taxonID	type	description	language	source
1B32387A8314B27DF676A7E5FA3FA3DC.taxon	description	Males	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8314B27DF676A7E5FA3FA3DC.taxon	description	Females	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8310B27FF45AA7E4FEE8A2B1.taxon	description	(Figs. 1 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8310B27FF45AA7E4FEE8A2B1.taxon	materials_examined	Holotype ♂, California, Fresno County, Dry Creek, 7 mi NE Academy.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8310B27FF45AA7E4FEE8A2B1.taxon	description	Male. Aedeagus: sclerotized posterior process absent; body a long recurved tube without major lobes, tapering to a multi-lobed apex (Fig. 1 a); a pair of long, nearly parallel patches of fine spinulae along posteroapical margin (Figs. 1 a-b). Ninth tergum with mesoposterior bipartite to oval patches of stout dark spinulae and long fine scattered setae, tenth tergum with only a few small spinulae (Fig. 1 c). Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae (Fig. 1 d inset). Paraprocts: curved dorsally, length if straightened longer than combined first and second cercal segments, tapering gradually to long sharp apices (Fig. 1 c). Vesicle: rectangular, length half as long as wide (Fig. 1 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8310B27FF45AA7E4FEE8A2B1.taxon	discussion	The male of I. acula (I. quinquepunctata complex) is most similar to I. mormona and I. quinquepunctata, all lacking an aedeagal sclerotized process (Table 1). However, the similarity in other male taxonomic characters of the three species varies with I. acula and I. mormona possessing patches of fine spinulae near the apex of aedeagus; vesicle shape varies from lobelike (I. quinquepunctata) to rectangular (I. acula) and trapezoidal (I. mormona); abdominal terga 9 - 10 variable posteriorly with patches of stout setae (I. quinquepunctata) or patches of stout spinulae and scattered long setae (I. acula, I. mormona); paraproct length> than first and second cercal segments (I. acula) or subequal to first and second cercal segments (I. mormona, I. quinquepunctata); and paraproct shape variable, tapering gradually to sharp apices (I. acula), tapering abruptly to blunt apices (I. mormona) and in I. quinquepunctata, tapering gradually to blunt apices. The current study I. acula description agrees with those of Jewett (1962), Szczytko & Stewart (1979), and Bottorff et al. (1990).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8310B27FF45AA7E4FEE8A2B1.taxon	materials_examined	Additional Material Examined. CALIFORNIA, Shasta Co., Rock Creek, West Redding, 05 / VI / 2011, larvae, (ABLC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8310B271F450A01EFE59A0C8.taxon	description	(Figs. 2 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8310B271F450A01EFE59A0C8.taxon	description	Male. Aedeagus: sclerotized posterior process present; body with one posterobasal and one posteromedian lobe, dorsomedian apex with a pair of rounded lobes, and one anterior lobe (Fig. 2 a); sclerotized process length approximately 0.25 mm, recurved and rod-like, located below posterior lobes (Fig. 2 a), and apex clavate in posterior and lateral views (Figs. 2 a-b). Abdominal terga 8 - 9, 9, or 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to first and second cercal segments, tapering gradually to blunt apices (Fig. 2 c). Vesicle: pedunculate, length subequal to width, constricted near base with curved lateral margins, wider and rounded at apex (Fig. 2 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8310B271F450A01EFE59A0C8.taxon	discussion	Isoperla adunca (I. sordida complex) shares similar characters with I. umpqua (known only from Oregon, and a species that should also be included in the I. sordida complex). Both species have a clavate sclerotized process in lateral and posterior views, lack aedeagal spinule patches, possess pedunculate vesicles, and have similar paraproct lengths and shapes (Table 1). Primary differences involve tergal spinulae and two aedeagal characters: I. adunca has 4 lobes and I. umpqua has one; the sclerotized process length is approximately 0.25 mm for I. acula and approximately 0.5 mm for I. umpqua; and short stout spinulae present on terga 8 - 9 for I. umpqua only. Lastly, I. adunca wings are tinted and the wings of I. umpqua are hyaline. The I. adunca aedeagus and paraproct shapes differed from those described by Szczytko & Stewart (1979). In the current study, the aedeagus has four distinct lobes in lateral view (Fig. 2 a) and paraprocts curved dorsally (Fig. 2 c) vs. aedeagus with only one apical lobe and paraprocts deflected downward (Szczytko & Stewart 1979, figs. 159 - 160). Isoperla adunca, as with I. acula and I. miwok, is usually associated with small intermittent streams of the Sierra Nevada foothills from north to southcentral California (Bottorff et al. 1990, Sandberg 2011 b). The northern most distribution was recently found in Shasta County and the southwestern most distribution of I. adunca overlaps with I. denningi and I. mormona in Ventura and San Diego counties. Records for this species from Alameda and Santa Clara Counties are located in the Coastal Range.. California typically experiences high variation in precipitation (Haston & Michaelsen 1979) and 2013 is evidencing to be a drought year (http: // www. wrc. dri. edu /). Before completing its life cycle, especially in drought years, I. adunca must cope with drying conditions including rapidly warming water temperatures occurring in non-perennial streams. For example, mature larvae of I. adunca were collected on 24 April 2013 from Orestimba Creek (Stanislaus County, 119 m asl) when stream temperatures had already reached 26.94 ° C (L. E. Serpa, per. com.).