taxonID	type	description	language	source
5C6687DE5F1CB75B0A8DFC806408FA32.taxon	description	= group atrebatinus: Müller-Liebenau 1969: 150; = group propinquus: Morihara & McCafferty 1979 a: 130; 1979 b: 146; = group molawinensis: Müller-Liebenau 1984: 274; = molawinensis-atrebatinus-propinquus complex: Müller-Liebenau & Hubbard 1985: 556.	en	Kluge, Nikita, Sivaruban, T., Srinivasan, Pandiarajan, Barathy, S., Isack, Rajasekaran (2023): Diagnosis, variability, distribution and systematic position of Labiobaetis pulchellus (Müller-Liebenau & Hubbard 1985) (Ephemeroptera, Baetidae, Baetis s. l.). Zootaxa 5264 (1): 94-108, DOI: 10.11646/zootaxa.5264.1.6, URL: http://dx.doi.org/10.11646/zootaxa.5264.1.6
5C6687DE5F1CB75B0A8DFC806408FA32.taxon	materials_examined	Type species: Baetis atrebatinus Eaton, 1870.	en	Kluge, Nikita, Sivaruban, T., Srinivasan, Pandiarajan, Barathy, S., Isack, Rajasekaran (2023): Diagnosis, variability, distribution and systematic position of Labiobaetis pulchellus (Müller-Liebenau & Hubbard 1985) (Ephemeroptera, Baetidae, Baetis s. l.). Zootaxa 5264 (1): 94-108, DOI: 10.11646/zootaxa.5264.1.6, URL: http://dx.doi.org/10.11646/zootaxa.5264.1.6
5C6687DE5F1CB75B0A8DFC806408FA32.taxon	discussion	Comments. The groups atrebatinus, propinquus, molawinensis in the genus Baetis Leach, 1815 were proposed by different authors in application to local faunas: the group atrebatinus for the European fauna (Müller-Liebenau 1969), the group propinquus for the North American fauna (Morihara & McCafferty 1979 a; 1979 b) and the group molawinensis for the Oriental fauna (Müller-Liebenau 1984). In other respects these three groups represented one and the same taxon, which was outlined and characterized by Novikova & Kluge (1987) as the taxon Labiobaetis (initially with a rank of subgenus, later the rank was raised to a genus). Recently Labiobaetis contains 170 formally described species (including invalid synonyms) and many undescribed species from Holarctic, Afrotropical, Oriental and Australian Regions. The genus Labiobaetis has very diverse structure of larvae, imagines and eggs, and attempts to divide it into species-groups were suggested. Particularly, Kaltenbach & Gattolliat (2018; 2019; 2021) established several species groups for Oriental (including New Guinean) species based on larval characters. However, total classification of Labiobaetis is still absent. A species group tricolor can be outlined based on imaginal and larval characters.	en	Kluge, Nikita, Sivaruban, T., Srinivasan, Pandiarajan, Barathy, S., Isack, Rajasekaran (2023): Diagnosis, variability, distribution and systematic position of Labiobaetis pulchellus (Müller-Liebenau & Hubbard 1985) (Ephemeroptera, Baetidae, Baetis s. l.). Zootaxa 5264 (1): 94-108, DOI: 10.11646/zootaxa.5264.1.6, URL: http://dx.doi.org/10.11646/zootaxa.5264.1.6
5C6687DE5F1CB7580A8DF9C46380FAB5.taxon	description	(Figs 1 – 60)	en	Kluge, Nikita, Sivaruban, T., Srinivasan, Pandiarajan, Barathy, S., Isack, Rajasekaran (2023): Diagnosis, variability, distribution and systematic position of Labiobaetis pulchellus (Müller-Liebenau & Hubbard 1985) (Ephemeroptera, Baetidae, Baetis s. l.). Zootaxa 5264 (1): 94-108, DOI: 10.11646/zootaxa.5264.1.6, URL: http://dx.doi.org/10.11646/zootaxa.5264.1.6
