of immature larvae are also distinct and resemble mature larvae, except that submarginal row (A + B) setae are more widely spaced.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9DF11FFEEEFD5A90BEFD8F.taxon	discussion	Remarks. Isoperla adunca inhabits mostly nonperennial and a few perennial foothill streams of the central Sierra Nevada range. It co-occurred with the following species: I. acula, I. marmorata, I. miwok, and Isoperla mormona Banks and emergence occurred in April – June.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	materials_examined	NEW LARVA DESCRIPTION	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	description	(Figs. 1 a-d, 2 c, 5 a-h, 20 c)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	materials_examined	Material examined. TYPES: I. baumanni, Holotype ♂, Allotype ♀, CA: Plumas Co., Domingo Springs Campground, 6 mi (9.7 km) NW Chester, Domingo Spring, 25 / VI / 1980, R. Baumann, J. Stanger (NMNH # 104070). Additional Specimens. CALIFORNIA: Plumas Co., Domingo Spring, Domingo Springs Campground, 8.5 mi (13.7 km) NW Chester on Old Red Bluff Rd., 20 / I / 2007, J. Sandberg, Larvae; 04 / II / 2007, Larvae; 24 / III / 2007, Larvae; 09 / VI / 2007, J. Sandberg, A. Richards, Larvae (reared); 13 / VI / 2007, J. Sandberg, ♂ ♀, Larvae (reared); 17 / VI / 2007, ♂ ♀, Larvae (reared); 07 / VII / 2007, ♂ ♀ Larvae; 03 / XI / 2007, Larvae; 02 / V / 2008, J. Sandberg, D. Pickard, Larvae; 17 / V / 2008, J. Sandberg, Larvae; 13 / VI / 2008, Larvae (reared); 20 / VI / 2008, ♂ ♀ Larvae (reared); 22 / VI / 2008, ♂ ♀, Larvae; 05 / VI / 2010, Larvae (reared); 03 / VII / 2010, ♂ ♀.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	description	Male larva. Body length of mature larva 9 – 10 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus usually connected to light frontoclypeus area by an apically narrowed median longitudinal light band, its width at mid length approximately equal to the width at base, lateral arms with irregular margins usually disconnected from median light band, directed posterolaterally, and extending to antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area partially light, completely enclosed by dark pigment, light area extending past posterior ocelli, not reaching dark pigment below the arms of the epicranial suture, light area generally oval shaped with acutely constricted base; occiput with irregular spinulae band extending from below eye to near median epicranial suture, completely enclosed by dark pigment (Figs. 1 d, 5 a). Lacinia bidentate, total length 1069 – 1256 µm (Figs. 1, 2 c, 5 e- h, Tables 2 - 4); submarginal row (A + B) with 7 – 10 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 5 g); 5 – 7 submarginal setae (A) in a close set row beginning at base of apical tooth (AT), ending before reaching SAT inner margin, row usually single, rarely 2 setae thick, plus 1 thin marginal setae (TMS) adjacent to AT inner margin, sometimes obstructed from view by the AT, submarginal setae (A), or broken, and 1 dorsal seta (DS) located below SAT inner margin, sometimes obstructed from view by SAT, submarginal setae (B), or broken (Fig. 5 h); 2 – 4 submarginal setae (B) located past SAT inner margin (Figs. 5 g-h); 15 – 27 marginal setae (C) initially longstout and widely spaced, usually several setae near end of row arranged in pairs protruding at dorsal and ventral angles, last few shorter and closer, blending into and difficult to differentiate from dorsal surface setae (Fig. 5 e); 38 – 71 ventral surface setae (D) scattered below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, occasionally a few setae below submarginal row striated (Fig. 5 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band, concentrated at junction with marginal setae (C), ending at approximately ½ or a little more the lacinia length (Fig. 5 e). Galea with 15 – 33 setae in sparse ventral row, apex with 2 – 3 setae. Maxillary Palp segments 2 – 3 with curved apically rounded setae (Fig. 5 e Inset). Pronotum with broad median light area bordered by thick dark comma shaped bands typical of the I. sobria complex; discs each with thick black clothing setae, those along median margins usually enclosed by indistinct light brown pigment, lateral margins with broad light bands (Fig. 5 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 5 c). Legs with numerous fine golden clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated along dorsal surfaces; fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 c); tibia with faint transverse bands near proximal end. Abdominal terga with three longitudinal dark stripes; wide light median longitudinal band bisected with thin light brown median longitudinal stripe present on distal segments; lateral pair of dark longitudinal stripes about twice as wide as median dark stripe, extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 5 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	distribution	Distribution. Northern California, known only from one Sierra Nevada high elevation spring.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	diagnosis	Diagnosis. The 5 – 7 submarginal (A) setae of I. baumanni male larvae (Figs. 5 g-h) are most similar to Isoperla sobria (Hagen) and I. tilasqua but differs from I. miwok with only one submarginal (A) seta (Fig. 11 g). The setae counts alone were not sufficient to separate the three species with multiple close set submarginal (A) setae; I. sobria with 3 – 4 submarginal (A) setae (Figs. 17 e, g-h) and 2 - 5 submarginal (A) setae for I. tilasqua (Figs. 19 e, g-h). It is suspected that increased variation will be observed as more populations are studied. The basal segments 2 – 3 of the maxillary palpi have long, thin, apically rounded setae (Fig. 5 e Inset) which are shared by I. tilasqua (Fig. 19 e Inset); I. sobria has long thin, apically pointed setae (Fig. 17 e Inset). The variably shaped and large I. baumanni interocellar light area is completely enclosed by dark pigment (Fig. 5 a), similar to I. sobria (Fig. 17 a), but the latter is usually an inverted V shape (or sometimes a very small light spot). The interocellar light area of I. tilasqua (Meacham Creek, Oregon population) is not completely enclosed by dark pigment, and continues past the posterolateral ocelli to the median base of the dorsal head capsule (Fig. 19 a). The light M shaped dorsal head pattern of I. tilasqua is a continuous line, but is interrupted in I. baumanni and I. sobria. A median longitudinal light band is present in all three species, but this line is approximately half as wide as the median base of the light M pattern in I. tilasqua (Fig. 19 a).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	discussion	Remarks. Isoperla baumanni may be restricted to Domingo Spring, Plumas County, a high volume and nearly stenothermic spring and emergence occurred in June – July. It was absent in nearby smaller Mosquito Spring containing both I. bifurcata and I. sobria, and an unnamed spring tributary to Gurnsey Creek with only I. bifurcata present. Recent collecting and rearing at Domingo Springs from 2006 – 2010 confirm three sympatric species: I. baumanni, I. bifurcata, and I. marmorata (three collected adults only). Isoperla bifurcata larvae were distributed throughout the spring and collected from all available submerged substrates (aquatic moss, aquatic plants, wood and rock). Isoperla baumanni larvae were primarily collected from submerged aquatic liverworts located in a small area along the southeastern bank, below the footbridge and above the cattle fence. Everted I. baumanni males (reared & collected) did not compare well with the original description and appears to be the result of using two methods for everting the aedeagus. The aedeagus illustrated by Szczytko & Stewart (1984 – Fig. 53) was cleared and then hyper everted and this method may not be directly comparable to males that were everted live. Attempts to produce a similar evertion as illustrated in Szczytko & Stewart (1984) resulted in bursting the aedeagus membrane. In the current study, 31 reared and fully everted males lacked the projected, conical, anterodorsal striated, bladelike tip. Instead, a small depression was visible in this area and when the freshly everted aedeagus was fixed in near boiling water, seminal fluid streamed from the depression. The absence of long, paired membranous lobes was also observed in I. fulva, I. miwok, and I. roguensis, emphasizing the difference between live everted specimens of the current study and hyper everted preserved specimens illustrated in previous studies. Perhaps the striated bladelike tip of the I. baumanni aedeagus as illustrated in Szczytko & Stewart (1984) is an internal valve, which controls the release of sperm during copulation. Two mature male larvae from Long Canyon Creek, El Dorado County, California were prepared for maxillae examination and tentatively identified as I. baumanni. The partly mature larvae with developing wing pads were collected on April 27 th, 2007, by Austin Brady Richards near Bendorf Spring. Both the males and females in the sample possessed an inverted V shaped light mark within the interocellar area, similar to I. sobria. One unsuccessful return trip by the author was conducted in early July, 2011, to attempt rearing and adult collection.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	description	(Figs. 2 d, 6 a-h, 20 d)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	materials_examined	Material examined. TYPES: I. bifurcata, Holotype ♂, OR: Union Co., ~ 6 mi (9.7 km) E Medical Springs, DFTM Proj., Lick Creek, 23 / VII / 1975, D. Dunster (NMNH # 76343); Allotype ♀, same location and collector, 30 / VI / 1976 (NMNH); Paratype ♂ ♀, same location and collector as Holotype, 23 / VII / 1975 (NMNH). Additional Specimens. CALIFORNIA: Butte Co., Butte Creek, Butte Meadows Campground, Humbug Rd., Butte Meadows, 30 / III / 2007, J. Sandberg, Larvae; Butte Creek, Cherry Hill Campground, Humbug Rd., 9 mi (14.5 km) NE Lomo (Hwy 32), 18 / II / 2007, J. Sandberg, D. Pickard, Larvae. El Dorado Co., NF Cosumnes River, Headwaters below Singleton Springs, E Grizzly Flat, 22 / VI / 1987, R. Bottorff, Larvae (NMNH); NF Cosumnes River, Headwaters below Singleton Springs, E Grizzly Flat, 22 / VI / 1987, R. Bottorff, Larvae (CAS). Fresno Co., Huntington Lake, 07 / VII / 1919, F. Blasdell, ♂ (NMNH). Plumas Co., Domingo Spring, Domingo Springs Campground, 8.5 mi (13.7 km) NW Chester on Old Red Bluff Rd., 12 / VIII / 2006, J. Sandberg, J. Slusark, Larvae; 01 / X / 2006, J. Sandberg, ♂ ♀, Larvae (mature and early instar); 10 / XII / 2006, Larvae; 20 / I / 2007, Larvae; 04 / II / 2007, Larvae; 24 / III / 2007, Larvae; 22 / IV / 2007, Larvae (reared); 06 / V / 2007, J. Sandberg, D. Pickard, Larvae; 19 / V / 2007, J. Sandberg, S. Hassur, Larvae (reared); 28 / V / 2007, J. Sandberg, D. Pickard, Larvae (reared); 09 / VI / 2007, J. Sandberg, A. Richards, ♂, Larvae (reared), Exuviae; 13 / VI / 2007, J. Sandberg, ♂ ♀, Larvae (reared); 17 / VI / 2007, ♂ ♀; 07 / VII / 2007, ♂ ♀; 01 / VIII / 2007, ♀, Larvae; 16 / IX / 2007, ♂ ♀, Larvae; 21 / IX / 2007, ♂ ♀, Larvae; 30 / IX / 2007, ♀; 03 / XI / 2007, ♂ ♀, Larvae; 20 / V / 2008, J. Sandberg, D. Pickard, Larvae; 17 / V / 2008, Larvae; 13 / VI / 2008, ♂ ♀; 20 & 22 / VI / 2008, ♂ ♀; 06 / IX / 2008, ♂ - ♀; 05 / VI / 2010, Larvae (reared); 03 / VII / 2010, ♂; Mosquito Creek (East Branch), 0.6 mi (1 km) E of Domingo Springs, 7.9 mi (12.7 km) W of Chester, 04 / II / 2007, J. Sandberg, Larvae; 01 / IV / 2007, Larvae; Mosquito Creek (West Branch), 0.4 mi (0.6 km) E of Domingo Springs, 8.1 mi (13.0 km) W of Chester, 04 / II / 2007, J. Sandberg, Larvae; 24 / III / 2007, Larvae; 22 / IV / 2007, J. Sandberg, D. Pickard, Larvae (reared); 19 / V / 2007, J. Sandberg, S. Hassur, Larvae (reared); 28 / V / 2007, J. Sandberg, D. Pickard, ♂, Larvae (reared); 13 / VI / 2007, J. Sandberg, ♂ ♀, Larvae (reared); 01 / VIII / 2007, Larvae; 11 / VIII / 2007, Larvae; 16 / IX / 2007, Larvae; 21 / IX / 2007, Larvae; 03 / XI / 2007, Larvae; 17 / V / 2008, Larvae; 13 / VI / 2008, Larvae (reared); 20 / VI / 2008, ♂ ♀, Larvae (reared); 05 / VI / 2010, Larvae; 03 / VII / 2010, ♂ ♀. Siskiyou Co., Big Springs Creek, Big Springs Park, Nixon Rd., Mt. Shasta, 13 / V / 2007, J. Sandberg, D. Pickard, Larvae. Tehama Co., Spring Trib of Gurnsey Creek, Gurnsey Creek Campground, Hwy 36, 2.3 mi (3.7 km) N Hwy 32 Intersec., 26 / IV / 2010, R. Baumann, B. Kondratieff, A. Richards, J. Sandberg, J. Slusark, Larvae (reared). Trinity Co.,?, Carrville,? / VI / 1913, E. C. VanDyke, ♂ ♀ (CAS). Tulare Co., Marble Fork Kaweah River, Sequoia Nat. Pk., 24 / VII / 1907, J. Bradley, ♂ (NMNH). OREGON: Union Co., Lick Creek, about 6 mi (9.6 km) E Medical Springs, 30 / VI / 1976, D. Dunster, ♀ (NMNH). Male larva. Body length of mature larva 9 – 11 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus connected to light frontoclypeus area by broad median longitudinal light band, lateral thin arms directed posterolaterally, and extending to antennal bases; posterior ocelli with completely enclosed small light areas along outer lateral margins; interocellar area partially light and variable, from completely enclosed by dark pigment to open posteriorly and connected to light area below occipital spinulae band; occiput with irregular spinulae band extending from below eye to near median epicranial suture, enclosed by dark and light brown pigment (Fig. 6 a). Lacinia bidentate, total length 666 – 967 µm (Figs. 2 d, 6 e- h, Tables 2 - 4); submarginal row (A + B) with 2 – 4 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Figs. 6 g-h); 1 – 2 submarginal setae (A) the first inserted at base of apical tooth (AT) inner margin, the second when present, located between SAT and AT inner margins, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT, submarginal setae (A), or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT or submarginal setae (B) (Figs. 6 g-h); 1 – 2 submarginal setae (B) located past SAT inner margin (Figs. 6 g-h); 8 – 11 marginal setae (C) initially long-stout and widely spaced, last few shorter and closer, blending into and difficult to differentiate from dorsal surface setae (Fig. 6 e); 17 – 38 ventral surface setae (D) scattered below submarginal and marginal setae ending posteriorly at approximately ¾ the inner lacinia margin length (Fig. 6 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending before posterior-most ventral surface seta (Fig. 6 f). Galea with 37 – 50 setae in thick ventral band, apex with 4 – 6 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum generally light brown, median light area bordered laterally by dark brown pigment and light rugosites; discs each with thin, dark brown comma shaped areas near lateral margins and fine dark clothing setae, lateral margins with broad light bands (Fig. 6 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 6 c). Legs with numerous fine dark clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated along dorsal surfaces; fine silky setae sparse on dorsal surface of femora, numerous but not continuous on tibia (Fig. 20 d); tibia with very faint transverse bands near proximal end. Abdominal terga with two distinct longitudinal dark stripes; wide light median longitudinal band occasionally appears bisected by muscle attachment scars; lateral pair of dark longitudinal stripes usually not extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 6 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	distribution	Distribution. Northern California (Sierra Nevada high elevation springs and creeks), Idaho, and Oregon.