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8310B271F450A01EFE59A0C8.taxon	materials_examined	Additional Material Examined. CALIFORNIA, Riverside Co., San Juan Creek, 0.4 mi (0.6 km) N Lion Canyon Creek, 19 / V / 2011, larvae, (ABLC); Santa Clara Co., Tributary to Arroyo Aguague, UCB Blue Oaks Ranch, N 37.37189, W 121.73289, 06 / V / 2012, larva (ABLC); Shasta Co., Rock Creek, West Redding, 05 / VI / 2011, larvae, (ABLC); Rock Creek, at Iron Mountain Rd., 04 / V / 2009, larvae (ABLC); Stanislaus Co., Orestimba Creek, 19.3 km E Newman, 37.289 ° N, 121.22008 ° W, 24 / IV / 2013, L. E. Serpa, Larvae, (JBSC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831EB271F436A3C3FBEEA323.taxon	description	(Figs. 3 a-d, 20 a)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831EB271F436A3C3FBEEA323.taxon	materials_examined	Holotype ♂, California, Plumas County, Domingo Spring, Domingo Spring Campground, 6 mi NW Chester.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831EB271F436A3C3FBEEA323.taxon	description	Male. Aedeagus: sclerotized posterior process absent; body with one posterobasal lobe, one posteromedian lobe and expanded apex, apex deeply inverted (Fig. 3 a); one large patch of spinulae concentrated below posteromedian lobe (Fig. 3 b), and a long thin patch along posteroapical margin (Fig. 3 c). Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to first cercal segment, tapering abruptly to blunt apices (Fig. 3 c). Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 3 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831EB271F436A3C3FBEEA323.taxon	discussion	The males of I. baumanni and I. tilasqua are very similar, with the exception of recently preserved specimens. Males of I. baumanni have yellow abdominal pigmentation which can be easily separated from the much darker I. tilasqua. The aedeagal spinulae and lobe characters are very similar; both species possess one large patch of spinulae concentrated below the posteromedian lobe, a long thin patch along posteroapical margin, and bulbous apex deeply inverted (Figs. 3 a-c, 17 a-c). Isoperla tilasqua differs slightly from I. baumanni (live everted) by usually possessing a pair of small apicolateral lobes (similar to I. sobria (Hagen 1874 )). Males of both species may be identified using the thin extended apical lobe characters illustrated in Szczytko & Stewart (1979, fig. 116; 1984, fig. 53); I. baumanni has only one extended tube-like lobe and I. tilasqua has two. Sandberg (2011 b) suggested that extended lobes are normally inverted internal structures, and evert only when using the KOH clearing-eversion method for preserved males (Szczytko & Stewart 1979). These lobes could not be everted using the live eversion, hot water fixing, and KOH clearing methods described in this study. The aedeagi of live everted I. baumanni and I. tilasqua were cleared in KOH to detect the inverted tube-like processes. The internal membrane of a single inverted apical process was visible inside the aedeagus of I. baumanni after clearing (Fig. 20 a). The apical inverted process could only be partially everted for I. baumanni, with the longitudinally striated apex remaining inverted. For I. tilasqua, a pair of inverted tube-like processes could be observed within the aedeagus, but could not be everted after clearing (Fig. 20 f). The I. baumanni aedeagal shape, stout spinule patches, paraproct and vesicle shape are also similar to I. gravitans (Needham & Claassen 1925) in Szczytko & Stewart (1979, figs. 106 - 110). Sandberg (2011 b) also had difficulty separating I. baumanni from I. tilasqua nymphs using lacinia characters and tentatively placed I. baumanni into the I. sobria species complex. The three species appear to have locally restricted distributions and further study will be necessary to understand species limits of I. baumanni, I. tilasqua, and I. gravitans.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831DB272F43DA7E4FBC8A3DD.taxon	description	(Figs. 4 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831DB272F43DA7E4FBC8A3DD.taxon	materials_examined	Holotype ♂, Oregon, Union County, Lick Creek, 6 mi E Medical Springs.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831DB272F43DA7E4FBC8A3DD.taxon	description	Male. Aedeagus: sclerotized posterior process present; body with one posterobasal lobe, one posteromedian lobe, one large dorsal lobe and one anterior lobe (Fig. 4 a); sclerotized process length> 0.5 mm, distal-projecting portion recurved and deeply bifurcate, apices of bifurcate arms with acute points and secondarily barbed (Figs. 4 a-c), and length of proximal-attached base (Fig. 4 a, 1) less than the total length of distal-projecting median arm (Fig. 4 a, 2), bifurcate arms (Fig. 4 a, 3), and apical tine (Fig. 4 a, 4). Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering abruptly to variable blunt to sharp apices (Fig. 4 c). Vesicle: pedunculate, length subequal to width, constricted near base with curved lateral margins, wider and rounded at apex (Fig. 4 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831DB272F43DA7E4FBC8A3DD.taxon	discussion	Isoperla bifurcata is most similar to I. fusca Needham & Claassen 1925, a species not known to occur in California and not included in this study. The vesicle shape for I. bifurcata differed from the previous description. In this study, the pedunculate vesicle length is subequal to width, and rounded at apex (Fig. 4 d). In Szczytko & Stewart (1979, fig. 164), the vesicle width appears greater than length and the apex is both described and illustrated as truncate. The I. bifurcata sclerotized process description and couplet 20 of the key to the males in Szczytko & Stewart (1979) are imprecise. The ambiguity is caused by not clearly defining the “ base ” character (there are two possible interpretations), and two different proximal-attached “ base ” lengths are illustrated in lateral view and upside down posterior view in Szczytko & Stewart (1979, figs. 165 C & 168, respectively). The written description provides one length character: “ arms of apical fork extending same length as base … (figs. 165 C & 168) ”. Figure 165 C (in Szczytko & Stewart 1979) is a lateral view of the process and does not provide a clear view of the apical fork length, but does indicate the entire distalprojecting portion of the sclerotized process is longer