5C6687DE5F1CB7580A8DF9C46380FAB5.taxon	description	Larval characters Antenna: scape with distolateral process. The same in some other Labiobaetis, including the type species, L. atrebatinus. For the species lacking this process, a separate genus Cymulabaetis McCafferty & Waltz, 1995 was established, but at present it is not accepted (Lugo-Ortiz & McCafferty 1997). Labrum: setae forming submarginal arc are simple and sparse; the first two setae after the central seta are closely together (Fig. 13). This character is known for L. tricolor (illustrated in Ikonomov 1962: fig. 13: 1), L. propinquus (illustrated in Morihara & McCafferty 1979 a: fig. 11; 1979 b: fig. 30 b), L. calcaratus (Keffermüller, 1972) (personal observation by Kluge) and L. pulchellus (illustrated in Müller-Liebenau & Hubbard 1985: fig. 6 a). The same in some other species groups, but in contrast to some other Labiobaetis (including the type species, L. atrebatinus), which have the submarginal setal arc consisted of other kinds of setae (e. g. feathered, lanceolate, or spatulate), or consisted of simple setae, but without two setae brought together. Hypopharynx: medial tuft of stout setae well developed and short (Fig. 17). Maxillary palp: distal excavation of inner margin present (Fig. 18). Labium: Paraglossae wide; labial palp with broad distomedial protuberance of 2 nd segment and conical 3 rd segment (Fig. 16). The same in many other Labiobaetis. Abdominal cuticular coloration: Varies individually from uniform color pattern on all abdominal terga I – IX (Figs 10, 12) to differentiated, with tergum V having largest unpaired median blank (Figs 4, 7, 11). This individual variation is known for L. pulchellus (see below) and for L. tricolor: uniform coloration of L. tricolor is illustrated by Ikonomov (1962: fig. 12), contrasting coloration with largest median blank on the 5 th tergum is illustrated by Müller-Liebenau (1969: Abb. 113). Imaginal characters Gonostyli: 1 st segment parallel-sided, with prominent rectangular apical-inner angle; 2 nd segment narrow in proximal part and wider in distal part; 3 rd segment short and roundish, sharply separated (Figs 56 – 60). Probably, such shape of gonostyli occurs in this group only. Penial bridge: Projected caudally forming a pair of rounded lobes with deep concavity between them, with sharply pointed, sclerotized denticle arising from middle of this concavity (Figs 56, 57, 60). The same structure of the penial bridge occurs in L. atrebatinus and L. frondalis (McDunnough, 1925) (both these species differ from the tricolor group by non-angulate 1 st gonostylus segment and by widened setae of the submarginal arc on the larval labrum). Hind wing: The described species of the tricolor group have narrow hind wings with two longitudinal veins, either lacking costal projection (in L. tricolor, L. propinquus and L. pulchellus – Figs 20, 22, 24, 26), or with a small costal projection (in L. calcaratus). One of us (Kluge) has reared material of an un-described species from Sulawesi, which belongs to the tricolor group and completely lacks hind wings.	en	Kluge, Nikita, Sivaruban, T., Srinivasan, Pandiarajan, Barathy, S., Isack, Rajasekaran (2023): Diagnosis, variability, distribution and systematic position of Labiobaetis pulchellus (Müller-Liebenau & Hubbard 1985) (Ephemeroptera, Baetidae, Baetis s. l.). Zootaxa 5264 (1): 94-108, DOI: 10.11646/zootaxa.5264.1.6, URL: http://dx.doi.org/10.11646/zootaxa.5264.1.6
5C6687DE5F1CB7580A8DF9C46380FAB5.taxon	distribution	Distribution. Holarctic and Oriental Region. Species composition. Following species are known as larvae and imagines reliably associated by rearing: Palaearctic Labiobaetis tricolor, Nearctic L. propinquus, Palaearctic L. calcaratus and Oriental L. pulchellus. Some other Oriental species belonging to this group are described either only as imagines, or only as larvae. Particularly, Labiobaetis ulmeri (Müller-Liebenau, 1981) known as male imago from Sumatra has the structure of gonostyli and penial bridge characteristic for the tricolor group.	en	Kluge, Nikita, Sivaruban, T., Srinivasan, Pandiarajan, Barathy, S., Isack, Rajasekaran (2023): Diagnosis, variability, distribution and systematic position of Labiobaetis pulchellus (Müller-Liebenau & Hubbard 1985) (Ephemeroptera, Baetidae, Baetis s. l.). Zootaxa 5264 (1): 94-108, DOI: 10.11646/zootaxa.5264.1.6, URL: http://dx.doi.org/10.11646/zootaxa.5264.1.6