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	diagnosis	Diagnosis. Male larvae of I. bifurcata are most similar to I. acula and can be separated by having fine silky setae sparse on dorsal surface of femora, numerous but not continuous on tibia (Fig. 20 d), and abdomen without a distinct median dark stripe (Fig. 6 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF9FF100FC2CFD5A9621FE79.taxon	discussion	Remarks. This species was the lone Isoperla species or occurred with either I. baumanni or I. sobria in small to large, mid-elevation spring creeks in the Sierra Nevada range of California. Emergence was extended at Domingo and Mosquito Springs, Plumas County, and occurred in May – October. An extended summer-fall emergence was also observed for I. laucki.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF80F105FC02FE089276FD70.taxon	description	(Figs. 2 d, 6 a-h, 20 d)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF80F105FC02FE089276FD70.taxon	materials_examined	Material examined. TYPES: I. bifurcata, Holotype ♂, OR: Union Co., ~ 6 mi (9.7 km) E Medical Springs, DFTM Proj., Lick Creek, 23 / VII / 1975, D. Dunster (NMNH # 76343); Allotype ♀, same location and collector, 30 / VI / 1976 (NMNH); Paratype ♂ ♀, same location and collector as Holotype, 23 / VII / 1975 (NMNH). Additional Specimens. CALIFORNIA: Butte Co., Butte Creek, Butte Meadows Campground, Humbug Rd., Butte Meadows, 30 / III / 2007, J. Sandberg, Larvae; Butte Creek, Cherry Hill Campground, Humbug Rd., 9 mi (14.5 km) NE Lomo (Hwy 32), 18 / II / 2007, J. Sandberg, D. Pickard, Larvae. El Dorado Co., NF Cosumnes River, Headwaters below Singleton Springs, E Grizzly Flat, 22 / VI / 1987, R. Bottorff, Larvae (NMNH); NF Cosumnes River, Headwaters below Singleton Springs, E Grizzly Flat, 22 / VI / 1987, R. Bottorff, Larvae (CAS). Fresno Co., Huntington Lake, 07 / VII / 1919, F. Blasdell, ♂ (NMNH). Plumas Co., Domingo Spring, Domingo Springs Campground, 8.5 mi (13.7 km) NW Chester on Old Red Bluff Rd., 12 / VIII / 2006, J. Sandberg, J. Slusark, Larvae; 01 / X / 2006, J. Sandberg, ♂ ♀, Larvae (mature and early instar); 10 / XII / 2006, Larvae; 20 / I / 2007, Larvae; 04 / II / 2007, Larvae; 24 / III / 2007, Larvae; 22 / IV / 2007, Larvae (reared); 06 / V / 2007, J. Sandberg, D. Pickard, Larvae; 19 / V / 2007, J. Sandberg, S. Hassur, Larvae (reared); 28 / V / 2007, J. Sandberg, D. Pickard, Larvae (reared); 09 / VI / 2007, J. Sandberg, A. Richards, ♂, Larvae (reared), Exuviae; 13 / VI / 2007, J. Sandberg, ♂ ♀, Larvae (reared); 17 / VI / 2007, ♂ ♀; 07 / VII / 2007, ♂ ♀; 01 / VIII / 2007, ♀, Larvae; 16 / IX / 2007, ♂ ♀, Larvae; 21 / IX / 2007, ♂ ♀, Larvae; 30 / IX / 2007, ♀; 03 / XI / 2007, ♂ ♀, Larvae; 20 / V / 2008, J. Sandberg, D. Pickard, Larvae; 17 / V / 2008, Larvae; 13 / VI / 2008, ♂ ♀; 20 & 22 / VI / 2008, ♂ ♀; 06 / IX / 2008, ♂ - ♀; 05 / VI / 2010, Larvae (reared); 03 / VII / 2010, ♂; Mosquito Creek (East Branch), 0.6 mi (1 km) E of Domingo Springs, 7.9 mi (12.7 km) W of Chester, 04 / II / 2007, J. Sandberg, Larvae; 01 / IV / 2007, Larvae; Mosquito Creek (West Branch), 0.4 mi (0.6 km) E of Domingo Springs, 8.1 mi (13.0 km) W of Chester, 04 / II / 2007, J. Sandberg, Larvae; 24 / III / 2007, Larvae; 22 / IV / 2007, J. Sandberg, D. Pickard, Larvae (reared); 19 / V / 2007, J. Sandberg, S. Hassur, Larvae (reared); 28 / V / 2007, J. Sandberg, D. Pickard, ♂, Larvae (reared); 13 / VI / 2007, J. Sandberg, ♂ ♀, Larvae (reared); 01 / VIII / 2007, Larvae; 11 / VIII / 2007, Larvae; 16 / IX / 2007, Larvae; 21 / IX / 2007, Larvae; 03 / XI / 2007, Larvae; 17 / V / 2008, Larvae; 13 / VI / 2008, Larvae (reared); 20 / VI / 2008, ♂ ♀, Larvae (reared); 05 / VI / 2010, Larvae; 03 / VII / 2010, ♂ ♀. Siskiyou Co., Big Springs Creek, Big Springs Park, Nixon Rd., Mt. Shasta, 13 / V / 2007, J. Sandberg, D. Pickard, Larvae. Tehama Co., Spring Trib of Gurnsey Creek, Gurnsey Creek Campground, Hwy 36, 2.3 mi (3.7 km) N Hwy 32 Intersec., 26 / IV / 2010, R. Baumann, B. Kondratieff, A. Richards, J. Sandberg, J. Slusark, Larvae (reared). Trinity Co.,?, Carrville,? / VI / 1913, E. C. VanDyke, ♂ ♀ (CAS). Tulare Co., Marble Fork Kaweah River, Sequoia Nat. Pk., 24 / VII / 1907, J. Bradley, ♂ (NMNH). OREGON: Union Co., Lick Creek, about 6 mi (9.6 km) E Medical Springs, 30 / VI / 1976, D. Dunster, ♀ (NMNH). Male larva. Body length of mature larva 9 – 11 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus connected to light frontoclypeus area by broad median longitudinal light band, lateral thin arms directed posterolaterally, and extending to antennal bases; posterior ocelli with completely enclosed small light areas along outer lateral margins; interocellar area partially light and variable, from completely enclosed by dark pigment to open posteriorly and connected to light area below occipital spinulae band; occiput with irregular spinulae band extending from below eye to near median epicranial suture, enclosed by dark and light brown pigment (Fig. 6 a). Lacinia bidentate, total length 666 – 967 µm (Figs. 2 d, 6 e- h, Tables 2 - 4); submarginal row (A + B) with 2 – 4 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Figs. 6 g-h); 1 – 2 submarginal setae (A) the first inserted at base of apical tooth (AT) inner margin, the second when present, located between SAT and AT inner margins, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT, submarginal setae (A), or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT or submarginal setae (B) (Figs. 6 g-h); 1 – 2 submarginal setae (B) located past SAT inner margin (Figs. 6 g-h); 8 – 11 marginal setae (C) initially long-stout and widely spaced, last few shorter and closer, blending into and difficult to differentiate from dorsal surface setae (Fig. 6 e); 17 – 38 ventral surface setae (D) scattered below submarginal and marginal setae ending posteriorly at approximately ¾ the inner lacinia margin length (Fig. 6 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending before posterior-most ventral surface seta (Fig. 6 f). Galea with 37 – 50 setae in thick ventral band, apex with 4 – 6 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum generally light brown, median light area bordered laterally by dark brown pigment and light rugosites; discs each with thin, dark brown comma shaped areas near lateral margins and fine dark clothing setae, lateral margins with broad light bands (Fig. 6 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 6 c). Legs with numerous fine dark clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated along dorsal surfaces; fine silky setae sparse on dorsal surface of femora, numerous but not continuous on tibia (Fig. 20 d); tibia with very faint transverse bands near proximal end. Abdominal terga with two distinct longitudinal dark stripes; wide light median longitudinal band occasionally appears bisected by muscle attachment scars; lateral pair of dark longitudinal stripes usually not extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 6 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF80F105FC02FE089276FD70.taxon	distribution	Distribution. Northern California (Sierra Nevada high elevation springs and creeks), Idaho, and Oregon.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF80F105FC02FE089276FD70.taxon	diagnosis	Diagnosis. Male larvae of I. bifurcata are most similar to I. acula and can be separated by having fine silky setae sparse on dorsal surface of femora, numerous but not continuous on tibia (Fig. 20 d), and abdomen without a distinct median dark stripe (Fig. 6 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF80F105FC02FE089276FD70.taxon	discussion	Remarks. This species was the lone Isoperla species or occurred with either I. baumanni or I. sobria in small to large, mid-elevation spring creeks in the Sierra Nevada range of California. Emergence was extended at Domingo and Mosquito Springs, Plumas County, and occurred in May – October. An extended summer-fall emergence was also observed for I. laucki.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF85F107FED7FD0397C9F88E.taxon	description	(Figs. 2 e, 7 a-h, 20 e)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF85F107FED7FD0397C9F88E.taxon	materials_examined	Material examined. TYPE: I. denningi, Holotype ♂, CA: Los Angeles Co., Monroe Canyon?, 4 mi W Tanbark Flats, 21 / IV / 1950, H. L. Hanson (CAS # 8583). Paratype ♀, same location as Holotype, 21 / IV / 1950, H. L. Hanson (CAS). Additional Specimens. CALIFORNIA: Los Angeles Co., Arroyo Sequit, Mulholland Dr., 1.5 mi (2.4 km) N Hwy 101, S of Solromar, 29 / IV / 2002, Larvae (ABL); Elizabeth Canyon Creek, Lake Hughes Rd., ~ 10 mi (16.1 km) E I- 5, 1 / V / 2002, Larvae (ABL); ~ 0.6 mi (1.0 km) below Prospect Canyon, Winter 2003, Larvae, (ABL); Encinal Canyon Creek, ~ 0.5 mi (0.8 km) above mouth, T 1, 4 / VI / 2008, Larvae (ABL); Little Rock Creek, Forest Service Route 5 N 04, ~ 0.4 mi (0.6 km) below Kitter Canyon Creek, R 1, 15 / V / 2008, Larvae (ABL), San Diego Co., Boulder Creek, Boulder Creek Rd., 13.9 mi (22.4 km) N Descanso, 01 / V / 2007, J. Sandberg, Larvae; Cañada Verde, Hwy 79 at Pacific Crest Trail, 1.1 mi (1.8 km) S Warner Springs, 10 / V / 2010, 15 / VI / 2010, Larvae (ABL); Carney Canyon Creek, Pamo Valley, 7.5 mi (12.1 km) N Ramona, 12 / V / 2010, Larvae (ABL); Cedar Creek, ~ 1.5 mi (2.4 km) above San Diego River, 12 / V / 2009, Larvae (ABL); Cold Stream, Hwy 79, 9.9 mi (15.9 km) N Hwy 8, near intersection with Pipeline Fire Rd., 03 / V / 2007, J. Sandberg, Larvae; Conejos Creek, at El Capitan Reservoir, 14 / IV / 2008, Larvae (ABL); Cottonwood Creek, Downstream of Old Hwy 80 crossing, 04 / V / 2007, Larvae (ABL); De Luz Creek, De Luz Murrieta Rd., 2.9 mi (4.7 km) NE De Luz, 16 - 17 / IV / 2010, J. Sandberg, D. Pickard, Larvae (reared 1 male); Fry Creek, New Fry Creek Campground W side of Canfield Rd., 2.9 mi (4.7 km) N Cty Hwy S 7 (6), 06 / V / 2008, J. Sandberg, D. Pickard, Larvae; Japacha Creek, above Hwy 79 crossing, 3.7 mi (5.9 km) S Paso Picacho Campground, 7.9 mi (12.7 km) N Hwy 8, 08 / VI / 2010, Larvae (ABL); Pine Creek, Pine Creek Road, 3.9 mi (6.3 km) N Pine Valley off Old Hwy 80, 02 / V / 2007, J. Sandberg, Larvae; Pine Valley Creek, ~ 1.6 mi (2.6 km) above Hwy 8, 01 / VII / 2006, Larvae (ABL); Pine Valley Creek, ~ 2.3 mi above Secret Canyon Creek, 05 / V / 2009, Larvae (ABL); Pine Valley Creek, Below Nobel Canyon Creek, 05 / V / 2009, Larvae (ABL); Roblar Creek, 0.36 mi (0.6 km) E Camp De Luz Rd. crossing, Camp Pendleton USMC, 18 / IV / 2008, J. Sandberg, Larvae (not reared); San Luis Rey River WF, 1 mi (1.6 km) N Mendenhall Valley, R 1, 28 / IV / 2009, Larvae (ABL); San Mateo Creek, San Mateo Canyon, Tenaja Trail crossing at Tenaja Truck Trail & Los Alamos Rd., 05 / V / 2008, 16 / IV / 2010, J. Sandberg, D. Pickard, Larvae (rearing failed); Santa Ysabel Creek, at Hwy 79, 24 / IV / 2008, Larvae (ABL); Santa Ysabel Creek, Below Clevenger Canyon Creek, 29 / IV / 2009, Larvae (ABL); Stone Creek, 0.41 mi (0.7 km) upstream from S. Stagecoach Lane crossing, 06 / V / 2008, J. Sandberg, D. Pickard, Larvae (reared); Sweetwater River, Wildwood Glen Lane bridge, 0.1 mi (0.2 km) W Hwy 79 near Los Terrentos, 04 / V / 2007, J. Sandberg, Larvae; Temescal Creek, Pamo Road, 8 mi (12.9 km) N Ramona, N 33.17601, W 116.85052, 13 / VI / 2010, Larvae (ABL); Troy Canyon Creek, near Troy Flat off Kitchen Creek Rd., 3.6 mi (5.8 km) S Sunrise Hwy, 02 / V / 2007, J. Sandberg, Larvae; Santa Barbara Co., Jalama Creek, Jalama Rd at railroad crossing, 2.5 mi W of Jalama Ranch, 06 / V / 2008, Larvae (ABL); La Brea Creek, FR 10 N 06 crossing, 3.6 mi (5.8 km) E Hwy 176 intersection ,, Larvae (ABL); Ventura Co., Cold Creek, Cold Creek Middle, Duplicate, 03 / V / 2010, Larvae (ABL).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF85F107FED7FD0397C9F88E.taxon	description	Male larva. Body length of mature larva 11 – 12 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus usually not connected to light frontoclypeus area, median longitudinal light band thin with parallel margins, lateral thin arms directed posterolaterally, extending to antennal bases; posterior ocelli with completely enclosed small light areas along outer lateral margins; interocellar area variable, usually its entire area lighter than surrounding dark pigment, partially filled with indistinct light brown pigment, extending past posterior ocelli and connected to light area below occipital spinulae band, occasionally interocellar area partially filled with surrounding dark pigment and not connected to light area of posterior head capsule; occiput with irregular spinulae band extending from below eye to near median epicranial suture, partially enclosed by light brown pigment (Fig. 7 a). Lacinia bidentate, total length 756 – 1093 µm (Figs. 2 e, 7 e- h, Tables 2 - 4); submarginal row (A + B) with 3 – 4 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 7 g); 1 submarginal seta (A) inserted at base of apical tooth (AT) inner margin, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT, submarginal seta (A) or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT or submarginal setae (B) (Figs. 7 gh); 2 – 3 submarginal setae (B) located past SAT inner margin (Figs. 7 g-h); 9 – 13 marginal setae (C) initially long-stout and widely spaced, last few shorter and widely spaced, sometimes borne from ventral or dorsal surface or broken with visible sockets (Fig. 7 e); 11 – 34 ventral surface setae (D) scattered below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length and concentrated in apical half, occasionally a few setae located below submarginal row striated (Fig. 7 f); dorsal surface setae (DSS) usually absent, sometimes last few marginal setae (C) form a short dorsal row (Fig. 7 f – arrow). 