Hydropsyche napaea Mey 1996

(Figs. 28—34)

Larva: Total length 16.0— 16.5 mm (n = 10). Overall, body shape as usual in Hydropsychidae (Fig. 28). Head and notal sclerites brown to dark brown.

Head: Head capsule length, 1.22—1.26 mm; width, 1.20—1.22 mm. Dorsum of head dark brown with yellow stripe on midline (Fig. 29). Areas around eyes light brown, muscle scars below eyes (Fig. 29). Dorsal and lateral portions of head covered with long, black, truncate peg setae and with tapered setae in anterior 3/4ths (Fig. 29). Frontoclypeus with anterior margin strongly convex medially, with yellow stripe on midline (Fig. 29). Frontoclypeus covered uniformly with truncate peg setae and tapered setae. Ventral surface of head brownish, posterolaterally with group of muscle scars (Fig. 30). Labrum brown; apically rounded in dorsal view; bearing well-developed, golden brown, pectinate, lateral setae and long, stout, dark, dorsal setae (Fig. 31). Mandibles dark brown, asymmetrical: left mandible with 2 apical teeth and 3 mesal teeth, right mandible with 2 apical teeth and 3 mesal teeth and with deep excision between middle and basal mesal teeth, outer surfaces of both mandibles with scattered setae (Fig. 32). Submentum brown, with deep anteromesal cleft, anterior margins on either side of cleft with long setae (Fig. 30). Anterior ventral apotome broadly triangular; posterior ventral apotome small, oval (Fig. 30).

Thorax: Nota dark brown (Fig. 33) covered with setae similar to those on dorsum of head. Prosternite brown, transverse, narrow, with dark band centrally; with pair of large, posterolateral sclerites (Fig. 35). Foretrochantin deeply forked (Figs. 28, 34 A). Forelegs stouter than other legs, each with femur widened dorsally in middle and with long setae on ventral margin (Fig. 34 A). Mid- and hind legs similar in size, shape, and structure; with dense setae on mesal surfaces of coxae through tarsi (Figs. 34 A, 34B). Mesosternum with one pair of single-stemmed gills and metasternum with 2 pairs of single-stemmed gills; gills each bearing approximately 58 lateral filaments.

Abdomen: Abdominal segments with dense brown, scale hair setae in various sizes (Fig. 28). Sternum I with 2 pairs of bifid-stemmed gills. Segments II—V each with one pair of median gills. Segments II—VII each with one pair of lateral gills arising from common base (Fig. 28). Sternum VIII with pair of small, triangular sclerites bearing spike-like setae. Sternum IX with pair of large, triangular sclerites. Tergum IX with small lateral sclerites (Fig. 36) and pair of large dorsal sclerites. Anal prolegs each with bent claw, spike-like setae present on dorsal and ventral surfaces (Fig. 36).

Material examined: THAILAND: KANCHANABURI Prov.: Huai U-Long, 191 m. 14°47.126' N, 098°40.589' E, 12- iv-2015, 10 larvae, 2 male pupae, 2 male adults, leg. Prommi ; CHIANG MAI Prov.: Huai Sai Lueng waterfall, 1060 m. 18°31' N, 098°27' E, 2- xii-2002, 5 larvae, 1 male adult, leg. Thamsenanupap ; same locality, 2- ii-2003, 6 larvae, 1 male pupae, 8 male adults, leg. Thamsenanupap; same locality, 2- iv-2003, 10 larvae, 1 male adult, leg. Thamsenanupap; Mae Pan stream, 750 m. 18°31' N, 098°25' E, 31 - i-2002, 3 larvae, 1 male adult, leg. Thamsenanupap; same locality, 12- viii-2002, 16 larvae, 2 male pupae, 13 male adults, leg. Thamsenanupap; same locality, 15- xi-2002, 12 larvae, 2 male pupae, 17 male adults, leg. Thamsenanupap; same locality, 22- ii-2003, 8 larvae, 13 male adults, leg. Thamsenanupap; same locality, 1- iv-2003, 18 larvae, 3 male pupae, 9 male adults, leg. Thamsenanupap .