5C6687DE5F1FB7560A8DFA2B6374F9C5.taxon	description	(Figs 1 – 64)	en	Kluge, Nikita, Sivaruban, T., Srinivasan, Pandiarajan, Barathy, S., Isack, Rajasekaran (2023): Diagnosis, variability, distribution and systematic position of Labiobaetis pulchellus (Müller-Liebenau & Hubbard 1985) (Ephemeroptera, Baetidae, Baetis s. l.). Zootaxa 5264 (1): 94-108, DOI: 10.11646/zootaxa.5264.1.6, URL: http://dx.doi.org/10.11646/zootaxa.5264.1.6
5C6687DE5F1FB7560A8DFA2B6374F9C5.taxon	materials_examined	Material examined. SRI LANKA: boundary between Uva province and Central province, tributary of river Uma near Randenigala dam, 14 – 15. I. 2011, coll. N. Kluge & L. Sheyko: 1 L-S-IJ, 1 L-SJ, 2 L-S-I ♀ (ZIN); Central province, Ginigathhena (17 km N Hatton), 31. I – 3. II. 2011, coll. N. Kluge & L. Sheyko: L / S ♀ (ZIN); Sabaragamuwa Province, Dalhausie near Sri Pada (Adam's Peak), river Seetha Gangula, 6. II. 2020, coll. N. Kluge & L. Sheyko: 1 L-S-IJ (ZIN). INDIA: Karnataka state, Udupi district, river Seethanadi near Someswar, 31. II. 2013, coll. N. Kluge & L. Sheyko: 1 L-S-IJ (ZIN); Kerala state, Kottayam district, Erumeli, 18 – 21. I. 2016, coll. N. Kluge & L. Sheyko: 2 L / SJ (ZIN); Tamil Nadu state, Madurai, river Vaigai, 10. II. 2016, coll. N. Kluge & L. Sheyko: 1 S-IJ, 1 S-I ♀ (ZIN); the same locality, 12. XII. 2022, coll. P. Srinivasan & R. Isack: 1 L-S-IJ, 1 SJ, 1 S ♀, 3 LJ, 2 L ♀ (AMC); Dindigul, Kodaikanal hills, Mangalamkombu stream, 16. II. 2020, coll. P. Srinivasan & R. Isack: 2 LJ (AMC); Theni, Suruli falls, 13. XI. 2021, coll. P. Srinivasan & R. Isack: 4 LJ (AMC). Additional descriptions Larva. CUTICULAR COLORATION: Head from brown with colorless blanks (Fig. 1) to light ochre. Pronotum from brown to ochre, with lighter ovoid sigilla; mesonotum from brown with colorless blanks to ochre with lighter and darker areas; fore protopteron from brown to ochre with indistinct lighter striation along longitudinal veins (Figs 3, 6, 9). Metanotum, thoracic pleura and certain areas of thoracic sterna from contrastingly colored with brown (Fig. 2) to nearly colorless. Legs mostly ochre or colorless; each femur at midlength with brown macula adjacent to inner margin; with (Figs 2, 27) or without (Fig. 5) contrasting brown macula at base. Tibia with brown apex of outer side; tarsus with brown apex of outer side (Figs 2, 5, 27). Abdominal terga from brown with contrasting blanks to pale ochre with diffusive blanks; submedian sigilla lighter than background; terga I – IX either all with uniform color pattern (Figs 10, 12; Müller-Liebenau & Hubbard 1985: fig. 15; Kubendran et al. 2014: figs 1 – 4), or differentiated, with different median blanks on different segments; in this case, tergum V always lighter than others or with largest unpaired median blank (Figs 4, 7, 11). Abdominal sterna from nearly colorless (Fig. 10) to brown with lighter submedian sigilla and colorless median blank adjacent to posterior margin (Figs 4, 7). Caudalii light, with brown band just distad of midlength (Figs 4, 8, 11, 12). Both forms of abdominal coloration, i. e. with the 5 th tergum lightest (Figs 4, 7, 11) and with all terga uniformly colored (Figs 10, 12) are found among larvae both from Sri Lanka and from India. Among 20 larval specimens examined, 15 male larvae have contrasting coloration with 5 th tergum lightest (Figs 4, 7, 11), and only one reared male specimen from Sri Pada has larval terga uniformly colored (as in Kubendran et al. 2014: fig. 1); all 4 female larvae have abdominal terga uniformly colored (Figs 10, 12). HYPODERMAL COLORATION: Not expressed. SHAPE AND SETATION: Described by Müller-Liebenau & Hubbard (1985) and Kubendran et al. (2014). Frons between antennae narrow, but non-carinate (Fig. 61). Scape with distolateral process (Müller-Liebenau & Hubbard 1985: fig. 6 d). Labrum dorsally with long, fine, simple setae scattered over surface; submarginal arc of setae composed of 1 + 3 long, simple setae, the first two setae after the central seta closely together (Fig. 13). Left mandible between prostheca and mola slightly convex, with minute denticles toward mola; mola without apical tuft of setae; right mandible between prostheca and mola convex; mola with apical tuft of setae (Figs 14 – 15; MüllerLiebenau & Hubbard 1985: fig. 6 e). Hypopharynx with medial tuft of stout setae well developed and short (Fig. 17). Maxillary palp with distal excavation of inner margin (Fig. 18; Müller-Liebenau & Hubbard 1985: fig. 6 g). Labium with paraglossae wide, with apical setae forming three rows; labial palp with broad distomedial protuberance of 2 nd segment and conical 3 rd segment (Fig. 16; Müller-Liebenau & Hubbard 1985: figs 6 b – c). Hind protoptera present, in female somewhat smaller than in male (Figs 19, 21, 23, 25). Legs of all three pairs: Outer side of femur with row of long, stout, blunt setae (Fig. 28) and two such apical setae; apex with short, stout, spatulate setae. Inner side of femur with pointed, lanceolate setae (Fig. 29). Femoral patch (villopore) present on middle and hind legs, vestigial or absent on fore legs. Outer side of tibia with short, blunt, spatulate, stout setae; on apex one longer, blunt, spatulate seta; inner side of tibia with stout, pointed setae (Fig. 30; Müller-Liebenau & Hubbard 1985: fig. 6 h). Outer side of tarsus with blunt, stout setae smaller than on tibia. Claw without subapical setae (Müller-Liebenau & Hubbard 1985: fig. 6 i). All abdominal terga I – X with denticles on posterior margin; denticles on anterior terga smaller and blunt (Fig. 31), denticles on posterior terga larger and pointed (Fig. 32); on tergum IX denticles behind bases of submedian setae smaller of absent (Fig. 33). Abdominal sterna I – VI without denticles; sterna VII – VIII with few spaced, wide, triangular denticles (Figs 34 – 35); sternum IX with pointed denticles; in male row of denticles interrupted by protogonostyli (Fig. 36). Paraproct with pointed denticles increasing distally (Müller-Liebenau & Hubbard 1985: fig. 6 j). All 7 pairs of tergalii present, tergalii of 1 st pair smaller than others (Fig. 4). Subimago. CUTICULAR COLORATION: Mostly light brownish (Figs 37 – 43). HYPODERMAL COLORATION: As in imago. TEXTURE: On all legs of both sexes, last tarsal segment covered with pointed microlepides; other tarsomeres covered mostly with blunt microlepides, with few pointed microlepides on distal margin (Figs 38 – 40) (Kluge 2022). Imago, male (Figs 44 – 50). Head brown. Turbinate eyes from red to yellow, widened distally. Thorax dark brown. Fore wing with membrane colorless, veins ochre. Pterostigma with incomplete oblique veins connected with costal vein, but not with subcostal vein. Hind wing narrow, without costal projection, with 2 longitudinal veins (Figs 20, 22, 24). Legs of all pairs ochre, either with red-brown band near apex of femur (Figs 52 – 53), or without it (Figs 54 – 55). Middle and hind tarsi with 2 apical spines (on 1 st + 2 nd and 3 rd segments). Abdominal terga and sterna mostly ochre or whitish; each tergum II, IV and VI with small brown or reddish spot at midline near fore margin, either without other coloration (Figs 44, 48) or with red area by sides and behind spot (Figs 45 – 47, 49 – 50; Kubendran et al. 2014: fig. 18); terga I, III and V lack this spot and red area. Gonostyli with 1 st segment parallel-sided, with prominent rectangular apical-inner angle; 2 nd segment narrow in proximal part and wider in distal part; 3 rd segment short and roundish, sharply separated (Figs 56 – 60). Penial bridge projected caudally forming pair of rounded lobes with deep