15 – 25 minute scale-like spinulae on and along dorsal inner-lateral margin in basal half. Galea with 35 – 48 setae in thick ventral band, apex with 4 – 5 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with thin, median light area bordered by irregular dark longitudinal bands with adjacent light rugosites; discs each with dark comma shaped lateral areas and fine dark clothing setae restricted to areas of dark pigmentation, lateral margins with broad light bands (Fig. 7 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 7 c). Legs with numerous fine golden clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated on dorsal surface; fine silky setae numerous and continuous on dorsal surfaces of femora and tibia (Fig. 20 e); tibia with faint transverse bands near proximal end. Abdominal terga with two distinct longitudinal dark stripes; wide light median longitudinal band bisected with indistinct light brown median pigment band; lateral pair of dark longitudinal stripes not extending to lateral margins; numerous fine light clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 7 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF85F107FED7FD0397C9F88E.taxon	distribution	Distribution. Isoperla denningi is the common Isoperla species distributed throughout southern California. Previous northern California records from Fresno, Placer, Tuolumne, Tehama and Trinity counties (Szczytko & Stewart 1979, 2002) were not confirmed in this study. Larvae and exuviae collected from Secret Ravine Creek, Placer County keyed to I. marmorata.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF85F107FED7FD0397C9F88E.taxon	diagnosis	Diagnosis. The larval male lacinia of I. denningi is distinct from other Isoperla species with 1 – 4 submarginal (A + B) setae in that the dorsal lacinial surface has no fine setae (must focus down through ventral surface to see) and ventral surface setae (D) are concentrated on the apical half (Fig. 7 f). The larval dorsal head pigment pattern is striking in this species, which has a well defined median longitudinal light band extending from the median base of the M shaped mark, almost reaching the anterior unpigmented frontoclypeus area (Figs. 7 a- d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF85F107FED7FD0397C9F88E.taxon	discussion	Remarks. This species was usually the only Isoperla in streams within its range, but co-occurred in a few southern California streams with the following species: I. acula, I. adunca, and I. mormona. Isoperla denningi was the ubiquitous species south of Monterey, Kings, Tulare, and Inyo counties. Emergence occurred in April – June, was lightly extended, and was determined from adult collections and limited rearing.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF86F108FED2FF3592AAFAD3.taxon	description	(Figs. 2 f, 8 a-h, 20 f)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF86F108FED2FF3592AAFAD3.taxon	materials_examined	Holotype ♂, Logan River, Cache Co., Utah.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF86F108FED2FF3592AAFAD3.taxon	materials_examined	Material examined. COLORADO: Boulder Co., SF Middle Boulder Creek, TR 901, 3 mi (4.8 km) W Hessie, 6 mi (9.6 km) W Eldora, 23 / VIII / 1997, J. Sandberg, Larvae (reared); Gunnison Co., Beaver Creek, at Beaver Creek Picnic Area near confluence with Gunnison River, 24 / V / 1997, J. Sandberg, Larvae (reared); Quartz Creek, Pitkin, The Ken & Francine Stewart Cabin, 07 / VII / 1999, J. Sandberg, ♂ ♀, Larvae (reared); Larimer Co., Cache la Poudre River ,, 13 / VI / 1998, J. Sandberg, ♂ ♀, Larvae; Saguache Co., Cochetopa Creek, Hwy 114 between UU- 13 & 14 - PP Roads, S of Hwy 50, 06 / VI / 2003, J. Sandberg, Larvae (reared); OREGON: Douglas Co., Cow Creek, at Quines Creek, 08 / IV / 1968, S. Jewett Jr., ♂ ♀ not everted (NMNH); Jackson Co., Applegate River, 10 mi (16.1 km) S Ruch, 22 / V / 1964, J. Schuh, ♂ ♀ (NMNH); Jefferson Co.,?, Palisades State Park, 14 / V / 1954, S. Jewett Jr., ♂ (NMNH); Klamath Co., Crescent Creek, Rt. 58, 39 mi (62.8 km) E Oakridge, 25 / VI / 1985, C. & O. Flint, Jr., ♀ (NMNH); Sprague River, near Bly, 02 / VI / 1972, D, Denning, ♂ (damaged) (NMNH); Wallowa Co., Wallowa River, Wallowa Mts., Johnson Street Park, 02 / VII / 1948, C. Alexander, ♂ ♀, (poor condition) (NMNH); Wallowa River, Minam, 2700 feet, 21 / VII / 1929, H. Scullen, ♂ (NMNH); WASHINGTON: Columbia Co., Tucannan River, Hwy 410 (12), 1940 feet, 20 / IV / 1968, E. Evans, ♂ (NMNH). Male larva. Body length of mature larva 9 – 10 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus indistinct, not connected to light frontoclypeus area, median longitudinal light band usually oval, lateral thin arms variable, sometimes directed posterolaterally and extending to antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area variable, from completely dark to partially light and completely enclosed by dark pigment, light area not extending past posterior ocelli; occiput with irregular spinulae band extending from below eye to near median epicranial suture, not enclosed completely by dark pigment (Fig. 8 a). Lacinia bidentate, total length 688 – 829 µm (Figs. 2 f, 8 e-h, Tables 2 - 4); submarginal row (A + B) with 2 – 3 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Figs. 8 g-h); 1 submarginal seta (A) inserted at base of apical tooth (AT) inner margin, plus 1 thin marginal seta (TMS) adjacent to AT inner margin sometimes obstructed from view by AT, submarginal seta (A) or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT or submarginal setae (B) (Figs. 8 g-h); 1 – 2 submarginal setae (B) located past SAT inner margin (Fig. 8 h); 6 – 11 marginal setae (C), initially long-stout and widely spaced, last few shorter and closer, blending into and difficult to differentiate from dorsal and ventral surface setae (Fig. 8 e); 64 – 109 ventral surface setae (D) forming dense longitudinal band below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, setae closest to inner margin protrude laterally past lacinia margin (Fig. 8 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending before posterior-most ventral surface setae (Fig. 8 f). Galea with 28 – 44 setae in thick ventral band, apex with 3 – 6 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with median light area bordered by wide dark bands typical of the I. marmorata group; discs each with light rugosites, irregular median dark margins and fine dark clothing setae, lateral margins with broad light bands (Fig. 8 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 8 c). Legs with numerous fine golden clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated on dorsal surface; fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 f); tibia with very faint transverse bands near proximal end. Abdominal terga with two distinct longitudinal dark stripes; wide light median longitudinal band bisected with indistinct light brown median pigment band; lateral pair of dark longitudinal stripes usually not extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 8 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF86F108FED2FF3592AAFAD3.taxon	distribution	Distribution. Canada: Alberta, British Columbia. USA: Arizona, California?, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming (Szczytko & Stewart 1979). The California listing was not confirmed during this study but adults need to be reared from Eagle Creek in the western Warner Mountains of Modoc County.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF86F108FED2FF3592AAFAD3.taxon	diagnosis	Diagnosis. The male larvae of I. fulva are most similar to other western species of the I. marmorata complex. They all share dark pigmented bodies and the pronotum is almost completely dark except for the median light band and lateral margins (Figs. 8, 10, 16 a-d). The lacinia of these species is also similar. The larvae of I. fulva larvae are inseparable from I. roguensis (Figs. 16 a-h & 20 n), but both can be distinguished from I. marmorata by the lack of a median longitudinal light band connecting the light M shaped pattern to the unpigmented frontoclypeus (Fig. 8 a).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF86F108FED2FF3592AAFAD3.taxon	discussion	Remarks. This species was not collected during this study from California. Eagle Creek, a Modoc County stream may contain this species; however, to confirm this, rearing is required.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF88F10AFEA2FAE7923DFC37.taxon	description	(Figs. 2 g, 9 a-h, 20 g)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF88F10AFEA2FAE7923DFC37.taxon	materials_examined	Material examined. CALIFORNIA: Humboldt Co., Dragsaw Spring, FR 13 N 02 crossing, 12 - 13 / VII / 2009, 10 - 12 / VII / 2010, J. Sandberg, Larvae (reared).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF88F10AFEA2FAE7923DFC37.taxon	description	Male larva. Body length of mature larva 9 – 10 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus a distinct thin band, not connected to light frontoclypeus area, median longitudinal light band absent, lateral thin arms directed posterolaterally, extending to antennal bases; posterior ocelli with completely enclosed small light areas along outer lateral margins; interocellar area entirely dark; occiput with irregular spinulae band extending from below eye to near median epicranial suture, usually enclosed completely by dark pigment (Fig. 9 a). Lacinia bidentate, total length 839 – 938 µm (Figs. 2 g, 9 e- h, Tables 2 - 4); submarginal row (A + B) with 4 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 9 g); 1 – 2 submarginal setae (A), the first located at base of apical tooth (AT) inner margin, the second when present, located between the AT and SAT inner margins, shorter and half as stout at base than first, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT, submarginal seta (A) or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT (Figs. 9 gh); 2 – 3 submarginal setae (B) located past SAT inner margin (Fig. 9 h); 7 – 9 marginal setae (C), initially long-stout and widely spaced, last few shorter and widely spaced, blending into and difficult to differentiate from dorsal surface setae (Fig. 9 e); 8 – 13 ventral surface setae (D) scattered below marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, mostly concentrated in posterior half (Fig. 9 f); dorsal surface setae (DSS) continue from last marginal setae (C) as a single, laterally protruding, submarginal row (sometimes 2 – 3 setae thick) along inner-lateral margin, ending before posterior-most ventral surface setae (Fig. 9 f). Galea with 28 – 44 setae in thick ventral band, apex with 4 – 7 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with thin median light line bordered by irregular dark longitudinal bands with adjacent light rugosites; discs each with dark comma shaped lateral areas, fine dark clothing setae restricted to areas of dark pigmentation and lateral margins without broad light bands (Fig. 9 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 9 c). Legs with numerous fine golden clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated on dorsal surface; fine silky setae sparse on dorsal surfaces of femora and tibia (Fig. 20 g); tibia with faint transverse bands near proximal end. Abdominal terga without distinct longitudinal dark stripes; tergites marked with a close set pair of dorsal small light spots and a wide set triplet of light spots laterally; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 9 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF88F10AFEA2FAE7923DFC37.taxon	distribution	Distribution. Known only from four Humboldt County streams (Bauman & Lee 2009).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF88F10AFEA2FAE7923DFC37.taxon	diagnosis	Diagnosis. Male larvae of I. laucki can be distinguished from other western Isoperla species with 1 – 2 submarginal setae (A) by the presence of 8 – 13 ventral lacinia surface setae (Figs 9 e-h), fine silky setae sparse on dorsal surfaces of femora and tibia, the interocellar area completely dark (Fig. 9 a), and abdomen lacking longitudinal stripes (Fig. 9 d). This species is most similar to I. adunca (Figs. 4 a-h & 20 b) in that it lacks abdominal stripes (Fig. 9 d), but can be separated by the interrupted lacinia submarginal setae row (Fig. 9 g).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF88F10AFEA2FAE7923DFC37.taxon	discussion	Remarks. This species was the only Isoperla species in four Humboldt County spring fed streams (Baumann & Lee 2009).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8AF10FFF7CFBC391B7FDC6.taxon	description	(Figs. 2 h, 10 a-h, 20 h)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8AF10FFF7CFBC391B7FDC6.taxon	materials_examined	Holotype ♀, Reno, Washoe Co., Nevada.