than the proximal-attached portion (agreeing with our observations). Only figure 168 in Szczytko & Stewart (1979) provides an accurate view of the “ arms of the apical fork ” length, illustrating both as half the length of the proximal-attached “ base ” portion (0.5 times shorter than our observations), and subequal to the “ base ” of the distal- projecting portion of the sclerotized process (agreeing with our observations). Couplet 20 provides another sclerotized process length character “ dorsal arms of sclerotized aedeagal process not extending beyond length of base … (figs. 165 C & 168) ”. Couplet 20 describes the lengths as they are illustrated in fig. 168 (inconsistent with our observations), but then conflicts with fig. 165 C because the dorsal arms (same as “ arms of apical fork ” above) extend beyond the length of the “ base ” or proximal- attached portion (agrees with our observations). The current study addresses this uncertainty by providing updated terminology for the four regions of the I. bifurcata sclerotized process: 1. base, proximal portion attached to aedeagal membrane, bifurcate posteriorly and apically recurved (Fig. 4 a, 1); 2. median arm, projecting ventrally from aedeagal membrane (Fig. 4 a, 2); 3. bifurcate arms, extending ventrally from median arm (Fig. 4 a, 3); and 4. short sharp subapical barb and slightly longer apical tine at apex of bifurcate arms (Fig. 4 a, 4). The total length of the I. bifurcata distal-projecting portion of the sclerotized process (median arm, bifurcate arms and apical tines) (Fig. 4 a, 2 + 3 + apical tine) is nearly 2 times the length of the proximalattached base (Fig. 4 a, 1); and the bifurcate arm + apical tine length (Fig. 4 a, 3 + apical tine) is subequal to median arm length (Fig. 4 a, 2). Additionally, the length from the ventral barb apex to the apical tine apex (Fig. 4 a, 4) ranged from subequal to less than the bifurcate arm length (Fig. 4 a, 3).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831DB272F43DA7E4FBC8A3DD.taxon	materials_examined	Additional Material Examined. CALIFORNIA, Shasta Co., Hat Creek, Hwy 44, 3 mi (4.8 km) SW Old Station, 16 / VII / 2011, D. R. Givens, ♂, ♀ (CSUC); Siskiyou Co., McCloud River, Hwy 89 Lower Falls Picnic Area 5.5 mi (8.8 km) E McCloud, 41.2402 ° N, 122.02441 ° W, 23 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 1 ♂ (JBSC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB274F469A7E4FC39A51D.taxon	description	(Figs. 5 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB274F469A7E4FC39A51D.taxon	materials_examined	Holotype ♂, California, Los Angeles County, 4 mi W Tanbark Flat.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB274F469A7E4FC39A51D.taxon	description	Male. Aedeagus: sclerotized posterior process present; body with two posterobasal lobes, one large posteroapical lobe, and one dorsolateral pair of rounded lobes (Fig. 5 a); sclerotized process length <0.5 mm, recurved and rod-like, apex clavate in lateral view (Fig. 5 a), bifurcate in posterior view, lateral apices short and rounded (Fig. 5 b), and width of expanded apicolateral lobes 0.09 - 0.10 mm. Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering gradually to blunt apices (Fig. 5 c). Vesicle: pedunculate, length subequal to width, constricted near base with curved lateral margins, wider and rounded at apex (Fig. 5 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB274F469A7E4FC39A51D.taxon	discussion	Isoperla denningi is common in southwestern California, from Santa Barbara County south to San Diego County and occasionally coexists with I. acula, I. adunca and I. mormona (Sandberg 2011 b). It is most similar to the species in the I. sordida complex, specifically I. sordida Banks 1906 (Table 1), with discernible differences in aedeagal characters. Both species have four aedeagal lobes in lateral view, however I. denningi has a pair of dorsal lobes and I. sordida has only one. The sclerotized processes are somewhat similar; both are slightly bifurcate with short rounded apices. The difference is the plane in which these apices lie: for I. sordida, the apical plane is perpendicular to the body of the process, and for I. denningi, the apical plane is parallel with the sclerotized process body. Additionally, the widths of the bifurcate apices differ: 0.09 - 1.0 mm for I. denningi and 0.18 - 0.20 mm for I. sordida.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB274F469A7E4FC39A51D.taxon	materials_examined	Additional Material Examined. CALIFORNIA, Riverside Co., San Juan Creek, 0.4 mi (0.6 km) N Lion Canyon Creek, 19 / V / 2011, larvae (ABLC); San Diego Co., Devils Canyon Creek, above San Mateo Canyon Creek, 16 / V / 2011, larvae (ABLC); King Creek, 1.1 mi (1.77 km) below Grove Drive, 30 / V / 2012, larvae (ABLC); Santa Ysebel Creek, 2 mi (3.2 km) S Dan Price Creek, 29 / V / 2011, larvae (ABLC); Juaquapin Creek, above Sweetwater River, 01 / VI / 2011, larvae (ABLC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB276F6D3A66AFE68A262.taxon	description	(Figs. 6 a-d, 20 b)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB276F6D3A66AFE68A262.taxon	materials_examined	Holotype ♂, Utah, Logan River.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB276F6D3A66AFE68A262.taxon	description	Male. Aedeagus: sclerotized posterior process present; body with one posterior lobe, one small dorsal lobe, and one large anterior lobe (Fig. 6 a); one small bulbous patch of spinulae above sclerotized process (Figs. 6 a-c); sclerotized process length approaching 0.5 mm when fully extended, blade-like in lateral view (Fig. 6 a), distal margin expanded and slightly membranous in posterior view (Fig. 6 b), and narrow proximal portion of sclerotized process sometimes extended past posterior aedeagal membrane (Fig. 6 a). Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering abruptly to blunt apices (Fig. 6 a). Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 6 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB276F6D3A66AFE68A262.taxon	discussion	Isoperla fulva is most similar to the two other I. marmorata complex species, I. marmorata and I. roguensis. These species differ in paraproct shape and aedeagal characters. The paraprocts taper abruptly to blunt apices in I. fulva, taper gradually to blunt apices in I. marmorata, and taper abruptly to tiny sharp apices in I. roguensis (Table 1). The distal margin of blade-like sclerotized processes is thin in I. marmorata, expanded in I. fulva and expanded and variably-shaped in I. roguensis. The aedeagus of this species was described with an additional pair of long narrow tubular lobes extending from the base of the anterodorsal lobe (Szczytko & Stewart 1979, fig. 138 C). When using the live eversion method, these processes remain inverted (Fig. 6 a); however two small areas in inverted membrane are present on anterior lobe C of this study (not discernible in Fig. 6 a). The live everted aedeagus was cleared in KOH, which allowed observation of an inverted pair of tube-like processes within the aedeagus, and openings along the anteroapical margin (Fig. 20 b). The small dorsal lobe B (Figs. 6 a & c) in the current study possesses a pair of minute, closely placed holes from which seminal fluid streamed after live eversion and fixing. These dorsal aedeagal openings require further study before their function can be determined.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB276F6D3A66AFE68A262.taxon	discussion	Isoperla fulva is putatively known from California based on three males and one female (El Dorado and Modoc counties - Jewett 1960) and Plumas County (Szczytko & Stewart 1979) collected in the 1940 ’ s and 1950 ’ s. No recent material (everted males) from California compares well with the Colorado and Utah specimens examined for this study, and the California I. fulva records were determined before the description of I. roguensis. The El Dorado County male was likely collected from Weber Creek, south of Camino, 10 miles (16 km) north of Placerville, where Sandberg (2011 b) collected I. marmorata and I. mormona.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A831BB276F6D3A66AFE68A262.taxon	materials_examined	Additional Material Examined. COLORADO, Larimer Co., Sand Creek, Ruby Wash, Red Mountain Open Space, 24 / V / 2012, B. C. Kondratieff & D. Givens, 5 ♂, 2 ♀ (CSUC); 17 / VI / 2012, B. C. Kondratieff & R. Stokes, 10 ♂, 3 ♀ (CSUC). OREGON, Harney Co., Trout Creek, Whitehorse Ranch Rd 18 mi (29 km) SE Fields, 42.17439 ° N, 118.43199 ° W, 20 - 21 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 2 ♂, 1 ♀ (JBSC); Union Co., Grande Ronde River, Hwy 244, Hilgard Junction State Park (Hwy 84), 45.34323 ° N, 118.24013 ° W, 22 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 2 ♂, 3 ♀ (JBSC). UTAH, Juab Co., Pole Creek, FR 016 below confluence Pole Canyon, 14 / VI / 2012, B. C. Kondratieff & R. W. Baumann, 10 ♂, 23 ♀ (CSUC); Salt Creek, Ponderosa Campground, 14 / VI / 2012, B. C. Kondratieff & R. W. Baumann, 2 ♂, 2 ♀ (CSUC); Utah Co., Nebo Creek, FR 405, 13 / VI / 2012, B. C. Kondratieff & R. W. Baumann, 1 ♂, 8 ♀ (CSUC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8319B276F41AA175FC22A322.taxon	description	(Figs. 7 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8319B276F41AA175FC22A322.taxon	materials_examined	Holotype ♂, California, Humboldt County, Dragsaw Spring @ Rd 13 N 01.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8319B276F41AA175FC22A322.taxon	description	Male. Aedeagus: sclerotized posterior process present; body with one posterior lobe, one large dorsal lobe, and a pair of small anterolateral lobes (Fig. 7 a); one posterobasal patch of spinulae scattered below the sclerotized process and a long narrow posteroapical spinule patch concentrated above the sclerotized process (Figs. 7 a-b); sclerotized process length <0.5 mm, digitate, apex a blunt point, and capable of complete (Fig. 7 a) to partial eversion (Fig. 7 c). Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering gradually to blunt apices (Fig. 7 c). Vesicle: pedunculate, length subequal to width, constricted near base with curved lateral margins, wider and rounded at apex (Fig. 7 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8319B276F41AA175FC22A322.taxon	discussion	Isoperla laucki is most similar to I. marmorata (Table 1), with diagnostic differences in aedeagal spinule patch shape, location of sclerotized process, and sclerotized process shape. The spinules form an elliptical shaped patch distinctly separated from and placed above the insertion of the sclerotized process. The more rounded and in one case, bi-hemispherical shaped spinule patches of the I. marmorata complex are all placed above and adjacent to the insertion of the posterior sclerotized process. The I. laucki sclerotized process length is <0.5 mm, has parallel lateral margins, and a bluntly rounded apex. The sclerotized processes of the I. marmorata complex are longer (approaching 0.5 mm), and have expanded dorsal and ventral margins forming a blade-like apex with variable distal margins. The above male description, including live everted aedeagal characters, agrees with the previous description of the aedeagus based upon scanning electron microscope preparation (Baumann & Lee 2009, figs. 1 - 8). It was not noted in their methods if the live everted aedeagus was fixed in hot water. An unfixed aedeagus, after live eversion, will usually invert or deflate slightly, and might explain the slightly larger and expanded dorsal lobe in our study (Fig. 7 a).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8319B276F41AA175FC22A322.taxon	materials_examined	Additional Material Examined. CALIFORNIA, Humboldt Co., Unnamed tributary of Boise Creek, Hwy 299, 01 / V / 2011, J. B. Sandberg, B. C. Kondratieff, 1 ♀ (JBSC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8318B277F5D3A600FB27A79D.taxon	description	(Figs. 8 a-d, 20 c)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8318B277F5D3A600FB27A79D.taxon	materials_examined	Holotype ♀, Nevada.