Hydropsyche shillonga Oláh & Barnard, 2008

Oláh, J. & Johanson, K. A., 2008, Generic review of Hydropsychinae, with description of Schmidopsyche, new genus, 3 new genus clusters, 8 new species groups, 4 new species clades, 12 new species clusters and 62 new species from the Oriental and Afrotropical regions (Trichoptera: Hydropsychidae), Zootaxa 1802, pp. 1-248 : 150-152

Hydropsyche shillonga Oláh & Barnard , new species

Fig. 256–260

This species is similar to H. briseus Malicky & Chantaramongkol from Nepal, and shares with it presence of robust, apicoventral, setose processes on segment X, robust harpagones, and a pair of anteriorly directed lobes on the apical lobe of the phallotheca. Hydropsyche shillonga is easily distinguished from H. briseus by the capitate apex of the harpagones, the straight-cut apical lobes of segment IX, and the long, tapering and anterad orienting lobes on the apical lobe of phallotheca. Furthermore, the dorsolateral membranous endothecal lobes are robust, while slender in H. briseus .

Male. Body and wings brown, with light pubescence. Forewing membranes uniformly light brown. Sternite V with processes as long as one-third the segment length. Maxillary palp formula I-(III, IV)-II-V, segment V as long as sum of segments I–IV. Head dorsum light brown, with 9 setal warts of same light colour. Swollen setal wart present on proepisternum. Pretarsal claws asymmetrical, laterally flanked by setal bundle; some setal bundles present only on foreleg. Spur formula 244. Protibiae with posteroapical spur almost equal to anteroapical spur.

Wings. Forewing venation typical for the genus, except Sc and R confluent before costa, and median cell open in hind wing. Forewing crossveins m-cu and cu separate. Cu2 and A separate. Hind wing Sc and R meeting before costa about at crossvein r. Stem of M and Cu1 close. Fork 1 present. Forewing length 6.5 mm, hind wing length 5.0 mm.

Male genitalia. Abdominal segment IX fused annularly, short ( Fig. 256). Median keel short, wide parallelsided ( Fig. 257) with granulose dorsal and lateral surfaces; Anterior margins of segment IX arciform, gradually sloping dorsally, abruptly deepen ventrally; ventrum very short; sternum about 2 times longer than ventrum ( Fig. 256). Antecosta well developed, widens before margin ( Fig. 256). External groove of antecostal suture present. Apical lobe on posterolateral margins short, straight cut, almost rectangular ( Fig. 256). Posterior spine row intermittent, present on keel slope and apical lobes, absent between. Depression between segments IX and X completely filled, giving almost straight horizontal line with apicodorsal setose lobes of segment X, with very shallow, short concavity in lateral view ( Fig. 256). Body of segment X large, nearly quadrangular ( Fig. 256, 257), dorsal margin short, ventral margin long ( Fig. 256). Lateral setose areas (preanal appendages) located centrally on lateral sides of segment X, representing compact, less pigmented, elongated, ovoid, setose areas and scattered groups of posterior setae behind light, setose window; group of setae not shifted to distal margin of segment X. Apicoventral setose lobes arising from dorsum of segment, sinuous, directed ventrad; half as long as segment length; broad and robust with dilating apex ( Fig. 256, 257); ventrocaudal corners producing; longitudinal fossula running dorsad, ending in bulged, bilobed apex clearly visible in dorsal view ( Fig. 257). Dorsal interlobular gap long, narrow, surrounded by apicoventral lobes; sharply triangular at bottom; closed by both apices of apicoventral lobes. Apicodorsal setose lobes located at mid-length of dorsum, forming fused pair of circular setose ridges of double crest, with smooth, central narrow depression. Smooth cavity on anterolateral area of segment X very deep; clearly visible in dorsal view ( Fig. 257). Rim of cavity anteriorly surrounded by transverse sutures, and posteriorly by posterior rim of segment IX, and by longitudinal sutures located below and encircling smooth cavity. Coxopodites with apices reaching apex of segment X ( Fig. 256), robust, slightly S-shaped ( Fig. 256); nearly straight in ventral view ( Fig. 258). Harpagones slightly curving dorsomesad, clearly clavate ( Fig. 256, 258). Phallic apparatus double sinuate, forming long tube of same diameter along its length ( Fig. 259); phallotremal sclerites heavily pigmented, double rounded, exposed; apical lobe narrow; at phallotremal sclerites tube constricted strongly in ventral view ( Fig. 260); followed by sclerotized, apical phallothecal lobe with single apical hole hiding eversible membrane with cluster of longer spines. Apical lobe of phallotheca produced anteriorly into pair of long, tapering processes visible in lateral and ventral view. Dorsolateral membranous endothecal lobe short, apically broad with small dorsad directed slightly curving spine arising behind phallotremal sclerites. Endophallus filling almost entire horizontal section of phallotheca anteriorly of phallotremal sclerites; narrowing suddenly to gonopore.

Holotype male: INDIA: Assam, Shillong , ix–x.1918 [ T. B. Fletcher Coll.] (Brit. Mus. 1936-643, NHML, in alcohol).

Distribution. India (Assam).

Etymology. shillonga , derived from the type locality, Shillong, in the Indian Assam Province.