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8AF10FFF7CFBC391B7FDC6.taxon	materials_examined	Material examined. CALIFORNIA: Butte Co.,?, 9 mi (14.5 km) N Oroville, 24 / IV / 1955, S. Hitchcock, Larvae (NMNH);?, Chico, 23 / IV / 1923, E. VanDuzee, ♂ (NMNH); Big Chico Creek, CSU-Chico near Holt Hall, 29 / III / 2007, 08 / IV / 2008, J. Sandberg, ♂ ♀; Big Chico Creek, Five-Mile Recreation Area, Centennial Ave. & Crow Canyon Ct., 27 / III / 2010, J. Sandberg, Larvae (reared); Butte Creek, 400 meters upstream from Doe Mill Road bridge, 28 / V / 2006, J. Sandberg, D. Pickard, Larvae (reared); Butte Creek, Butte Creek Ecological Reserve, Honey Run Rd., 2.9 mi (4.7 km) E intersection with Skyway, 11 / III / 2010, J. Sandberg, J. York, Larvae (reared); Mud Creek, Richardson Springs, 15 / IV / 2010, J. Sandberg, D. Pickard, J. York, Larvae (reared); Contra Costa Co.,?, near Moraga, 26 / IV / 1966, D. Denning, ♀ (poor condition) (NMNH); El Dorado Co., Deadman Creek, Church Mine Rd. crossing, 2.45 mi (3.9 km) SE El Dorado, 05 / IV / 2009, J. Sandberg, A. Richards, Larvae (reared); Greenwood Creek, Greenwood Creek Park, Hwy 49, 4 mi (6.4 km) E Pilot Hill, 28 / III / 2009, 11 / IV / 2009, J. Sandberg, Larvae (reared); Martinez Creek, Martinez Creek Rd., 3.5 mi (5.6 km) SE El Dorado, 04 / IV / 2009, J. Sandberg, D. Pickard, Larvae (reared); NF Cosumnes River, Hwy 49 Nashville, 31 / V / 1982, R. Bottorff, ♀ (NMNH); NF Cosumnes River, Hwy 49 cattle corral, 1.7 mi (2.7 km) S Nashville below confluence with MF Cosumnes River, 28 / IV / 2007, 28 / III / 2009, 30 / III / 2009, 11 / IV / 2009; J. Sandberg, 05 / IV / 2009; J. Sandberg, A. Richards, 11 / IV / 2009; J. Sandberg, Larvae (reared); Weber Creek, Forni Road bridge crossing at Placerville, 28 / III / 2009, J. Sandberg, Larvae (reared); Humboldt Co., Mad River, Arcata Bottoms, Mad River Rd., N 40.91578 º W 124.10618 °, 10 / IV / 2010, J. Sandberg, ♀; Nevada Co., Sagehen Creek, at diversion structure, 6300 feet, 18 / VI / 1965, A. Sheldon, ♀ (NMNH); Placer Co., Secret Ravine, Rocklin Road bridge crossing at Rocklin, 11 / IV / 2008, J. Sandberg, A. Richards, Larva; Plumas Co., Domingo Spring, Domingo Springs Campground, 8.5 mi (13.7 km) NW Chester on Old Red Bluff Rd., 13 / VI / 2007, 03 / VII / 2010, J. Sandberg, ♂ ♀; Sacramento Co., Cosumnes River, Michigan Bar, 23 / IV / 1982, R. Bottorff, Exuviae (NMNH); Cosumnes River, Michigan Bar, 18 / IV / 1986, R. Bottorff, ♂ ♀ damaged (NMNH); Siskiyou Co., McCloud River, Middle Falls near Fowlers Campground, 5.5 mi (8.8 km) E McCloud (Hwy 89), 13 / V / 2007, J. Sandberg, D. Pickard, ♂; Tehama Co., Big Chico Creek, Hwy 32 bridge, 2.3 mi (3.7 km) N of Lomo & Humboldt Rd. intersection, 06 / I / 2007, J. Sandberg, A. Richards, Larva; 03 / IV / 2010, J. Sandberg, Larvae (reared dark variant); Pine Creek, Wurlitzer Ranch, Barber Rd., 1.5 mi (2.4 km) E Meridian Rd. intersection, 07 / III / 2007, 03 / III / 2008, 03 / III / 2010, J. Sandberg, D. Pickard, Larvae (reared); SF Calf Creek, Hwy 32 crossing, 2.75 mi (4.4 km) S Potato Patch Campground, 26 / IV / 2010, R. Baumann, B. Kondratieff, A. Richards, J. Sandberg, J. Slusark, Larvae (reared); Trinity Co., SF Trinity River, Hwy 36, Forest Glen Campground, Forest Glen, J. Sandberg, 22 / V / 2008, Exuviae. OREGON: Benton Co., Rock Creek, 4 mi (6.4 km) W Philomath, 27 / IV / 1963, T. Schuh, ♀ (NMNH); Clatsop Co., Nehalem River, at Red Bluff Rd., 4 mi (6.4 km) NE Elsie, 17 - 18 / IV / 1965, S. Jewett Jr., ♂ (NMNH); Columbia Co., Scappoose Creek,? location, 08 / V / 1948, S. Jewett Jr., ♀ (NMNH); Jackson Co,. Squaw Lake,? location, 22 / V / 1964, J. Schuh, ♂ (NMNH); Linn Co., Stream near CAP. III, Monument Peak, 16 / VII / 1960,? collector, ♀ (NMNH).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8AF10FFF7CFBC391B7FDC6.taxon	description	Male larva. Body length of mature larva 11 – 13 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus indistinct, connected (sometimes partially) to light frontoclypeus area by a wide median longitudinal light band, lateral thin arms directed posterolaterally, extending to antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area variable, usually partially light, completely enclosed by dark pigment and not extending past posterior ocelli; occiput with irregular spinulae band extending from below eye to near median epicranial suture, not enclosed completely by dark pigment (Fig. 10 a). Lacinia bidentate, total length 816 – 974 µm (Figs. 2 h, 10 a-h, Tables 2 - 4); submarginal row (A + B) with 2 – 3 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 10 g); 1 submarginal seta (A) inserted at base of apical tooth (AT) inner margin, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT, submarginal seta (A) or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT or submarginal setae (B) (Figs. 10 g-h); 1 – 2 submarginal setae (B) located past SAT inner margin (Fig. 10 h); 7 – 10 marginal setae (C), initially long-stout and widely spaced, last few shorter and variably spaced, blending into and difficult to differentiate from dorsal and ventral surface setae (Fig. 10 e); 72 – 110 ventral surface setae (D) forming dense longitudinal band below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, setae closest to inner margin protrude laterally past lacinia margin (Fig. 10 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending before posterior-most ventral surface setae (Fig. 10 f). Galea with 19 – 40 setae in sparse ventral row, apex with 4 – 5 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with median light area bordered by wide dark bands typical of the I. marmorata complex; discs each with light rugosites concentrated along median dark margins and fine dark clothing setae, lateral margins with broad light bands (Fig. 10 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 10 c). Legs with numerous fine golden clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated on dorsal surface; fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 h); tibia with faint transverse bands near proximal end. Abdominal terga variable, usually with two distinct longitudinal dark stripes; wide light median longitudinal band sometimes bisected with faint, light brown longitudinal stripe; lateral pair of dark longitudinal stripes usually not extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 10 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8AF10FFF7CFBC391B7FDC6.taxon	distribution	Distribution. California, Nevada, Oregon, and Washington. In northern California, this species was found in small to medium sized creeks and rivers at a variety of elevations. It occurred with I. acula, I. mormona, Isoperla pinta Frison, Isoperla quinquepunctata (Banks), and I. roguensis.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8AF10FFF7CFBC391B7FDC6.taxon	diagnosis	Diagnosis. Male larvae of the I. marmorata complex were differentiated from other species with 1 – 2 lacinia submarginal (A) setae by having 41 – 110 ventral surface setae and pronotal discs mostly dark. Within the complex, I. marmorata was distinguished from I. roguensis by usually having the light M shaped pattern connected to the light anterior frontoclypeus area by a light longitudinal band (See also diagnosis under I. fulva). The only exception to the light M shaped pattern character occurred in 8 exuviae collected from Prairie Creek, Humboldt County, California. These possessed partial to entire M shaped light patterns, but were not connected to the light anterior frontal clypeus area.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8AF10FFF7CFBC391B7FDC6.taxon	discussion	Remarks. In Big Chico Creek, this species was collected at 82.9 m elevation, at Five-mile Recreation Area, Chico, and at 1043.9 m elevation at the Hwy 32 crossing, 45.1 km north of Chico. The adults of these two locations had different pigment patterns; the low elevation population was lighter than the high elevation darker population. A black adult I. marmorata variant has also been collected from Prairie Creek, Humboldt County (J. J. Lee, pers. com.). These “ dark and black ” variant color morphs have been suggested to be either ecophenotypes or cryptic sibling species within I. marmorata and more studies are needed to address this observation. Emergence occurred in April – May and the black Prairie Creek, Humboldt County population began its emergence in March (J. J. Lee, pers. com.).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8FF131FE9BFD92915CF9B7.taxon	description	(Figs. 2 i, 11 a-h, 20 i)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8FF131FE9BFD92915CF9B7.taxon	materials_examined	Material examined. TYPES: I. miwok, Holotype ♂, Allotype ♀, CA: El Dorado Co., 3.3 km NE Michigan Bar bridge, 5.3 km SW Latrobe, Indian Creek, 13 / IV / 1987, R. L. Bottorff (NMNH # 104427). Additional Specimens. CALIFORNIA: Butte Co., Campbell Creek & tributary, North Table Mountain Wildlife Area, Cherokee Rd, 5 mi (8 km) S Cherokee, 09 / II / 2007, 17 / II / 2007, J. Sandberg, Larvae; 03 / III / 2007, J. Sandberg, A. Richards, Larvae; 07 / IV / 2007, 13 / IV / 2007, J. Sandberg, ♀, Larvae (reared); 18 / IV / 2007, J. Sandberg, ♂; 02 / II / 2008, 09 / II / 2008, J. Sandberg, Larvae; 23 / II / 2008, J. Sandberg, D. Pickard, Larvae; 08 / III / 2008, 17 / III / 2008, 24 / III / 2008, 30 / III / 2008, J. Sandberg, Larvae (reared); Campbell Creek & tributary, North Table Mountain Wildlife Area, Cherokee Rd, 5.6 mi (9 km) S Cherokee, 5 - 6 / IV / 2008, J. Sandberg, ♂ ♀; 08 / IV / 2008, J. Sandberg, Larvae; 27 / IV / 2010, R. Baumann, B. Kondratieff, J. Sandberg, ♂; 02 / V / 2010, J. Sandberg, A. Richards, ♂ ♀, Larvae; 12 / III / 2011, J. Sandberg, ♂, Larvae (reared); 27 / III / 2011, J. Sandberg, Larvae (reared); Oregon Gulch, Red Bridge at Oregon Gulch Road, Oregon City, 16 / III / 2008, 22 / III / 2008, J. Sandberg, Larvae; 27 / IV / 2010, R. Baumann, B. Kondratieff, J. Sandberg, ♂ ♀; 02 / V / 2010, J. Sandberg, A. Richards, ♂ ♀, Larvae (reared); El Dorado Co., Tributary of NF Cosumnes River, Union Mine Rd., 3.4 mi (5.5 km) N Nashville at McNulty Mine Rd. crossing, 04 / IV / 2009, J. Sandberg, D. Pickard, Larvae; 25 / IV / 2009, J. Sandberg, Larvae (reared); Lake Co.,?, S junction Hwy 20 & 53, 22 / IV / 1955, S. Hitchcock, Larvae (lacinia mounted – Slide # 007) (NMNH).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8FF131FE9BFD92915CF9B7.taxon	description	Male larva. Body length of mature larva 9 – 11 mm. Dorsum of head with contrasting pigment pattern and fine light clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus variable, usually connected to light frontoclypeus area by an apically narrowed median longitudinal light band, lateral thin arms directed posterolaterally, extending to antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area variable, usually partially light, completely enclosed by dark pigment and extending posteriorly to epicranial Y-suture or sometimes open posteriorly and connected to posterior margin of head by thin light longitudinal band; occiput with irregular spinulae band extending from below eye to near median epicranial suture, not enclosed completely by dark pigment (Fig. 11 a). Lacinia bidentate, total length 622 – 888 µm (Figs. 2 i, 11 e- h, Table 2 - 4); submarginal row (A + B) with 2 – 3 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 11 g); 1 submarginal seta (A) inserted near mid-base of SAT, half as stout at its base as first submarginal (B) seta, plus 1 thin marginal seta (TMS) adjacent to apical tooth (AT) inner margin, sometimes obstructed from view by AT or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT (Figs. 11 g-h); 1 – 2 submarginal setae (B) located past SAT inner margin (Fig. 11 h); 5 – 7 marginal setae (C), initially long-stout and widely spaced, last few shorter and closer, blending into and difficult to differentiate from dorsal surface setae (Fig. 11 e); 7 – 15 ventral surface setae (D), scattered below marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length and concentrated in posterior half (Fig. 11 f); dorsal surface setae (DSS) continue from last marginal setae (C) as a single, laterally protruding, submarginal row (sometimes 2 – 3 setae thick) along inner-lateral margin, ending before or near posterior-most ventral surface setae (Fig. 11 f); 10 – 15 minute scale-like spinulae rarely present on and along ventral inner-lateral margin at middle of lacinia. Galea with 12 – 26 setae in sparse ventral row, apex with 2 – 4 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with large median light area bordered by thick dark comma shaped bands (typical of the I. sobria complex) that fade rapidly in alcohol; discs each with fine light clothing setae, except over small light rugosites and lateral margins with broad light bands (Fig. 11 b); Meso and metanotum with contrasting pigment pattern and fine light clothing setae (Fig. 11 c). Legs with numerous fine light clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated along dorsal surface; fine silky setae numerous and continuous on dorsal surfaces of femora and tibia (Fig. 20 i); distal femora and proximal tibia with faint transverse bands. Abdominal terga with three distinct longitudinal dark stripes; wide median longitudinal light band bisected with thin dark median longitudinal stripe; lateral pair of dark longitudinal stripes about as wide as median dark stripe, not extending to lateral margins; numerous fine light clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 11 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8FF131FE9BFD92915CF9B7.taxon	distribution	Distribution. California: usually non-perennial central Sierra Nevada foothill creeks.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8FF131FE9BFD92915CF9B7.taxon	diagnosis	Diagnosis. Male larvae of I. miwok are distinctive among all other California Isoperla species with 2 – 4 total submarginal (A + B) setae by the single lacinia submarginal (A) seta arising from near the middle of the base of the subapical tooth (Fig. 11 h).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FF8FF131FE9BFD92915CF9B7.taxon	discussion	Remarks. Isoperla miwok has long antennae and cerci as noted by Bottorff et al. (1990) which often break when collected and pigment patterns that darken or fade when preserved in ethanol. This species was collected with and emerged slightly before I. adunca from non-perennial foothill streams usually containing submerged aquatic plants. In Campbell Creek, Butte County, a large population seems to tolerate the increased organic enrichments supplied by ranging cattle and medium levels of stream bank erosion. Emergence occurred in late March – early May (late May in wetter years).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB1F132FEDBF94691CDFC13.taxon	description	(Figs. 2 j, 12 a-h, 20 j)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB1F132FEDBF94691CDFC13.taxon	materials_examined	Holotype ♀, Vinyard, Utah.