concavity between them, with sharply pointed, sclerotized denticle arising from middle of this concavity; gonovectes sharply bent (Figs 56, 57, 60). Imago, female (Fig. 51). Head, thorax and abdomen ochre with brown. All tarsi with 2 apical spines (fore tarsus on 2 nd and 3 rd segments, middle and hind tarsi on 1 st + 2 nd and 3 rd segments). Wings as in male; hind wing smaller (Fig. 26). Egg. Widely oval; chorion smooth, without regular relief; one pole surrounded by fine, narrow, ring-form groove, with or without few indistinct, shallow protuberances just outside groove (Figs 62 – 64). Dimension. Fore wing length 4 mm.	en	Kluge, Nikita, Sivaruban, T., Srinivasan, Pandiarajan, Barathy, S., Isack, Rajasekaran (2023): Diagnosis, variability, distribution and systematic position of Labiobaetis pulchellus (Müller-Liebenau & Hubbard 1985) (Ephemeroptera, Baetidae, Baetis s. l.). Zootaxa 5264 (1): 94-108, DOI: 10.11646/zootaxa.5264.1.6, URL: http://dx.doi.org/10.11646/zootaxa.5264.1.6
5C6687DE5F1FB7560A8DFA2B6374F9C5.taxon	distribution	Distribution. Southern India and Sri Lanka. Synonymy of L. soldani. According to the original description, Labiobaetis soldani differs from L. pulchellus by the following characters (Kubendran et al. 2014: table 1): Submarginal bristles on labrum: « feathery » in L. soldani, « fine » in L. pulchellus. According to the original description of L. pulchellus « submarginal fine bristles single (not in a dense row) »; here the term « submarginal bristles », refers to the setae located at a distance from the distal margin and present on the drawing, on which the marginal feathery setae are not drawn (Müller-Liebenau & Hubbard 1985: fig. 6 a). According to the original description of L. soldani, its labrum « with an arc and stout setae, long and thin setae medially; distal margin bordered with setae, distolaterally 14 feathered bristles; ventrally with 4 stout, 2 long setae and distomedial arc of very thin setae ». On the drawing (Kubendran et al. 2014: fig. 8), both dorsal and ventral sides of the labrum are drawn together, and the marginal feathery setae are present as well. So different setae are reported as « submarginal bristles » in the comparison of L. soldani and L. pulchellus. Ratio of paraglossae to glossae in width: « 1.8 x » in L. soldani, « 2 x » in L. pulchellus. This difference is less than the possible accuracy of paraglossa measurement. Apex of labial palp: « slightly pointed » in L. soldani, « pointed » in L. pulchellus. Judging by the original drawings (Müller-Liebenau & Hubbard 1985: fig. 6 b; Kubendran et al. 2014: fig. 13) difference between left and right palps can be greater than between the individuals attributed to these two species. Hind wing (and hind protopteron of larva): « absent » in L. soldani, « well developed » in L. pulchellus. Actually, the presence of hind wings in L. soldani was overlooked (Kubendran, personal communication). Pointed setae on the margin of femur: « 6 » in L. soldani, « 8 » in L. pulchellus. Such variability is found on different legs of one and the same individual. Thus, no one species-specific character separating L. soldani from L. pulchellus has been reported. The unusual coloration of male imaginal abdomen, with alternating colored even segments II, IV and VI and colorless odd segments I, III and V testifies that the form described as L. soldani from India is conspecific to L. pulchellus originally described from Sri Lanka.	en	Kluge, Nikita, Sivaruban, T., Srinivasan, Pandiarajan, Barathy, S., Isack, Rajasekaran (2023): Diagnosis, variability, distribution and systematic position of Labiobaetis pulchellus (Müller-Liebenau & Hubbard 1985) (Ephemeroptera, Baetidae, Baetis s. l.). Zootaxa 5264 (1): 94-108, DOI: 10.11646/zootaxa.5264.1.6, URL: http://dx.doi.org/10.11646/zootaxa.5264.1.6
