Hydropsyche tanua 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 : 68-69

Hydropsyche tanua Oláh & Barnard , new species

Fig. 99–102

This species is similar to H. tanung , new species, differing in details in segments IX and X. In H. tanua the apical lobe on segment IX is dorsally triangular, not straight cut, round sub-quadrangular as in H. tanung ; and the apicodorsal lobes on segment X are smaller in H. tanua than in H. tanung . Hydropsyche tanua is easily identified also by the presence of spiny structures on the membranous endothecal processes. The paired spines connected to the phallotremal sclerites are long, slender and curving distad, while short, stout and curving basad in H. tanung . Furthermore, the spines on the dorsolateral, membranous endothecal process are long and straight, not short and curving. The forewing nygma is darkly pigmented, easy to differentiate from that in H. tanung . Moreover, its forewing membrane has no pattern, while H. tanung forewing membrane has pale spots. Male. Small sized, brown. Forewing membrane uniformly brown, nygma dark. Maxillary palp formula I-II- (III, IV)-V, segment V as long as segments I–IV combined. Head dorsum brown, with 9 brown setal warts. Anteromesal setal wart mesally divided into 2 warts. Swollen setal wart present on proepisternum. Pretarsal claw asymmetrical, laterally flanked by setal bundle. Spur formula 244. Posteroapical spur on protibia smaller than anteroapical spur.

Wings. Venation typical for the genus. Forewing crossveins m-cu and cu separate. Sc and R, and Cu2 and A separate before costa. Hind wing Sc and R meeting before costa about at crossvein r. Stem of M and Cu1 close. Median cell close. Fork 1 present. Forewing length 6.0 mm, hind wing length 5.0 mm.

Male genitalia. Abdominal segment IX fused annularly. Median keel almost as broad as long ( Fig. 100), dorsal surface granulose, lateral surfaces glabrous; keel occupying entire dorsum IX shifted posterad; anterior margin arciform, dorsum located more posteriorly than ventrum, resulting in short ventrum and slightly longer dorsum ( Fig. 99). Antecosta well developed, forming double, dorsally narrowing line almost reaching keel before margin; with external groove of antecostal suture; apical lobe on posterolateral margins long, parallelsided, with obliquely cut apex; dorsal corner longer. Posterior spine row intermittent, present on median keel slopes and on apical lobes, absent between. Depression between segments IX and X stepwise, delineated by distal end of median keel and by humps of apicodorsal setose lobes. Body of segment X roundedly triangular in lateral view ( Fig. 99); roundedly quadrangular in dorsal view ( Fig. 100). Lateral setose areas (preanal appendages) located distally on segment, forming compact, ovoid, pale patch and scattered setae in more distal position towards distal margin of segment X. Apicoventral setose lobe modified into pair of long, slender processes with apical setae ( Fig. 99, 100); almost straight in lateral view; straight and slightly oriented mesad due to broadening apex in dorsal view. Dorsal interlobular gap widely ovoid; demarcated by slender, apicoventral setose lobes; anterior base of gap concave. Apicodorsal setose lobe forming pair of short processes shifted anteriorly to intersegmental depression. Smooth cavity on segment forming slightly elongate, circular, shallow depression dominating on basal half of body of segment X. Longitudinal sutures encircling shallow cavity present anteroventrally. Coxopodites reaching apex of apicoventral processes; slender, slightly curving dorsad ( Fig. 99), dilating at distal one-third. Harpagones tapering in lateral and ventral view ( Fig. 99, 101). Phallic apparatus ( Fig. 102) simply bent; broadening almost triple along ventrad curving basal section; horizontal section of phallotheca slender, curving ventrad at mid-length. Endophallus forms well pigmented, narrow tube, reaching phallic apparatus bend. Phallotremal sclerite flat in lateral view, triangular, with tapering distal end in dorsal view; pair of long, thin, distally curving spines at phallotremal sclerites. Sclerotised spine on tip of dorsolateral membranous endothecal process slender, almost straight. Additional single, dorsomedian, membranous endothecal process with stout spine present on mid-length of phallotheca. Apical membranous endothecal process with pair of short, stout spines.

Holotype male: MALAYSIA: North Perak, Belum Expedition , 14.vi.1994, Rothamsted light trap 2 [B. Hellmund] ( NHML, alcohol).

Paratypes: same data as holotype — 4 males ( NHML) ; ditto, except ii.1994, Rothamsted light trap 2 [M. Erle] — 2 males ) depository); ditto, except Temegor Lake , Belum Expedition, ix–x.1993 [G.S. Robinson] — 1 males ( OPC) ; ditto, except 13.xii.1993 — 8 males ( NHML) .

Distribution. Malaysia (Perak).

Etymology. tanua , derived from the Hydropsyche species name tanung , a very similar species to H. tanua .