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB1F132FEDBF94691CDFC13.taxon	materials_examined	Materials Examined. CALIFORNIA: Alameda Co.,?, Sunol Regional Park, 24 / IV / 1971, D. Denning, ♂ (NMNH); Indian Creek, 1.8 mi (2.9 km) upstream of San Antonio Reservoir, 25 - V- 2010, Larva (ABL); Butte Co., Big Chico Creek, Hooker Oak Recreation Area Chico, 10 / V / 1968, E. Evans, ♀ (NMNH); Big Chico Creek, Big Chico Creek Ecological Reserve, N 39.86909 W 121.70760, near north boundary, 24 / V / 2009, J. Sandberg, A. Richards, ♂ ♀, Larvae (reared); 25 / V / 2009, J. Sandberg, D. Pickard, Larvae; Big Chico Creek, Five-Mile Recreation Area, Centennial Ave & Crow Canyon Ct, Chico, (11, 15, 19) / V / 2010, J. Sandberg, ♂ ♀, Larvae (reared); Creek?, Richardson Springs, 11 / V / 1968, E. Evans, D. Maddox, ♂ (NMNH); Mud Creek, Richardson Springs, 15 / IV / 2010, J. Sandberg, D. Pickard, J. York, Larvae; El Dorado Co., Deadman Creek, Church Mine Road crossing, 2.45 mi (3.9 km) SE El Dorado, 23 / V / 2009, J. Sandberg, Larvae (1 ♂ reared); Greenwood Creek, Greenwood Creek Park, Hwy 49, 4 mi (6.4 km) E Pilot Hill, 16 / V / 2008, J. Sandberg, ♂ ♀; 28 / III / 2009, Larvae; 25 / IV / 2009, Larvae; 10 / V / 2009, ♀; 16 / V / 2009, 23 / V / 2009, ♂, Larvae (reared); NF Cosumnes River, Hwy 49 Nashville, 11 / VI / 1982, 13 - 19 / VI / 1982, R. Bottorff, ♂ ♀ (NMNH); NF Cosumnes River, Sweenys, Somerset, 23 / VI / 1952, R. Bottorff, ♀ (NMNH); Weber Creek, Forni Road bridge crossing Placerville, 16 / V / 2008, J. Sandberg, ♀; Inyo Co.,?, Sawmill, 3800 feet (1158 m), W Hwy 395, 15 / VII / 1965, A. Sheldon, ♂ ♀ (NMNH); Kern Co., Lucas Creek, Breckenridge Mt FR Rd, 5.7 mi S Hwy 178 nr Democrat Hot Springs, 10 / IV / 2008, Larvae (ABL); Los Angeles Co., Little Rock Creek, Cheseboro Rd (Forest Service Rd 5 N 04), 10.5 mi (16.9 km) S Littlerock, 03 / VI / 2010, Larvae (ABL); Marin Co.,?, Muir Woods, 27 / VI / 1965, D. Denning, ♂ ♀ (NMNH); Creek?, Near Point Reyes, 11 / V / 1971, D. Denning, ♂ (NMNH); Paper Mill Creek,? location, 06 / VI / 1965, S. Jewett Jr., ♀ (NMNH); Modoc Co.,?, 8 mi (12.9 km) NW Fandango Pass, Warner Mts, 11 / VII / 1967, Adult, E. Evans (NMNH); Thomas Creek, ~ 2.8 mi (4.5 km) below Hwy 299, 29 / VI / 2004, Larvae (ABL); Monterey Co., Big Sur River, Pfeiffer Big Sur State Park, 12 / VII / 1958, C. Alexander, ♀ (NMNH); Napa Co.,?, 7.6 mi (12.2 km) W Hwy 121 on Hwy 128, 20 / VI / 1985, C. & O. Flint Jr., Larvae (NMNH); Creek?, Near Glen Ellen, 18 / V / 1974, D. Denning, ♂ (NMNH); Plumas Co., Grizzly Creek, 2 mi (3.2 km) below Lake Davis Dam, 23 / V / 2006, J. Sandberg, D. Pickard, J. Slusark, ♂ ♀; Spanish Creek, Spanish Creek Campground, 3 mi (4.8 km) N of Keddie, 02 / VII / 2006, J. Sandberg, J., M., E., and S. Hartway, ♂ ♀, Exuviae; Spanish Creek, Chandler Road bridge, 13 / XI / 2007, Larvae (ABL); Sacramento Co., Cosumnes River, Sloughhouse, 31 / V / 1982, 14 / VI / 1982, R. Bottorff, ♀ (NMNH); Cosumnes River, Michigan Bar, 06 / VII / 1982, R. Bottorff, ♂ ♀ (NMNH); San Bernardino Co., Deep Creek, ~ 0.9 mi (1.4 km) above Crab Creek, 03 / VI / 2009, Larvae (ABL); Mill Creek, ~ 0.3 mi (0.5 km) W Mill Creek Campground, 15 / V / 2002, Larvae (ABL); SF Santa Ana River, E Barton Flats, 6200 feet (1890 m), San Bernardino Mts., 3 - 5 / VII / 1958, C. Alexander, ♂ ♀ (NMNH); San Mateo Co., Gazos Creek, Gazos Creek Road near Hwy 1, 10 / IV / 2007, Larvae (ABL); San Luis Obispo Co., San Simeon Creek, at San Simeon Creek Rd, 22 / IV / 2009, Larvae (ABL); Santa Cruz Co., San Lorenzo River, HC Redwoods State Park, Hwy 9, 0.5 mi (0.8 km) S Felton, 24 / V / 2007, J. Sandberg, Exuviae; Shasta Co.,?, Burney, 19 / VI / 1963, C. Quick, ♂ ♀ (NMNH); Burney Creek, ~ 1.7 mi (2.7 km) below Burney Falls, 16 / VI / 2004, Larvae (ABL); Sierra Co., Little Truckee River, Hwy 89 crossing, 12 mi (19.3 km) S of Sierraville, 21 / VII / 1950, C. Alexander, ♀ (NMNH); OREGON: Benton Co.,?, 9 mi (14.5 km) W Berry Creek Experimental Station, Corvallis, 07 / VI / 1968, E. Evans, ♂ (NMNH); Crook Co.,?, Ochoco Forest Campground nr Prineville, 26 / VII / 1963, J. Baker, ♀ (NMNH); Klamath Co.,?, Klamath Falls, Black Light, 15 / VII / 1971, J. Schuh, ♀ (NMNH); Umatilla Co., Umatilla River?, near Rieth, 05 / VII / 1948, C. Alexander, ♂ ♀ (NMNH); WASHINGTON: Yakima Co., Naches River, near Naches, 31 / VII / 1947, C. Alexander, ♀ damaged (NMNH).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB1F132FEDBF94691CDFC13.taxon	description	Male larva. Body length of mature larva 7 – 9 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus connected to light frontoclypeus area by a thin median longitudinal light band, lateral thin arms directed posterolaterally, extending to antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area variable, usually partially light, completely enclosed by dark pigment with light area extending to posterior margin of posterior ocelli, or sometimes mostly light and connected to posterior margin of head capsule by a thin median light band; occiput with irregular spinulae band extending from below eye to near median epicranial suture, not enclosed completely by dark pigment (Fig. 12 a). Lacinia bidentate, total length 525 – 666 µm (Figs. 2 j, 12 e-h, Tables 2 - 4); submarginal row (A + B) with 4 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 12 g); 1 submarginal seta (A) inserted at base of apical tooth (AT) inner margin, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT (Figs. 12 g-h); 3 submarginal setae (B) located past SAT inner margin (Fig. 12 h); 6 – 9 marginal setae (C), initially long-stout and widely spaced, last few shorter and widely spaced, blending into and difficult to differentiate from dorsal surface setae (Fig. 12 g); 7 – 14 ventral surface setae (D) scattered below marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length and concentrated in posterior half (Fig. 12 f); dorsal surface setae (DSS) continue from last marginal setae (C) as a single, laterally protruding, submarginal row (sometimes 2 – 3 setae thick) along inner-lateral margin, ending before posterior-most ventral surface setae (Fig. 12 f). Galea with 12 – 17 setae in sparse ventral row, apex with 2 – 3 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with median light area bordered (at least partially) by thin, irregular dark bands; discs each with partially enclosed light areas or “ windows ”, fine dark clothing setae and lateral margins with broad light bands (Fig. 12 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 12 c). Legs with numerous fine dark clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated on dorsal surfaces; fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 j); tibia with faint transverse bands near proximal end. Abdominal terga with three distinct longitudinal dark stripes; wide light median longitudinal band bisected with thin dark median longitudinal stripe; lateral pair of dark longitudinal stripes about as wide as median dark stripe, not extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 12 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB1F132FEDBF94691CDFC13.taxon	distribution	Distribution. Canada: British Columbia. USA: Arizona, California, Colorado, Idaho, Montana, New Mexico, Oregon, Utah, Washington, and Wyoming. Mexico: Baja California. Widely distributed throughout California.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB1F132FEDBF94691CDFC13.taxon	diagnosis	Diagnosis. Mature I. mormona male larvae are the smallest western Isoperla species (7 – 9 mm) and can be separated from other similar species that possess 2 – 4 submarginal setae (A + B) by having 7 – 14 ventral surface (D) setae (Fig. 12 f), fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 j) and interocellar area partially light (Fig. 12 a).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB1F132FEDBF94691CDFC13.taxon	discussion	Remarks. Isoperla mormona is distributed throughout northern and southern California from perennial and non-perennial streams. In Butte and El Dorado counties, emergence occurred in May – June.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB2F134FEA9FC2692F5FC86.taxon	description	(Figs. 2 k, 13 a-h, 20 k)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB2F134FEA9FC2692F5FC86.taxon	materials_examined	Material examined. TYPE: I. muir Holotype ♂, OR: Douglas Co., Hwy 230, downstream from bridge, Muir Creek, 12 / V / 2002, S. Szczytko, K. Stewart (reared with exuviae) (NMNH); Additional Specimens. OREGON: Douglas Co., Muir Creek, Muir Camp, Hwy 230 bridge, 13.5 mi (21.7 km) E Hwy 138 intersection, 27 / V / 2008, 31 / V / 2008, J. Sandberg, Larvae (reared).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB2F134FEA9FC2692F5FC86.taxon	description	Male larva. Body length of mature larva 9 – 13 mm. Dorsum of head with contrasting pigment pattern and a mixture of fine light and dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus thin and well defined, not connected to light frontoclypeus area, median longitudinal light band absent, lateral thin arms directed posterolaterally, extending to antennal bases; posterior ocelli with completely enclosed small light areas along outer lateral margins; interocellar area entirely dark; occiput with irregular spinulae band extending from below eye to near median epicranial suture, enclosed completely by dark pigment (Fig. 13 a). Lacinia bidentate, total length 724 – 837 µm (Figs. 2 k, 13 e- h, Tables 2 - 4); submarginal row (A + B) with 7 – 9 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 13 g); 2 submarginal setae (A) the first inserted at base of apical tooth (AT) inner margin, the second located between AT and SAT inner margins, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT, submarginal seta (A), or broken, dorsal seta (DS) absent (Figs 13 g-h); 5 – 7 submarginal setae (B) located past SAT inner margin (Fig. 13 g); 9 – 11 marginal setae (C), initially long-stout and widely spaced, first marginal setae located under flap-like SAT inner margin (Fig. 13 h – arrow), last few shorter and widely spaced (Fig. 13 e); 33 – 58 ventral surface setae (D) forming dense longitudinal band below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, setae closest to inner margin protrude laterally past lacinia margin (Fig. 13 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending at approximately the posterior-most ventral surface setae (Fig. 13 f). Galea with 22 – 32 setae in sparse ventral row, apex with 5 – 6 setae. Maxillary Palp segments 2 – 3 with nearly straight, apically rounded setae. Pronotum with thin indistinct median light line bordered by irregular dark longitudinal bands with adjacent light rugosites; discs each with brown comma shaped lateral areas, fine dark clothing setae and lateral margins without broad light bands (Fig. 13 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 13 c). Legs with numerous fine dark clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated on dorsal surfaces; fine silky setae absent on dorsal surface of femora, sparse on tibia (Fig. 20 k); tibia with very faint transverse bands near proximal end. Abdominal terga with two distinct longitudinal dark stripes; wide light median longitudinal band widest on middle segments, narrowing anteriorly and posteriorly; lateral pair of dark longitudinal stripes extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with distinct and scattered long, and numerous short spines in a concentrated row (Fig. 13 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB2F134FEA9FC2692F5FC86.taxon	distribution	Distribution. Oregon, known only from the type location (Szczytko & Stewart 2004) where it occurs with I. sobria.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB2F134FEA9FC2692F5FC86.taxon	diagnosis	Diagnosis. The mature male larvae of I. muir are most similar to I. adunca in that the submarginal row (A + B) setae form a continuous and regularly spaced row (Figs. 13 g-h). Isoperla muir can be separated from I. adunca by the submarginal setae row (A + B) regularly spaced at about the width of each seta base at points of insertion (Figs. 13 a, g-h), dorsal seta (DS) absent and first marginal seta (C) covered by flap-like subapical tooth inner margin base (Fig. 13 h).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB2F134FEA9FC2692F5FC86.taxon	discussion	Remarks. This distinctively pigmented species is rarely collected and is apparently restricted to the type locality. Limited rearing indicated emergence occurred in June.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB4F136FEE0FC5D9085FB9D.taxon	description	(Figs. 2 L, 14 a-h, 20 L)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB4F136FEE0FC5D9085FB9D.taxon	materials_examined	Holotype ♂, Floras Creek, Curry Co., Oregon.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB4F136FEE0FC5D9085FB9D.taxon	materials_examined	Material examined. CALIFORNIA: Butte Co., Butte Creek, Butte Creek Ecological Reserve, Honey Run Road, 2.9 mi (4.7 km) E intersection with Skyway, 13 / I / 2007, 05 / II / 2007, 11 / IX / 2007, J. Sandberg, Larvae; 17 / II / 2007, J. Sandberg, Larvae (reared), 04 / III / 2007, J. Sandberg, D. Pickard, ♂ ♀ Larvae (reared); 07 / IV / 2007, J. Sandberg, ♂ ♀; 18 / I / 2008, J. Sandberg, D. Pickard, Larvae; 04 / II / 2008, J. Sandberg, Larvae; 30 / III / 2008, ♂ ♀; 27 / III / 2009, ♂; 03 / IV / 2009, ♀; 19 / II / 2010, J. Sandberg, S. Hassur, Larvae (reared); 22 / II / 2010, J. Sandberg, Larvae (reared); 11 / III / 2010, J. Sandberg, J. York, Larvae (reared); 14 / III / 2010, J. Sandberg, Larvae (reared); 27 / IV / 2010, R. Baumann, B. Kondratieff, J. Sandberg, ♀; El Dorado Co., Cosumnes River, Michigan Bar, 18 / IV / 1986, R. Bottorff, ♂ ♀ (NMNH); Humboldt Co., Mad River, Arcata Bottoms, Mad River Road, N 40.91578 ° W 124.10618 °, 10 / IV / 2010, J. Sandberg, ♂ ♀; Monterey Co.,?, Carmel ,, E. VanDuzee, 23 / III / 1919, ♂ relaxed in KOH (NMNH); Plumas Co., Spanish Creek, Hwy 70 bridge, Quincy Town Park, 10 / III / 2007, J. Sandberg, Larva; Sacramento Co., Cosumnes River, Sloughhouse, 04 / IV / 1982, 25 / V / 1982, R. Bottorff, ♀ (NMNH); Tulare Co., Lemon Creek, Near Los Angeles, 14 / IV / 1950, R. Usinger, ♂ ♀ (NMNH); OREGON: Benton Co.,?, Corvallis, 06 / IV / 1907, J. Bridwell, ♂ (NMNH); Clatsop Co., Nehalem River, at Red Bluff Road 4 mi (6.4 km) NE Elsie, 17 - 18 / IV / 1965, S. Jewett Jr., ♀ (NMNH); Curry Co., Rogue River, Orchard Bar, Cty Hwy 595 (Agness Rd), 8.9 mi (14.3 km) NE Hwy 101, 14 / II / 2010, J. Sandberg, ♀, Exuviae; Rogue River, Coyote Bar, Cty Hwy 595 (Agness Rd), 5.6 mi (9.0 km) NE Hwy 101, 27 / II / 2010, J. Sandberg, Larvae; Douglas Co., Cow Creek, at Quines Creek, 08 / IV / 1968, S. Jewett Jr., ♀ (NMNH); Josephine Co?., Applegate River, Location?, 23 / II / 1968, S. Jewett Jr., ♀ (NMNH); Marion Co., Santiam River, Near Jefferson, 11 / IV / 1967, S. Jewett Jr., ♀ (NMNH). Santiam River, Boat Launch & Rest Stop, I- 5 bridge, 17 mi (27.3 km) S Salem, 19 / III / 2007, J. Sandberg, D. Pickard, J. Slusark, ♂.