Hydropsyche brontes Malicky & Chantaramongkol 2000

Prommi, Taeng On, 2016, Descriptions of larvae of four species of Hydropsyche (Hydropsychidae: Trichoptera) from Thailand, Zootaxa 4158 (4), pp. 577-591 : 581

Hydropsyche brontes Malicky & Chantaramongkol 2000

( Figs. 10–18 )

Larva: Total length 10.0–11.0 mm (n = 10). Overall body shape as usual in Hydropsychidae ( Fig. 10 ). Head yellow to dark-brown, with dark muscle scars in posterior 1/5th. Nota light-brown, each with posterolateral muscle scars.

Head: Head capsule length 1.02–1.05 mm; width, 0.85–0.94 mm. Dorsum of head dark-brown with two distinct yellow marks on frontoclypeus; T-shaped mark anteriorly and circular mark posteriorly ( Fig. 11 ). Area around each eye and posterior 1/5th of head yellow with dark muscle scars ( Fig. 11 ). Frontoclypeus with anterior margin convex, slightly crenulate, with pairs of setae #1, #2, and #3 extending beyond anterior margin ( Fig. 11 ). Head with moderately long, erect, acuminate peg setae; with brush of setae, tapered setae on dorsal and lateral regions in anterior 3/4ths. Frontoclypeus devoid of acuminate peg setae and tapered setae ( Fig. 11 ). Head ventrally dark-brown with transverse stridulatory lines arranged on either side of median suture about 3/4ths length of head capsule ( Fig. 12 ). Labrum brown; elliptical in dorsal view; bearing well-developed, lateral, golden yellow, pectinate setae and stout setae on dorsal surface ( Fig. 13 ). Mandibles dark-brown, asymmetrical, right mandible with 1 apical and 2 mesal teeth, left mandible with 2 apical and 3 mesal teeth and with well-developed mesal brush of setae ( Fig. 14 ); lateral surfaces of both mandibles with scattered setae (not shown). Submentum light-brown, with deep anteromesal cleft, anterior margins on either side of cleft with long setae. Anterior ventral apotome broadly triangular, posterior ventral apotome small, triangular ( Fig. 12 ).

Thorax: Nota brown, with posterolateral muscle scars darker. Pronotum with numerous, erect, acuminate peg setae and long, appressed scale hairs; dark muscle scars midway between midline and lateral margin in posterior half ( Fig. 16 ). Meso- and metanota with numerous, long, appressed scale hairs and scattered, erect, acuminate peg setae; posterolateral margins of meso- and metanota each with dark muscle scars ( Fig. 16 ). Prosternite brown, transverse, narrow, with broad dark band along posterior margin and with pair of large, paler, posterolateral sclerites ( Fig. 15 ). Foretrochantin deeply forked ( Fig. 10 ). Forelegs with numerous feather-like setae on posterior surfaces of coxae; trochanters with long, feather-like setae in ventral margins; femora each with row of long, dark, spike-like setae on ventral margin and few, short, dark, setae on external surface ( Fig. 17 A). Mid- and hind legs similar in size, shape, and structure; with feather-like setae on posterior surfaces of femora ( Fig. 17 B, 17C). Mesosternum with one pair of single-stemmed gills and metasternum with 2 pairs of single-stemmed gills; gills bearing approximately 28 lateral filaments.

Abdomen: Abdominal segments densely covered dorsally and laterally with dark, recumbent setae ( Fig. 10 ). 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, each arising from common base. Sternum VIII with pair of small, subtriangular sclerites bearing spike-like setae. Sternum IX with pair of large, triangular sclerites bearing spike-like setae emanating from prominent sockets. Tergum IX with small lateral sclerites ( Fig 18 ) and pair of large dorsal sclerites. Anal prolegs each with bent claw and cluster of long bristles. Venter of each anal proleg with spike-like setae on caudal lobes; outer sclerites with same setae ( Fig. 18 ).

Material examined: THAILAND: RATCHABURI Prov.: Huai Nueng stream from Phachi watershed , 140 m . 13°32.135' N, 099°17.842' E, 27-xii-2014, 14 larvae, 3 male pupae; Huai See stream from Phachi watershed , 170 m . 13°34.078' N, 099°15.495' E, 27-xii-2014, 127 larvae, 20 pupae, 5 male adults; Huai Phark from Phachi watershed , 183 m . 13°30.241' N, 099°15.889' E, 19-xii-2014, 26 larvae, 5 male pupae; Phachi Sarm stream from Phachi watershed , 123 m . 13°34.275' N, 099°21.778' E, 12-xii-2014, 12 larvae; Huai Namnak, 219 m. 13°22.563' N, 099°16.585' E, 10-v-2014, 27 larvae, 3 male pupae KANCHANABURI Pro.: Huai Kayeng, 244 m . 14°36.224' N, 098°34.822' E, 11-iv-2015, 98 larvae, 12 male pupae, 3 male adults; Huai Pakkok, 246 m. 14°39.518' N, 098°32.237' E, 12-iv-2015, 119 larvae, 16 male pupae, 2 male adults. All material leg. Prommi.

Figures

FIGURES 10 ― 15. Larva of Hydropsyche brontes Malicky & Chantaramongkol 2000: 10, larval habitus, right lateral; 11, head, dorsal; 12, head, ventral; 13, labrum, dorsal; 14, mandibles, ventral; 15, prosternum, ventral.

FIGURES 16 ― 18. Larva of Hydropsyche brontes Malicky & Chantaramongkol 2000: 16 A, pronotum, dorsal; 16 B, mesonotum, dorsal; 16 C, metanotum, dorsal; 17 A, right pleuron, foretrochantin (arrow), and foreleg, right posterolateral; 7 B, right midleg, right posterolateral; 17 C, right hind leg, right posterolateral; 18, sterna VIII and IX and anal prolegs, ventral.