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8318B277F5D3A600FB27A79D.taxon	description	Male. Aedeagus: sclerotized posterior process present; body with one small posterior lobe, one dorsal lobe and an anterior lobe (Fig. 8 a); one small patch of spinulae concentrated on the inverted membrane above sclerotized process (Figs. 8 a-b); sclerotized process approaching 0.5 mm when fully extended, blade-like in lateral view (Fig. 8 a), distal margin thin in posterior view (Fig. 8 b), and narrow proximal portion of sclerotized process usually inverted inside posterior aedeagal membrane. Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering gradually to long blunt apices (Fig. 8 c). Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 8 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8318B277F5D3A600FB27A79D.taxon	discussion	The aedeagus of I. marmorata is more similar to I. fulva than to I. roguensis with similar numbers of spinule patches, patch shapes and positions. The I. marmorata aedeagus possesses two anteroapical small areas of inverted membrane which form the bases of the internal tube-like structures. Additionally, a pair of very small holes is present on the dorsal surface, usually on a minute lobe (not visible in Figs. 8 a & 8 c). The pairs of inverted membrane areas and minute holes occasionally have fixed streaming seminal fluid still attached. The previous I. marmorata aedeagal description did not include extended apical tube-like lobes (Szczytko and Stewart 1979, fig. 123). After clearing the everted aedeagus in KOH, a pair of inverted tube-like processes were observed within the aedeagus and attached to the small inverted areas (openings) upon the anteroapical margin (Fig. 20 c). It is possible that the previous description was based upon a live everted male that was not cleared. Isoperla marmorata wing and body color varies significantly in California. Typically at lower elevations and into the foothills, abdominal coloration is mostly yellow (reddish-yellow in life) and hindwing anal areas are lightly tinted. An exception occurs at Butte Creek (near Chico) where both wings are completely tinted and males have a dark wide ventral band on the ninth sternum. At a higher elevation Big Chico Creek location (Tehama Co.), the abdomen is yellow with multiple brown markings and dark wings. An extreme adult phenotype of this species is found at Prairie Creek (Humboldt Co.) where the abdomen is almost completely brown and the wings nearly black (J. J. Lee, pers. com.).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8318B277F5D3A600FB27A79D.taxon	materials_examined	Additional Material Examined. CALIFORNIA, Siskiyou Co., McCloud River, Hwy 89 Lower Falls Picnic Area 5.5 (8.8 km) mi E McCloud, 41.2402 ° N, 122.02441 ° W, 23 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 3 ♂, 1 ♀ (JBSC). OREGON, Lake Co., Deep Creek, Hwy 140, 5.5 mi (8.8 km) E Adel, 42.18564 ° N, 119.99512 ° W, 20 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 4 ♂, 2 ♀ (JBSC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8318B269F6AFA4F6FE79A76C.taxon	description	(Figs. 9 a-d, 20 d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8318B269F6AFA4F6FE79A76C.taxon	materials_examined	Holotype ♂, California, El Dorado County, Indian Creek, 3.3 km NE Michigan Bar Bridge.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8318B269F6AFA4F6FE79A76C.taxon	description	Male. Aedeagus: sclerotized posterior process absent; body with one small posterior lobe, one large dorsal lobe and a pair of small pointed lobes on apicolateral margins (Fig. 9 a-b); a pair of long curved patches of spinulae on posteroventral surface (Fig. 9 b), and a broad patch of spinules on the posteroapical surface (Figs. 9 a-c). Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering abruptly to blunt apices (Fig. 9 c). Vesicle: lobe barely perceptible, vestigial when present, widest at base with broadly rounded apex (Fig. 9 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8318B269F6AFA4F6FE79A76C.taxon	discussion	Isoperla miwok is most similar to the other species included in the I. sobria complex based on the absence of an aedeagal posterior sclerotized process, and presence of stout spinules arranged in variable patches (Table 1). It is distinctive among the western Nearctic species in possessing a double band of stout spinulae on the aedeagal posterobasal margin. The current study aedeagal description conforms to the previous description. However, the live everted and fixed aedeagus lacks the single extended tube-like lobe on the anteroapical margin (Bottorff et al. 1990, fig. 4). The anterior margin in this study possesses at least one anteromedian pair of inverted membrane areas (openings) which differs from the original description. A second smaller and more apical pair is also present. Clearing the everted and fixed aedeagus in KOH allowed observation of the anteroapical and anteromedian inverted processes inside the aedeagal body (Fig. 20 d, dorsal aspect providing the best view).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8306B269F462A464FBC8A648.taxon	description	(Figs. 10 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8306B269F462A464FBC8A648.taxon	materials_examined	Holotype ♀, Utah, Utah County, Vinyard.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8306B269F462A464FBC8A648.taxon	description	Male. Aedeagus: sclerotized posterior process absent; body a long recurved tube with one small dorsoanterior lobe, tapering to a multi-lobed apex (Figs. 10 a-b); a thin light dorsoapical band of fine spinulae concentrated somewhat above bi-lobed tip (Figs. 10 a-b). Mesoposterior area of ninth tergum with bipartite patches of stout dark spinulae and long fine scattered setae, tenth tergum without spinulae (Fig. 10 c). Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering abruptly to blunt apices (Fig. 10 c). Vesicle: trapezoid shaped, length subequal to width, constricted near base with tapered and straight lateral margins (base wider than apex), apex truncate (Fig. 10 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8306B269F462A464FBC8A648.taxon	discussion	Isoperla mormona is most similar to I. acula and I. quinquepunctata (Table 1). See comments under I. acula.