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB4F136FEE0FC5D9085FB9D.taxon	description	Male larva. Body length of mature larva 10 – 13 mm. Dorsum of head with contrasting pigment pattern and fine light and dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus not typical of western Isoperla species, usually connected to light frontoclypeus area by thin median longitudinal light band, lateral arms distinctly swollen at approximately mid length, usually directed laterally, extending to above antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area partially light, an irregular shape enclosed by dark brown pigment anteriorly and light brown pigment posteriorly; occiput with irregular spinulae band extending from below eye to near median epicranial suture, not enclosed completely by dark pigment (Fig. 14 a). Lacinia bidentate, total length 682 – 841 µm (Figs. 2 L, 14 e-h, Tables 2 - 4); submarginal row (A + B) with 4 – 5 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Figs. 14 g-h); 1 – 2 submarginal setae (A) the first inserted at base of apical tooth (AT) inner margin, the second when present, located between AT and SAT inner margins, first seta half as stout at base as marginal setae (C) and longitudinal striations weak or absent, all other species first seta nearly as stout and with striations, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT or first submarginal setae (B) (Figs. 14 g-h); 2 – 3 submarginal setae (B) located past SAT inner margin (Fig. 14 h); 4 – 7 marginal setae (C), initially long-stout and widely spaced, last few shorter and variably spaced, blending into and difficult to differentiate from dorsal setae (Fig. 14 e); 29 – 50 ventral surface setae (D) forming dense longitudinal band below marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, and concentrated in posterior half (Fig. 14 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending before posterior-most ventral surface setae (Fig. 14 f). Galea with 8 – 17 setae in sparse ventral row, apex with 4 setae. Maxillary Palp segments 2 – 3 with curved, apically rounded setae. Pronotum with irregular shaped median light area bordered by complex pattern of dark markings; discs each with distinctive lateral dark checkerboard pattern, fine dark and light clothing setae and lateral margins with broad light bands (Fig. 14 b). Meso and metanotum with contrasting pigment pattern and fine dark and light clothing setae (Fig. 14 c). Legs with numerous light and dark clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated along dorsal surface; fine silky setae numerous and continuous on dorsal surfaces of femora and tibia (Fig. 20 L); distal femur and proximal tibia with transverse bands. Abdominal terga with three distinct longitudinal stripes and small dark spots arranged in pairs on dorsal surface and in triplets laterally; wide light median longitudinal band bisected with irregular shaped dark median stripe; lateral pair of dark longitudinal stripes about as wide as median dark stripe, not extending to lateral margins; numerous fine light clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 14 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB4F136FEE0FC5D9085FB9D.taxon	distribution	Distribution. Canada: British Columbia, Alberta; USA: California, Colorado, Idaho, Montana, Oregon, Utah, Washington, and Wyoming. Mexico: Baja California. Widely distributed throughout northern California.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB4F136FEE0FC5D9085FB9D.taxon	diagnosis	Diagnosis. The male larvae of I. pinta are distinct among other western Isoperla species with 2 – 4 submarginal setae (A + B). The 1 – 2 submarginal setae (A) are less than half as stout at their base than the largest marginal setae (C) and lack or possess weak longitudinal striations (Figs. 14 g-h).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB4F136FEE0FC5D9085FB9D.taxon	discussion	Remarks. The distinctive head and pronotal pigment pattern of larvae could be used alone to identify individuals of this species in California, where Isoperla phalerata Needham has not been collected. In Butte Creek, Butte County, it was the first of three Isoperla species to emerge in March – April. Specimens examined in this study were compared with I. phalerata from previous drumming studies (Sandberg 2011, Sandberg & Stewart 2006), and the adults, larvae and drumming characters could not be separated. Perhaps these are sibling species and can only be separated by very slight aedeagus character differences or Scanning Electron Microscope characters of the ovum (Szczytko & Stewart 1979 – Figs. 64 - 71). However, it seems likely the Colorado I. phalerata population studied in Sandberg & Stewart (2006) was actually I. pinta. Further study is needed to confirm the identity of these two very closely related species.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB6F13BFC25FB559063FC13.taxon	description	(Figs. 2 m, 15 a-h, 20 m)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB6F13BFC25FB559063FC13.taxon	materials_examined	Holotype ♀.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB6F13BFC25FB559063FC13.taxon	materials_examined	Material examined. CALIFORNIA: Butte Co., Butte Creek, Butte Creek Ecological Reserve, Honey Run Road, 2.9 mi (4.7 km) E intersection with Skyway, 07 / IV / 2007, J. Sandberg, ♂; 11 / V / 2007, J. Sandberg, S. Hassur, ♂, Larvae; 03 / IV / 2009, J. Sandberg, Larvae; 14 / III / 2010, J. Sandberg, Larvae; 27 / IV / 2010, R. Baumann, B. Kondratieff, J. Sandberg, ♂; Butte Creek, Hwy 99 bridge, Chico, 11 / V / 2007, J. Sandberg, S. Hassur, ♀; El Dorado Co., NF Cosumnes River, Sweeney’s, Somerset, 13 - 21 / VI / 1982, R. Bottorff, ♀ (NMNH); NF Cosumnes River, Hwy 49, Nashville, 01 / VI / 1981, R. Bottorff, ♀ (NMNH); Napa Co., Capell Creek, 2.1 mi (3.4 km) W Rt 121 on Rt 128, 20 / VI / 1985, O. Flint, ♂ ♀ (NMNH); Placer Co., Truckee River, Rt 89, 9 mi (14.5 km) S I- 80, 5000 feet (1524 m), 19 / VI / 1985, C. & O. Flint, ♂ ♀ (NMNH); Sacramento Co., Cosumnes River, Michigan Bar, 23 / IV / 1982, 30 / IV / 1982, 06 / VII / 1982, 30 / III / 1984, 29 / IV / 1986, R. Bottorff, ♂ ♀ (NMNH); Cosumnes River, Sloughhouse, 04 / IV / 1982, 13 / V / 1982, 25 / V / 1982, 14 / VI / 1982, R. Bottorff, ♂ ♀ (NMNH); Tehama Co., Sacramento River, Near Red Bluff, 31 / III / 1965, S. Jewett Jr., ♂ (NMNH); Tulare Co., Kaweah River?, Near Three Rivers, 14 / V / 1964, D. Denning, ♂ ♀ (NMNH); Yuba Co., Yuba River, Hammon Grove Park, Hwy 22, 13 mi (20.9 km) NE Marysville, 07 / V / 2010, J. Sandberg, ♂ ♀, Larvae (reared); Yuba River, Hwy 22 bridge crossing, 16.4 mi (26.4 km) NE Marysville, 02 / V / 2010, J. Sandberg, A. Richards, ♂ ♀, Larvae (reared); 07 / V / 2010, J. Sandberg, ♂ ♀, Larvae (reared); OREGON: Baker Co.,?, Sumpter, on willow, 19 / VII / 1971, J. Baker, ♂ (NMNH); Clatsop Co., Nehalem River, at Red Bluff Rd., 4 mi (6.4 km) NE Elsie, 08 / V / 1965, S. Jewett Jr., ♀ (NMNH); Grant Co.,?, Ritter, 18 / VII / 1962, Clarke, ♂ ♀ (NMNH); Klamath Co?.,?, Odell Lake, Cascade Mts, 4760 feet (1451 m), 16 / VII / 1948, C. Alexander, ♂ ♀ (NMNH).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB6F13BFC25FB559063FC13.taxon	description	Male larva. Body length of mature larva 9 – 12 mm. Dorsum of head with contrasting pigment pattern and a mixture of fine light and dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus usually indistinct, not connected to light frontoclypeus area, median light longitudinal light band absent, lateral thin arms faint, directed posterolaterally, extending to antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area partially light and variable, either completely enclosed by dark pigment and entirely within the triangle, enclosed by dark pigment and extended posteromedially past posterior ocelli, or connected to posterior margin of head by thin longitudinal light pigment band; occiput with irregular spinulae band extending from below eye to near median epicranial suture, not enclosed completely by dark pigment (Fig. 15 a). Lacinia bidentate, total length 696 – 828 µm (Figs. 2 m, 15 e- h, Tables 2 - 4); submarginal row (A + B) with 3 – 4 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Figs. 15 g-h); 1 submarginal seta (A) inserted at the base apical tooth (AT) inner margin, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT (Figs. 15 g-h); 2 – 3 submarginal setae (B) located past SAT inner margin (Fig. 15 h); 7 – 11 marginal setae (C), initially long-stout and widely spaced, last few shorter and widely spaced, blending into and difficult to differentiate from dorsal and ventral surface setae (Fig. 15 e); 48 – 97 ventral surface setae (D) forming dense longitudinal band below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, setae closest to inner margin protrude laterally past lacinia margin (Fig. 15 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending before posterior-most ventral surface setae (Fig. 15 f). Galea with 23 – 27 setae in sparse ventral row, apex with 5 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with median light area occasionally with a short central indistinct brown band bordered by irregular dark pigment markings; discs each with partially to completely enclosed light areas, the largest resembling the “ windows ” described for I. acula, fine dark clothing setae and lateral margins with broad light bands (Fig. 15 b). Meso and metanotum with contrasting pigment pattern and fine light and dark clothing setae, dark setae enclosed by dark pigment (Fig. 15 c). Legs with numerous fine light clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated on dorsal surfaces; fine silky setae numerous and continuous on dorsal surfaces of femora and tibia (Fig. 20 m); tibia with at most, a very faint and incomplete band near joint with femora; femora with median, longitudinal light brown pigment band concentrated distally. Abdominal terga with three distinct longitudinal dark stripes; wide light median longitudinal band bisected with variable, thin to thick, dark median longitudinal stripe; lateral pair of dark longitudinal stripes about twice as wide as median dark stripe, nearly extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 15 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB6F13BFC25FB559063FC13.taxon	distribution	Distribution. Canada: Alberta, British Columbia and Saskatchewan; USA: California, Colorado, Idaho, Kansas, Montana, Nebraska, New Mexico, Nevada, Oregon, South Dakota, Utah, and Wyoming; Mexico: Baja California. Widely distributed throughout California.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB6F13BFC25FB559063FC13.taxon	diagnosis	Diagnosis. Mature male I. quinquepunctata larval pigment patterns are most similar to I. acula, I. mormona and I. sordida (Figs. 3 a-d, 12 a-d, 15 a-d, 18 a- d). In California, this species can be differentiated from other species with 1 – 4 submarginal setae (A + B) by having 48 – 97 ventral surface (D) setae (Figs. 15 eh), pronotal discs patterned with small to large central light areas, when large these areas not completely enclosed by dark pigment (Fig. 15 b).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFB6F13BFC25FB559063FC13.taxon	discussion	Remarks. When live, larvae of this species possess a distinctive red hue on non-sclerotized membrane. This species was found in large creeks and medium rivers with fast currents and with one or more of the following species: I. pinta, I. mormona, I. marmorata, and I. roguensis. Emergence occurred in May – June.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBBF13CFE85FC23924BFE93.taxon	description	(Figs. 2 n, 16 a-h, 20 n)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBBF13CFE85FC23924BFE93.taxon	materials_examined	Material examined. TYPES: I. roguensis, Holotype ♂, Allotype ♀, OR: Curry Co., Mouth of the Rogue River, 30 / III / 1949, S. Jewett Jr. (NMNH # 10469). Paratype ♂ (2 of 3 cleared with KOH), same as Holotype (Stan Szczytko Collection – University of Wisconsin-Stevens Point). Additional Specimens. CALIFORNIA: Butte Co., Butte Creek, Butte Creek Ecological Preserve, Honey Run Road, 2.9 mi (4.7 km) E of intersection with Skyway, 13 / I / 2007, 05 / II / 2007, J. Sandberg, Larvae; 04 / III / 2007, J. Sandberg, D. Pickard, Larvae (reared); 07 / IV / 2007, J. Sandberg, ♂ ♀, Larvae (reared); 13 / IV / 2007, J. Sandberg, ♂ ♀; 18 / I / 2008, J. Sandberg, D. Pickard, Larvae; 30 / III / 2008, J. Sandberg, ♂ ♀, Larvae; 30 / IV / 2008, J. Sandberg, ♀; 27 / III / 2009, J. Sandberg, Larvae; 03 / IV / 2009, J. Sandberg, ♂ ♀; 19 / II / 2010, J. Sandberg, S. Hassur, Larvae; 22 / II / 2010, J. Sandberg, Larvae (reared); 11 / III / 2010, J. Sandberg, J. York, Larvae (reared); 14 / III / 2010, J. Sandberg, Larvae (reared); Big Chico Creek, Big Chico Creek Ecological Reserve, N 39.86909 °, W 121.70760 °, near north boundary, 27 / IV / 2010, R. Baumann, B. Kondratieff, J. Sandberg, ♀; Big Chico Creek, Five-Mile Recreation Area, Centennial Ave & Crow Canyon Ct, Chico, 27 / III / 2010, J. Sandberg, ♂ ♀, Larvae (reared); Humboldt Co., Klamath River, Aikens Creek Campground, Hwy 96, 4.7 mi (7.6 km) NE Weitchpec, 09 / IV / 2010, J. Sandberg, ♂ ♀, exuviae; Mad River, Arcata Bottoms, Mad River Road, N 40.91578 °, W 124.10618 °, 10 / IV / 2010, J. Sandberg, ♂ ♀; Plumas Co., Spanish Creek, Spanish Creek Campground, 3 mi (4.8 km) N Keddie, 04 / III / 2007, J. Sandberg, D. Pickard, Larvae (reared); Tehama Co., Mill Creek, 1000 ft (305 km) upstream of Sacramento River confluence, Elev. 208 ft (63.4 m), 13 / IV / 2011, J. Dittes. OREGON: Curry Co., Rogue River, Orchard Bar, Cty Hwy 595 (Agness Road), 8.9 mi (14.3 km) NE Hwy 101, J. Sandberg, Larvae (reared); 20 / III / 2010, J. Sandberg, ♀, Larvae (reared); Rogue River, Rotary Riverside Trail, Cty Hwy 595 (Jerry’s Flat Road), 0.35 mi (0.6 km) NE Hwy 101, 21 / III / 2010, J. Sandberg, ♀.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBBF13CFE85FC23924BFE93.taxon	description	Male larva. Body length of mature larva 9 – 12 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus variable, usually indistinct, not connected to light frontoclypeus area and completely enclosed in dark pigment, median longitudinal light band absent, lateral thin arms faint, lacking clothing setae, directed posterolaterally and extending to antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area variable, from completely dark to partially light, when small light area present, completely enclosed by dark pigment and not extending posteriorly past posterior ocelli; occiput with irregular spinulae band extending from below eye to near median epicranial suture, not enclosed completely by dark pigment (Fig. 16 a). Lacinia bidentate, total length 682 – 862 µm (Figs. 2 n, 16 e- h, Tables 2 - 4); submarginal row (A + B) with 3 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 16 g); 1 submarginal seta (A) inserted at base of apical tooth (AT) inner margin, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT, submarginal seta (A) or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT or submarginal setae (B) (Figs. 16 g-h); 2 submarginal setae (B) located past SAT inner margin (Fig. 16 h); 5 – 9 marginal setae (C), initially long-stout and widely spaced, last few shorter and widely spaced, blending into and difficult to differentiate from dorsal and ventral surface setae (Fig. 16 e); 48 – 88 ventral surface setae (D) forming dense longitudinal band below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, setae closest to inner margin protrude laterally past lacinia margin (Fig. 16 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending before posterior-most ventral surface setae (Fig. 16 f). Galea with 19 – 27 setae in sparse ventral row, apex with 4 – 6 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with median light area occasionally with a thin central indistinct brown band bordered by wide dark irregular pigment bands typical of the I. marmorata group; discs each with variable and irregular inner lateral dark pigment margins, variable light rugosites usually concentrated along inner dark band margins, fine dark clothing setae except over rugosites and lateral margins with broad light bands (Fig. 16 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 16 c). Legs with numerous fine golden to light brown clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated on dorsal surface; fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 n); tibia with extremely faint transverse bands near proximal end. Abdominal terga variable, usually with two distinct longitudinal dark stripes; wide light median longitudinal band sometimes bisected by faint, light brown longitudinal median band; lateral pair of dark longitudinal stripes usually not extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 16 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBBF13CFE85FC23924BFE93.taxon	distribution	Distribution. California, Oregon. Widely distributed in northern California.