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8306B269F462A464FBC8A648.taxon	materials_examined	Additional Material Examined. CALIFORNIA, Inyo Co., Rawson Creek, 1.1 mi (1.8 km) above Gerkin Rd, ~ 7.5 mi (12.1 km) S Bishop (Hwy 395), 37.28640 ° N, 118.40420 ° W, 25 / VII / 2012, larvae (ABLC). San Diego Co., Santa Ysebel Creek, 2 mi (3.2 km) S Dan Price Creek, 29 / V / 2011, larvae (ABLC). OREGON, Harney Co., Trout Creek, NFD 395 Rd 4.25 mi (6.8 km) E Idlewild CG (Hwy 395), 43.80484 ° N, 118.91082 ° W, 21 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 4 larva; Klamath Co., Sprague River, Hwy 140 unnamed access 4.74 mi (7.6 km) E Beatty, 42.44096 ° N, 121.18719 ° W, 19 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 1 ♂ (JBSC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8306B26BF6C3A540FDCCA013.taxon	description	(Figs. 11 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8306B26BF6C3A540FDCCA013.taxon	materials_examined	Holotype ♂, Oregon, Curry County, Floras Creek.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8306B26BF6C3A540FDCCA013.taxon	description	Male. Aedeagus: sclerotized posterior process absent; body with one posterobasal lobe, one small posteroapical lobe, and a pair of anterolateral lobes (Fig. 11 a); Mesoposterior area of ninth tergum with bipartite patches of long fine light spinulae mixed with patches of long clear setae (best viewed from lateral angle). Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering abruptly to blunt apices (Fig. 11 c) apices usually secondarily barbed along ventral margin. Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 11 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8306B26BF6C3A540FDCCA013.taxon	discussion	Isoperla pinta is very similar to I. phalerata Needham 1917, a species not known to occur in California. However, interestingly, Jewett (1954) designated the male allotype of I. phalerata from Union County, in northeastern Oregon, whereas the holotype locality of I. pinta is Curry County, in southwestern Oregon, bordering northern California (Frison 1937). Isoperla phalerata is presumably rarely collected and adults and larvae may be readily confused with I. pinta. At present, the most useful characters for separating adults of the two species include the pigment pattern of the head and pronotum (lighter I. phalerata vs. darker I. pinta) described in Szczytko & Stewart (1979, figs. 56 & 75); and variable cross veins between radial sector and M vein of forewings (one for I. pinta vs. more than one for I. phalerata) described in Smith (1917, fig. 65), Szczytko & Stewart (1979, fig. 60), and Béthoux (2005, fig. 12). Both species lack a sclerotized aedeagal process, distinct aedeagal spinule patches, and possess wide and short lobe-like vesicles. Dissimilar to the I. pinta continuous tergal spinule band pattern described previously (Szczytko & Stewart 1979, fig. 78); males observed in this study possess bipartite patches of fine light spinulae mixed with long clear setae. This generally matches the patch shape previously described for I. phalerata (Szczytko & Stewart 1979, fig. 59). Additionally, the ventral barb of the paraproct was vestigial in many specimens. When vestigial, its ventral margin curved interiorly, was in line with adjacent connective membrane instead of protruding ventrally, and was discernible only by darker pigment than the surrounding ventral paraproct.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8306B26BF6C3A540FDCCA013.taxon	materials_examined	Additional Material Examined. CALIFORNIA, Marin Co., Lagunitas Creek, 0.17 mi (0.3 km) N Jewell on Sir Francis Drake Blvd, N 38.03917 °, W 122.74611 °, 04 / II / 2013, L. Serpa, 1 Larva, (JBSC). OREGON, Klamath Co., Sprague River, Hwy 140 unnamed access 4.74 mi (7.6 km) E Beatty, 42.44096 ° N, 121.18719 ° W, 19 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 10 ♂, 10 ♀ (JBSC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26BF416A384FB1FA0E5.taxon	description	(Figs. 12 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26BF416A384FB1FA0E5.taxon	materials_examined	Holotype ♀, New Mexico, Las Vegas, Gallinas River.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26BF416A384FB1FA0E5.taxon	materials_examined	Holotype ♂, South Dakota, Lawrence County, Spearfish River, Spearfish.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26BF416A384FB1FA0E5.taxon	description	Male. Aedeagus: sclerotized posterior process absent; body of aedeagus with a small posteromedian lobe covered with minute spinulae, one posteroapical lobe, one dorsal lobe, and an anterior lobe (Fig. 12 a). Posterolateral margin of ninth and tenth terga with patches of long stout setae, fewer and smaller on tergum ten (Fig. 12 c). Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering gradually to blunt apices (Fig. 12 c). Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 12 d), sometimes appears constricted along inner sclerotized lateral margins with wider and broadly rounded membranous outer lateral margins.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26BF416A384FB1FA0E5.taxon	discussion	The live everted aedeagus agrees generally with the previous description (Szczytko & Stewart 1979, fig. 36). In this study, the small lobe A is covered with minute spinulae (Fig. 12 a) vs. devoid of spinulae (Szczytko & Stewart 1979, fig. 36 D), and a truncated dorsal lobe C is present (Fig. 12 a) vs. absent in Szczytko & Stewart (1979, fig. 36). Isoperla quinquepunctata, a geographically widespread western Nearctic species (Szczytko & Stewart 1979) is most similar to I. acula and I. mormona (Table 1). See comments under I. acula.