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBBF13CFE85FC23924BFE93.taxon	diagnosis	Diagnosis. Mature male larvae of I. roguensis are most similar to I. fulva and I. marmorata. The larvae of this species can not be separated from I. fulva but can be distinguished from I. marmorata by the lack of or reduced M shaped light pattern not connected to unpigmented frontoclypeus (Fig. 16 a). Pigment patterns are known to vary in Isoperla and a nonpigment character must be found before increased species resolution can be achieved in the I. marmorata complex.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBBF13CFE85FC23924BFE93.taxon	discussion	Remarks. The three western species included in the I. marmorata complex have similar dark larval pigment patterns. In several locations, I. roguensis was found with one or more of the following: I. marmorata, I. mormona, I. pinta or I. quinquepunctata. Emergence was slightly extended and occurred in March – May. Isoperla karuk is placed as a new junior subjective synonym of I. roguensis based upon comparison with reared material from the type localities, additional California locations and comparison of the aedeagii with the everted and cleared I. roguensis paratypes held in the collection of Dr. Stanley Szczytko, University of Wisconsin-Stevens Point. The authors of I. karuk (Richard Baumann, Per. com) based their description upon an everted aedeagus of a live adult (Bauman & Lee 2009 - Figs. 17 - 24) which seemed different from the hyper everted and cleared aedeagus of an already preserved adult in Szczytko & Stewart (1984 – Fig. 55). An important consideration for future adult taxonomy of this genus is that no two live adult males can be everted to the same extent. The adult male aedeagus is a thin membranous inverted sac, that when squeezed out of the posterior ninth sternal inter-segmental membrane (evertion), is filled with seminal fluid (like a balloon). The consistent evertion of lobes and placement of diagnostic setae patches or sclerotized posterior processes are confounded by 1) the amount and length of time of evertion (should take place under a dissecting microscope to ensure full evertion) and 2) whether the aedeagus was fixed in near boiling water. If less evertion pressure or no hot water fixation was used, the aedeagus will invert to some degree. The comparison of live everted versus preserved hyper everted males is further complicated by the clearing method used in Szczytko & Stewart (1979), which presumably allows internal lobes and lobe-like structures to become everted (See I. baumanni).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBCF121FEEBFEA79752FBF9.taxon	description	(Figs. 2 o, 17 a-h, 20 o)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBCF121FEEBFEA79752FBF9.taxon	materials_examined	Holotype ♀.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBCF121FEEBFEA79752FBF9.taxon	materials_examined	Material examined. ALASKA: Matanuska - Susitna Border, Montana Creek, Hwy 3 bridge near Montana, 08 / VI / 2006, J. Sandberg, J. Harrington, D. Pickard, J. Slusark, T. Morman, Female Exuviae; CALIFORNIA: Butte Co., Butte Creek, Cherry Hill Campground (Humboldt Rd) 9 mi (14.5 km) NE Lomo (Hwy 32), 06 / I / 2007, J. Sandberg, A. Richards, Larvae; 27 / I / 2007, J. Sandberg, Larva; 03 / II / 2007, J. Sandberg, A. Richards, Larva; 01 / IV / 2007, J. Sandberg, Larva; 20 / III / 2008, J. Sandberg, S. Sandberg, Larvae; 26 / IV / 2010, R. Baumann, B. Kondratieff, A. Richards, J. Sandberg, J. Slusark, ♂ (reared); Butte Creek, Humboldt Road bridge at Colby / Willow Creeks, 0.25 mi (0.4 km) W Jonesville, 25 / V / 2008, J. Sandberg, ♂; Colusa Co., Big Springs tributary, Big Springs Picnic Area, Letts Lake, FR 17 N 02, Mendocino NF, 03 / II / 2009, J. Sandberg, D. Pickard, Larvae; Lily Pond unmapped outflow, W Lily Pond FR 17 N 02 crossing, Mendocino NF, 03 / II / 2009, J. Sandberg, D. Pickard, Larvae; Little Stony Creek, FR 18 N 07, 20 mi SW Stonyford, Mendocino NF, 01 / II / 2009, J. Sandberg, A. Richards, Larvae; Contra Costa Co.,?, Martinez,? / VI / 1910, J. Grundell, ♂ cleared (NMNH); El Dorado Co., Tributary of NF Cosumnes River, above Meiss Ranch, 06 / VI / 1986, R. Bottorff, Female Larvae, Male Exuviae (mounted lacinia slide # 015) (NMNH); Rubicon River,? location, 05 / IX / 1954, S. Hitchcock, Larvae (NMNH); Mariposa Co., Tamarack Creek, Yosemite National Park, 6300 feet, 30 / V / 1955, S. Hitchcock, Larvae (mounted lacinia slide # 014) (NMNH); Nevada Co.,? spring, entering Sagehen Creek, 6400 feet, 05 / VI / 1965, A. Sheldon, Male Larvae (mounted lacinia slide # 013) (NMNH); Spring head of Hanging Bog, Sagehen Creek, 6300 feet, 23 / V / 1966, ♂, 13 / IX / 1965, A. Sheldon, ♂ ♀ (NMNH); Bog Spring, Sagehen Creek, 22 / VI / 1966, ♀; 07 / VII / 1966, A. Sheldon, ♂ (NMNH); Spring Trib, to Sagehen Creek, 30 / VI / 1965, ♂; 01 / VIII / 1965, ♂; 11 / VIII / 1965, ♂ ♀; 26 / VIII / 1965, ♀; 31 / VIII / 1965, ♂ ♀; 13 / IX / 1965, A. Sheldon, ♂ ♀ (NMNH); Sagehen Creek, Sagehen Creek Project, Spring Run, 6400 feet, 02 / VI / 1965, A. Sheldon, Female larvae (mounted lacinia slide # 0102) (NMNH); Sagehen Creek, 6400 feet, 05 / VI / 1965, Larvae; 24 / VI / 1965, A. Sheldon, ♂ ♀ (NMNH); Sagehen Creek, 6300 feet, 30 / V / 1965, ♀; 01 / VI / 1966, A. Sheldon, ♀ (NMNH); Sagehen Creek, Diversion, 02 / VI / 1966, ♂; 09 / VI / 1966, ♂; 11 / VII / 1966, A. Sheldon, ♀ (NMNH); Sagehen Creek, Station Spring, 25 / VII / 1966, A. Sheldon, ♂ (NMNH); Sagehen Creek,? location, 19 / VI / 1985, O. Flint, ♀, Larvae; Placer Co?,?, on Carnelian Bay, Lake Tahoe, 24 / VI / 1954, S. Hitchcock, ♂ ♀ (NMNH); Plumas Co., Big Grizzly Creek, 0.4 mi (0.6 km) S Beckwourth Rd on Unnamed Rd, 6 mi (9.6 km) E Lake Davis, 30 / VI / 2006, ♀ (Malaise Trap); 15 / XII / 2006, J. Sandberg, A. Richards, Larvae; Cow Creek, 2 mi (3.2 km) NE Smith Peak nr intersection with jeep trial, 21 / VI / 2006, larvae; 30 / VI / 2006, J. Sandberg, A. Richards, ♀ (Malaise Trap); Freeman Creek, 2 mi (3.21 km) S on Threemile Valley Rd, S Lake Davis, 21 / VI / 2006, Exuviae; 30 / VI / 2006, ♂ ♀ (Malaise Trap), J. Sandberg, A. Richards; Mosquito Creek (West Branch), 0.4 mi (0.6 km) E Domingo Springs, 8.1 mi (13.0 km) W of Chester, 04 / II / 2007, J. Sandberg, Larvae; 22 / IV / 2007, J. Sandberg, D. Pickard, Larvae (reared); 19 / V / 2007, J. Sandberg, S. Hassur, ♀, Larvae (reared); 28 / V / 2007, J. Sandberg, D. Pickard, ♀, Larvae (reared); 13 / VI / 2007, J. Sandberg, Larvae (reared); 16 / IX / 2007, J. Sandberg, Larvae; 03 / XI / 2007, J. Sandberg, Larvae; 17 / V / 2008, J. Sandberg, Larvae; 13 / VI / 2008, J. Sandberg, ♂ ♀, Larvae (reared); 20 / VI / 2008, J. Sandberg, ♂, Larvae (reared); 05 / VI / 2010, J. Sandberg, Larvae (reared); 03 / VII / 2010, J. Sandberg, ♂ ♀, Larvae (reared); Spring Trib of Lake Davis (Corral), Feeding SE Lake Davis on Threemile Valley Rd, 29 / V / 2006, J. Sandberg, D. Pickard, J. Slusark, Larvae (reared); 27 / X / 2006, J. Sandberg, A. Richards, Larvae; 06 / VI / 2010, J. Sandberg, J. Slusark, Larvae (reared); 04 / VII / 2010, J. Sandberg, ♂ ♀, Larvae (reared); Spring Trib of Lake Davis (Moselia), Feeding E Lake Davis, 0.5 mi (0.8 km) E Freeman Cr, 29 / V / 2006, J. Sandberg, D. Pickard, J. Slusark, ♀, Larvae; 21 / VI / 2006, J. Sandberg, A. Richards, Larvae; Sierra Co., Weber Lake, Little Truckee River?, Henness Pass Road, 04 / VII / 1965, P. Arnaud, ♀ (CAS); Shasta Co.,?, Burney Falls, 17 / IX / 1946, H. Chandler, ♀ (CAS); NF Battle Creek,? location, 04 / VII / 1953, H. Chandler, ♀ (CAS); Tehama Co., Gurnsey Creek, Gurnsey Creek Campground, Hwy 36 (89), 2.3 mi (3.7 km) N Hwy 32 intersection, 27 / I / 2007, J. Sandberg, Larva; Tulare Co.,?, Sequoia National Park, Giant Forest, 6400 feet, 19 / VI / 1963, C. Alexander, ♀ (NMNH); Tuolumne CO., Gaylor Lakes, Yosemite NP East, 1000 feet, 08 / VII / 1945, H. Chandler, ♀ (CAS); COLORADO:? County,? River, Longs Peak, 12 / VII / 1926, E. Vandyke, ♂ ♀ (CAS); IDAHO: Franklin Co.,?, Willow Flat Forest Camp, Cub River Canyon, Wasatch Mts, 4 - 5 / VII / 1952, B. Malkin, ♂ (CAS); OREGON: Baker Co., Pine Creek,? location, 26 / VI / 1948, J. Baker, ♀ (CAS); Benton Co., Oak Creek, Corvallis, 02 / IV / 1935, R. Dimick, ♂ cleared (NMNH); Oak Creek, 6.75 mi (10.9 km) NW Corvallis, Rt branch Oak Cr., E Patterson Rd., 1.5 mi (2.4 km) N of Fish lab, 700 feet, 16 - 19 / V / 1969, C. Kerst, ♂ (NMNH); 16 - 19 / V / 1969, C. Kerst, ♂ damaged (NMNH); Clackamas Co., Still Creek, Swim Cr., 15 / VI / 1947, S. Jewett Jr., ♀ (CAS); Coos Co., Wooden Rock Creek, Pioneer Campground, NFD 240 Rd, 0.2 mi (0.3 km) N NFD 3348 Rd intersection, 19 / III / 2010, J. Sandberg, Larvae; Deschutes Co., Fall River,? location, 13 / VII / 1948, S. Jewett Jr., ♂ ♀ (CAS); Fall River, Fall River Campground, Hwy 42 (S Century Dr), 13 mi (20.9 km) E Hwy 97, 28 / V / 2008, 31 / V / 2008, J. Sandberg, ♂ ♀, Exuviae, Larvae (reared); Douglas Co., Muir Creek, Muir Camp, Hwy 230 bridge, 13.5 mi (21.7 km) E Hwy 138 intersection, 27 / V / 2008, 31 / V / 2008, Larvae (reared); Grant Co?, Lunch Creek, Blue Mountains, 24 / VI / 1952, B. Malkin, ♀ (CAS); Hood River Co.?,?, Hood River Meadows, Mt Hood, 18 / VII / 1947, K. Fender, ♀ (CAS);? River, Hood River Meadows, E side of Hood, 4475 feet, 31 / VII / 1948, C. Alexander, ♀ (NMNH); Klamath Co., Spring Creek, Collier State Park, Hwy 97, 3.7 mi (5.9 km) N Pine Ridge, 12 / V / 1950, S. Jewett Jr., ♂ ♀ (CAS); Linn Co., Marion Creek, Marion Creek (Lake) Rd at Willis Creek confluence, 08 / VI / 2011, J. Sandberg, ♂ Exuviae; WASHINGTON: Cowlitz Co., Upper Kalama River,? location, 01 / XII / 1966, O. Flint, ♂ (NMNH); Pierce Co?, Nisqually River, Mt Rainier NP, 13 / VII / 1936, E. Vandyke, ♀ (CAS); Skamania Co. Tyee Spring, Meadow Creek Rd, 0.44 mi (0.71 km) N NFD 3065 & NFD 30 Rds, 16 / VI / 2011, J. Sandberg, ♂ ♀ Exuviae.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBCF121FEEBFEA79752FBF9.taxon	description	Male larva. Body length of mature larva 10 – 13 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus connected to light frontoclypeus area by a median longitudinal light band, its width approximately equal to the posteromedian portion of the light M shaped pattern, lateral arms with irregular margins usually disconnected from median light area, directed posterolaterally, and extending to antennal bases; posterior ocelli with partially enclosed large light areas along outer lateral margins; interocellar area variable, usually partially light and shaped like an inverted V, completely enclosed by dark pigment and not extending past posterior ocelli, sometimes a small spot; occiput with irregular spinulae band extending from below eye to near median epicranial suture, not enclosed completely by dark pigment (Fig. 17 a). Lacinia bidentate, total length 901 – 1265 µm (Figs. 2 o, 17 e- h, Tables 2 - 4); submarginal row (A + B) with 5 – 6 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 17 g); 3 – 4 submarginal setae (A) in a close set row beginning at base of apical tooth (AT), ending before reaching SAT inner margin, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT, submarginal setae (A), or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT; 2 submarginal setae (B) located past SAT inner margin (Figs. 17 g-h); 10 – 17 marginal setae (C), initially longstout and widely spaced, sometimes several setae near end of row arranged in pairs protruding at dorsal and ventral angles, last few shorter and closer, blending into and difficult to differentiate from dorsal surface setae (Fig. 17 e); 21 – 58 ventral surface setae (D) scattered below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, occasionally a few setae located below submarginal row striated (Fig. 17 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band, concentrated at junction with marginal setae (C), ending at approximately ½ or a little more the lacinia length (Fig. 17 e). Galea with 12 – 23 setae in sparse ventral row, apex with 2 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae (Inset, Fig. 17 e). Pronotum with large median light area bordered thick dark comma shaped bands typical of the I. sobria complex, a range of irregular shaped faded light brown areas usually present between the dark commas and entirely covered by fine dark clothing setae, lateral margins with broad light bands (Fig. 17 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 17 c). Legs with numerous fine golden clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated along dorsal surfaces; fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 o); distal femora and proximal tibia with distinct transverses bands. Abdominal terga with three distinct longitudinal dark stripes; wide light median band bisected with irregular shaped, dark median longitudinal stripe; lateral pair of dark longitudinal stripes about twice as wide as median dark stripe, usually not extending to lateral margins; numerous fine light clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 17 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBCF121FEEBFEA79752FBF9.taxon	distribution	Distribution. Canada: Alberta, British Columbia and Yukon territory; USA: Alaska, Arizona, California, Colorado, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington, and Wyoming. In northern California, widely distributed at higher elevations.