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26BF416A384FB1FA0E5.taxon	materials_examined	Additional Material Examined. OREGON, Grant Co., Silvies River, Hwy 395, 0.6 mi (0.9 km) S Seneca, 44.12529 ° N, 118.97443 ° W, 21 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 6 ♂, 3 ♀ (JBSC); Harney Co., Trout Creek, Whitehorse Ranch Rd 18 mi (28.9 km) SE Fields, 42.17439 ° N, 118.43199 ° W, 21 / V / 2013, J. B. Sandberg, B. C. Kondratieff, larvae (JBSC); Klamath Co., Sprague River, Hwy 140 unnamed access 4.74 mi (7.6 km) E Beatty, 42.44096 ° N, 121.18719 ° W, 19 - 20 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 2 ♀ (JBSC); Lake Co., Crooked Creek, Hwy 395 at Chandler State Park 17 mi (27.3 km) N Lakeview, 42.41125 ° N, 120.29129 ° W, 20 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 4 ♂, 3 ♀ (JBSC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26DF6D3A3E3FD9CA6B6.taxon	description	(Figs. 13 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26DF6D3A3E3FD9CA6B6.taxon	materials_examined	Isoperla rainiera Jewett 1954. Holotype ♂, Washington, Pierce County, Mount Rainier National Park.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26DF6D3A3E3FD9CA6B6.taxon	description	Male. Aedeagus: sclerotized posterior process present; body of aedeagus with one small posterior lobe, one dorsal lobe, and one anterior lobe (Fig. 13 a); sclerotized process length <0.5 mm, recurved, crescent shaped, apex broadly rounded with two lateral sharp hook-like projections directed anteriorly (Figs. 13 a-c). Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scalelike setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering gradually to long sharp apices (Fig. 13 c). Vesicle: pedunculate, length subequal to width, constricted near base with curved lateral margins, wider and rounded at apex (Fig. 13 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26DF6D3A3E3FD9CA6B6.taxon	discussion	Isoperla rainiera shares several characters with species of the I. sordida complex (Table 1). It differs from these species in paraproct shape and aedeagal characters. The paraprocts taper gradually to sharp apices and the apex of the sclerotized process is crescent shaped. This species is not known from California, recorded from Oregon and Washington (Szczytko & Stewart 1979).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8304B26DF6D3A3E3FD9CA6B6.taxon	materials_examined	Material Examined. WASHINGTON, Skamania Co., Tyee Spring, Meadow Creek Rd, 0.44 mi (0.7 km) N of NFD 3065 & NFD 30, 45.87568 ° N, 121.97095 ° W, 16 / VI / 2011, 2 ♂, 10 ♀ (JBSC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26DF433A41FFC22A725.taxon	description	(Figs. 14 a-d, 20 e)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26DF433A41FFC22A725.taxon	materials_examined	Holotype ♂, Oregon, Curry County, mouth of Rogue River.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26DF433A41FFC22A725.taxon	materials_examined	Holotype ♂, California, Humboldt County, Klamath River @ junction of Aikens Creek. Syn. Sandberg, 2011 b.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26DF433A41FFC22A725.taxon	description	Male. Aedeagus: sclerotized posterior process present; body of aedeagus with one posterior lobe, one large dorsal lobe, and one anterior lobe (Fig. 14 a); one bulbous and usually bi-hemispherical shaped patch of spinulae above sclerotized process and a small pair of spinule patches placed laterally (Figs. 14 a-c); sclerotized process length approaching 0.5 mm, blade-like in lateral view (Fig. 14 a), distal margin expanded and slightly membranous in posterior view (Fig. 14 b), shape of distal expanded margin variable, and narrow proximal portion of sclerotized process usually inverted inside posterior aedeagal membrane. Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering abruptly to tiny sharp apices (Fig. 14 c). Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 14 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26DF433A41FFC22A725.taxon	discussion	Isoperla roguensis shares similar characters with the species of the I. marmorata complex (Table 1). See comments under I. fulva. Three distinct spinule patches distinguishes this species. Recently, Sandberg (2011 b) placed I. karuk Baumann & Lee 2009 as a junior subjective synonym. The previously described everted anterior tubelike lobes (Szczytko & Stewart 1984, fig. 55) remained inverted after live eversion, their positions indicated by a pair of small inverted areas of membrane (openings). After clearing in KOH, the internal tubelike processes were visible with openings along anteroapical margin (Fig. 20 e, ventral aspect provided clearest view).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26DF433A41FFC22A725.taxon	materials_examined	Additional Material Examined. CALIFORNIA, Plumas Co., MF Feather River, FR 12 N 61 X access off Hwy 70, 10.5 mi (16.9 km) SE Quincy, 39.86453 ° N, 120.76138 ° W, 18 / VI / 2013, J. L. York, 1 ♂, 1 ♀ (JBSC); Jamison Creek, 1.6 mi (2.6 km) E Two Rivers exit off Hwy 70, 39.813 ° N, 120.6821 ° W, 19 / VI / 2013, J. L. York, 1 ♀ (JBSC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26FF6D0A4A3FE8FA601.taxon	description	(Figs. 15 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26FF6D0A4A3FE8FA601.taxon	materials_examined	Holotype ♀, “ Colorado mountains. ”	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26FF6D0A4A3FE8FA601.taxon	materials_examined	Holotype ♀, “ Colorado mountains. ”	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26FF6D0A4A3FE8FA601.taxon	description	Male. Aedeagus: sclerotized posterior process absent; body of aedeagus typically with one anterior lobe and a pair of conical dorsal lobes (Figs. 15 a-c); in one male collected in copula, a small posteroapical lobe was present (Figs. 15 a-b); one long median patch of spinulae along posterior margin (Figs. 15 a-c). Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering abruptly to blunt points (Fig. 15 c). Vesicle: lobe barely perceptible, at best represented by an area of lighter pigment (Fig. 15 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8302B26FF6D0A4A3FE8FA601.taxon	discussion	Isoperla sobria is most similar to I. miwok (Table 1), with both included in the I. sobria complex (Bottorff et al. 1990). They differ most in the shape of the aedeagal spinule patch. In I. sobria, there is only one median patch on the posterobasal margin; in I. miwok, there is a posteroapical and a posterobasal patch, and the latter is concentrated into two nearly parallel bands. Isoperla sobria is distributed in higher elevation permanent streams in central to northcentral California. Isoperla miwok, as with I. acula and I. adunca, is usually associated with small intermittent streams of the Sierra Nevada foothills in north-central California, with one unconfirmed Lake County, Coastal Range location (Sandberg 2011 b).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B26FF456A58FFD94A2F9.taxon	description	(Figs. 16 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B26FF456A58FFD94A2F9.taxon	materials_examined	Holotype ♂, California, Los Angeles.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B26FF456A58FFD94A2F9.taxon	description	Male. Aedeagus: sclerotized posterior process present; body of aedeagus with two posterior lobes, one dorsal lobe, and one anterior lobe (Fig. 16 a); sclerotized process length approaching 0.5 mm, partially recurved and rod-like, apex expanded, flattened and projecting dorsally in lateral view (Figs. 16 a), bifurcate subapically with two ventrally directed rounded lobes in posterior view (Fig. 16 b inset), width of lobes 0.18 - 0.20 mm. Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering gradually to long blunt apices (Fig. 16 c). Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 16 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B26FF456A58FFD94A2F9.taxon	discussion	Isoperla sordida has been recently collected in two high elevation (above 1524 m), spring fed or snow melt eastern Sierra Nevada streams (Sandberg 2011 b); and shares similar characters with other species from the I. sordida complex and I. umpqua (Table 1). It is most similar to I. denningi. See comments under I. denningi.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B26FF438A1D7FC0AA188.taxon	description	(Figs. 17 a-d, 20 f)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B26FF438A1D7FC0AA188.taxon	materials_examined	Holotype ♂, Oregon, Benton County, Oak Creek.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B26FF438A1D7FC0AA188.taxon	description	Male. Aedeagus: sclerotized posterior process absent; body with two large posterior lobes and expanded apex, apex deeply inverted, with a pair of small conical lobes at apicolateral margins (Fig. 17 a); one large patch of spinulae concentrated below posteromedian lobe (Fig. 17 b), and a long thin patch along posteroapical margin (Fig. 17 c). Abdominal terga 8 - 9, 9, 9 - 10: without stout spinulae or long stout setae. Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to first cercal segment, tapering abruptly to blunt apices (Fig. 17 c). Vesicle: rounded lobe, widest at base with broadly rounded apical margin (Fig. 17 d).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B26FF438A1D7FC0AA188.taxon	discussion	Isoperla tilasqua is not known from California, recorded from Oregon and Washington (Szczytko & Stewart 1979, Sandberg 2011 b) and is most similar to I. baumanni. See comments under I. baumanni. After live eversion, the extended tube-like lobes described in Szczytko & Stewart (1979, fig. 116) remained inverted, their locations could be identified by small inverted membrane areas (openings). After clearing in KOH, a pair of tube-like internal processes was discernible within the body of the aedeagus, with openings along the anteroapical margin (Fig. 20 f).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B26FF438A1D7FC0AA188.taxon	materials_examined	Additional Material Examined. OREGON, Harney Co., Trout Creek, NFD 395 Rd 4.25 mi (6.8 km) E Idlewild CG (Hwy 395), 43.80484 ° N, 118.91082 ° W, 21 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 4 Larvae, 2 ♂, 3 ♀ (reared) (JBSC); Umatilla Co., Camas Creek, Hwy 395 Ukiah-Dale Forest State Park 1.1 mi (1.8 km) S Hwy 244 intersec, 45.1241 ° N, 118.97251 ° W, 22 / V / 2013, J. B. Sandberg, B. C. Kondratieff, 2 ♂, 1 ♀ (JBSC).	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B261F6A0A107FEBFA02C.taxon	description	(Figs. 18 a-d)	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B261F6A0A107FEBFA02C.taxon	materials_examined	Holotype ♂, Oregon, Douglas County, Muir Creek, Hwy 230, downstream from bridge.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
1B32387A8300B261F6A0A107FEBFA02C.taxon	description	Male. Aedeagus: sclerotized posterior process present; body with one large dorsoanterior lobe (Fig. 18 a); sclerotized process length approximately 0.5 mm, recurved and rod-like, with parallel lateral margins, apex clavate, and distal margin rounded in lateral and posterior views (Figs. 18 a-c). Mesoposterior area of eighth and ninth terga with bipartite patches of short stout spinulae and long fine scattered setae (Fig. 18 c). Posterolateral margins of at least abdominal segment 8 with scale-like setae clustered in brushes of several setae. Paraprocts: curved dorsally, length if straightened subequal to combined first and second cercal segments, tapering gradually to long blunt apices (Fig. 18 c). Vesicle: pedunculate, length subequal to width, constricted near base with curved lateral margins, wider and rounded at apex (Fig. 18 d). Based upon the presence of a sclerotized posterior process, absence of distinct aedeagal spinule patches, and pedunculate vesicle shape, I. umpqua is placed within the I. sordida complex (Table 1). It differs from all other I. sordida complex species by possessing short stout spinulae arranged in bipartite patches along mesoposterior margins of terga 8 - 9. The clavate sclerotized posterior process is most similar to I. adunca; however its length is approximately twice as long as I. umpqua. Isoperla umpqua is known only from Oregon, and similar to I. baumanni, is from a single location.	en	Sandberg, John B., Kondratieff, Boris C. (2013): The Isoperla Of California (Plecoptera: Perlodidae); Updated Male Descriptions And Adult Keys For 18 Western Nearctic Species. Illiesia 9 (5): 34-64, DOI: 10.5281/zenodo.4760870