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBCF121FEEBFEA79752FBF9.taxon	diagnosis	Diagnosis. Mature male larvae of I. sobria are distinctive with the following characters: the lacinia submarginal row (A) has 3 – 4 close set setae (Figs. 17 e, g-h), the completely enclosed inverted V shaped interocellar light area does not extend past posterior ocelli (Fig. 17 a), and basal segments 2 – 3 of the maxillary palpi have long, thin apically pointed setae (Fig. 17 a Inset). The interocellar light area was sometimes only a very small spot. It shares a similar dark comma shaped pronotal pigment pattern with the other species in the I. sobria complex (Figs. 5 b, 11 b, 17 b, 19 b). Only I. miwok lacked the multiple submarginal setae (A) character (Figs. 11 e, g-h).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFBCF121FEEBFEA79752FBF9.taxon	discussion	Remarks. The abdominal pigment stripes of some male and female larvae faded quickly in ethanol and the abdomen became completely dark, losing the light longitudinal stripes. Emergence was slightly extended and occurred in May – July. Adult females had slightly longer subgenital plates than what is illustrated (Fig. 89, Szczytko & Stewart 1979). The typical I. sobria subgenital plate had nearly parallel lateral margins, extended posteriorly to nearly the mid length of abdominal sternite nine, and the apical margin was broadly rounded. There were observations which may extend the ranges of submarginal lacinia setae, but could not be confirmed with reared and associated specimens. One I. sobria male larva from Williams Fork, Grand County, Colorado, four larvae from Rio Fernando de Taos, Taos County, New Mexico, and one exuviae from Tyee Spring, Skamania County, Washington, had two close set lacinia submarginal (A) setae. This character would overlap with the lower range observed for I. tilasqua (Table 2). Another male larva from Marion Creek, Linn County, Oregon, possessed 5 lacinia submarginal (A) setae, and two submarginal (B) setae. However, all the above male larvae were identified as I. sobria because they possessed long, thin, apically pointed setae on the maxillary palp basal segments 2 – 3 and inverted V shaped light interocellar marks.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA1F123FC65FB899087F88D.taxon	description	(Figs. 2 p, 18 a-h, 20 p)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA1F123FC65FB899087F88D.taxon	materials_examined	Holotype ♂, Los Angeles Co., CA, USA.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA1F123FC65FB899087F88D.taxon	materials_examined	Material examined. CALIFORNIA: Mono Co., Coldwater Creek, Coldwater Campground, Inyo National Forest, 9000 feet, 16 / VIII / 1959, C. Alexander, ♂ everted, ♀ (NMNH); Coldwater Campground, Inyo National Forest, 4.7 mi S Mammoth Lakes (Hwy 203), 26 / VII / 2010, J. Sandberg, Larvae (reared); 08 / VIII / 2010, ♂ ♀, Larvae (reared); 07 / IX / 2010, ♂ ♀; 09 / VIII / 2011, J. Harrington, A. Montalvo, J. Sandberg, Larvae; McKay Creek, ~ 3.6 mi above Sardine Creek, 31 / VI / 2008, Larvae (ABL); Nevada Co., Bog Spring – Sagehen Creek, Near Hobart Mills, 6300 feet, 14 / IX / 1965, A. Sheldon, ♀ (NMNH); San Bernardino Co.,?, Hurkey Creek Campground, San Jacinto Mts, 4300 feet, 01 / VII / 1958, C. Alexander, ♂ ♀ (poor condition) (NMNH); OREGON: Deschutes Co., Fall River, Fall River Campground, Hwy 42 (S Century Dr), 13 mi (20.9 km) E Hwy 97, 28 & 31 / V / 2008, J. Sandberg, ♂ ♀, Larvae (reared); Linn Co?, McKenzie River, Bridge near Clear Lake, 07 / X / 1965, S. Jewett Jr., ♀ (NMNH); WASHINGTON:? County,?, Silver Fir Camp, Mt Baker, 1800 feet, 13 / VIII / 1947, C. Alexander, ♂ (NMNH).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA1F123FC65FB899087F88D.taxon	description	Male larva. Body length of mature larva 11 – 13 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus indistinct, connected to light frontoclypeus area by a broad median longitudinal light band, lateral thin arms with nearly parallel margins connected to median light band, directed posterolaterally and extending to antennal bases; posterior ocelli usually with partially enclosed large light areas along outer lateral margins, occasionally light areas small and completely enclosed; interocellar area variable, from completely dark to partially light, completely enclosed by dark pigment and not extending past posterior ocelli; occiput with irregular spinulae band extending from below eye to near median epicranial suture, not enclosed completely by dark pigment (Fig. 18 a). Lacinia bidentate, total length 856 – 992 µm (Figs. 2 p, 18 e-h, Tables 2 - 4); submarginal row (A + B) with 3 – 4 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 18 g); 1 submarginal seta (A) located at base of apical tooth (AT) inner margin, plus 1 thin marginal seta (TMS) adjacent to AT inner margin sometimes obstructed from view by AT, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT or submarginal setae (B) (Figs. 18 g-h); 2 – 3 submarginal setae (B) located past SAT inner margin (Fig 18 h); 8 – 11 marginal setae (C), initially long-stout and widely spaced, last few shorter and closer, blending into and difficult to differentiate from dorsal surface setae (Fig. 18 e); 41 – 67 ventral surface setae (D) forming dense longitudinal band below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length, setae closest to inner margin protrude laterally past lacinia margin (Fig. 18 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending before posterior-most ventral surface setae (Fig. 18 f). Galea with 20 – 26 setae in sparse ventral row, apex with 2 – 5 setae. Maxillary Palp segments 2 – 3 with curved, apically pointed setae. Pronotum with light median area bordered by wide dark pigment bands, discs each with large, completely enclosed light areas or “ windows ”, fine dark clothing setae and lateral margins without broad light bands (Fig. 18 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 18 c). Legs with numerous fine dark clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated on dorsal surfaces; fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 p); tibia with faint transverse bands near proximal end. Abdominal terga variable, usually with two distinct longitudinal dark stripes; wide light median longitudinal band sometimes bisected with faint, light brown median longitudinal band; lateral pair of dark longitudinal stripes usually not extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 18 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA1F123FC65FB899087F88D.taxon	distribution	Distribution. Canada: Alberta, British Columbia; USA: Alaska, California, Idaho, Montana, Oregon, and Washington. Only recently confirmed in eastern slope Sierra Nevada streams at elevations greater than 1524 m.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA1F123FC65FB899087F88D.taxon	diagnosis	Diagnosis. Isoperla sordida male larvae are distinct among other western Isoperla species with 1 – 4 submarginal row (A) setae by having a lacinia with 41 - 67 ventral surface (D) setae (Figs. 18 e-f), pronotal discs with large distinct window like light areas (Fig. 18 b), and femora with a sparse row of silky setae (Fig. 20 p).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA1F123FC65FB899087F88D.taxon	discussion	Remarks. The type locality for this species is Los Angeles County, California, and is the only specimen of this species known from this county. In Oregon, emergence is in late spring to early summer. In California, emergence occurs in late summer to fall and distribution appears restricted to the eastern Sierra Nevada range high elevation spring fed or snow melt streams above 1524 m.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA2F124FE83FF35906CFB0F.taxon	description	(Figs. 2 q, 19 a-h, 20 q)	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA2F124FE83FF35906CFB0F.taxon	materials_examined	Material examined. TYPES: I. tilasqua Holotype ♂, Oregon: Benton Co., Oak Creek, 13 - 16 / VI / 1968,? collector (NMNH # 76346); Paratype ♀, Same as Holotype, 7 - 10 / VI / 1968; Additional Specimens. CALIFORNIA: Siskiyou Co., Sacramento River, Headwater, Mt. Shasta, 29 / V / 1967, S. G. Jewett Jr., ♀ (NMNH); OREGON: Benton Co., Oak Creek, Trap 2, 6.5 mi NW Corvallis, 1 mi N Fish Lab 650 feet, 19 - 22 / VI / 1968, C. Kerst, ♀ (looked more like I. sobria) (NMNH); Clackamas Co., Still Creek, Still Creek Campground, Mt Hood, 10 / VI / 1955, 17 / VI / 1967, S. G. Jewett Jr., ♀ (NMNH); Grant Co.,?, Trout Meadows, 5500 feet, 09 / VII / 1967, J. Baker, ♀ (NMNH); Umatilla Co., Meacham Creek, Upstream (west) of Hwy 84 bridge, 30 / V / 2008, 22 / V / 2011, J. Sandberg, Larvae (reared).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA2F124FE83FF35906CFB0F.taxon	description	Male larva. Body length of mature larva 10 – 11 mm. Dorsum of head with contrasting pigment pattern and fine dark clothing setae, anterior frontoclypeus margin unpigmented; light M shaped pattern anterior to median ocellus connected to light frontoclypeus area by a median longitudinal light band, its width approximately half the posteromedian portion of the light M shaped pattern, lateral thin arms with nearly parallel margins connected to median light band, directed posterolaterally and extending to antennal bases; posterior ocelli with completely enclosed medium sized light areas along outer lateral margins, extending laterally above epicranial suture in fresh specimens; in older preserved specimens, posterior light brown band becomes faded; interocellar area partially light, an irregular shaped light area connected to posterior head capsule by thin light band; occiput with irregular spinulae band extending from below eye to near median epicranial suture, usually enclosed completely by dark to light brown pigment (Fig. 19 a). Lacinia bidentate, total length 978 - 1012 µm (Figs. 2 q, 19 e- h, Tables 2 - 4); submarginal row (A + B) with 4 – 7 setae, groups A-B interrupted by gap below subapical tooth (SAT) inner margin (Fig. 19 g); 2 – 5 submarginal setae (A) in a close set row beginning at the base of the apical tooth (AT), ending before reaching SAT inner margin, plus 1 thin marginal seta (TMS) adjacent to AT inner margin, sometimes obstructed from view by AT, submarginal setae, or broken, and 1 dorsal seta (DS) located below SAT inner margin, partially obstructed by SAT (Figs. 19 g-h); 1 – 3 submarginal setae (B) located past SAT inner margin (Fig. 19 h); 15 – 20 marginal setae (C) initially long-stout and widely spaced, last few shorter and closer, blending into and difficult to differentiate from dorsal surface setae (Fig. 19 e); 36 – 62 ventral surface setae (D) scattered below submarginal and marginal setae, ending posteriorly at approximately ¾ the inner lacinia margin length (Fig. 19 f); dorsal surface setae (DSS) forming dense, laterally protruding, longitudinal band on and along inner-lateral margin, ending before posterior-most ventral surface setae (Fig. 19 f). Galea with 11 – 19 setae in sparse ventral row, apex with 2 – 3 setae. Maxillary Palp segments 2 – 3 with curved, apically rounded setae (Inset, Fig. 19 e). Pronotum with large median light area bordered by thick dark comma shaped bands typical of the I. sobria complex, a range of irregular shaped faded light brown areas usually present between the dark commas and fine dark clothing setae distributed evenly except on a few long light rugosites, lateral margins with broad light bands (Fig. 19 b). Meso and metanotum with contrasting pigment pattern and fine dark clothing setae (Fig. 19 c). Legs with numerous fine golden clothing setae and scattered erect spines on outer surface of femora, erect spines longest and concentrated along dorsal surfaces; fine silky setae sparse on dorsal surface of femora, numerous and continuous on tibia (Fig. 20 q); tibia with faint transverse band near proximal end. Abdominal terga usually with three longitudinal dark stripes; wide light median longitudinal band usually bisected with a median thin faded brown stripe; lateral pair of dark longitudinal stripes about twice as wide as median dark stripe, extending to lateral margins; numerous fine dark clothing setae and erect spines scattered dorsally; posterior margin with scattered long and numerous short spines in a concentrated row (Fig. 19 d).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA2F124FE83FF35906CFB0F.taxon	distribution	Distribution. Oregon, Washington. Occurrence in California not confirmed.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA2F124FE83FF35906CFB0F.taxon	diagnosis	Diagnosis. Isoperla tilasqua male larvae share the typical comma shaped dark pronotal bands common to the I. sobria complex (Fig. 19 b) and have similar numbers of submarginal (A) setae when compared to I. sobria (Table 2). The long, thin apically rounded setae on basal maxillary palpi segments 2 – 3 (Fig. 19 a Inset) are similar to I. baumanni (Fig. 5 e Inset). It is distinct from these species by having a partially light interocellar area connected to the posterior margin of head, a continuous light M shaped band above the anterior ocellus, and a relatively thin median longitudinal light band extending from the anterior ocellus to the light frontoclypeus area (Fig. 19 a).	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
D27B87A3FFA2F124FE83FF35906CFB0F.taxon	discussion	Remarks. The Mt. Shasta I. tilasqua female in the NMNH from California may be the first record for the state. The female western Isoperla taxonomy is known, but variations in the length and shape of the subgenital plate are possible. Isoperla sobria females from California and Oregon had elongate subgenital plates with basolateral margins nearly parallel and rounded apical margins. Eight I. tilasqua females reared from Meacham Creek, Umatilla County, Oregon, all had subgenital plates with median invaginations similar to I. gravitans (Fig. 111 in Szczytko & Stewart, 1979), but the lateral margins, similar to I. sobria, were nearly parallel. A reared or recently field collected male will be required to confirm this interesting and possible range extension.	en	Sandberg, John B. (2011): The Isoperla Of California (Plecoptera: Perlodidae); Larval Descriptions And A Key To 17 Western Nearctic Species. Illiesia 7 (22): 202-258, DOI: http://doi.org/10.5281/zenodo.4760320
