Hydropsyche khaonanensis, Suwannarat & Malicky & Laudee, 2020

Suwannarat, Nannaphat, Malicky, Hans & Laudee, Pongsak, 2020, Four new species of caddisflies (Trichoptera: Polycentropodidae, Psychomyiidae Hydropsychidae, Odontoceridae) from Khao Nan and Tai Rom Yen National Parks, southern Thailand, Zootaxa 4801 (3), pp. 577-583 : 580-581

Hydropsyche khaonanensis n. sp. Malicky & Suwannarat

Figs. 3 A–3E

Type material. Holotype male ( PSUNHM). Thailand, Tai Rom Yen National Park , Dad Fah waterfall 3, 8 o 50’N, 99 o 19’E, 911 m, 22.iv.2018, leg. Nannaphat Suwannarat.

Paratype: 1 male, Thailand, Kao Nan National Park, Klong Gray river 5, 8 o 45’N, 99 o 32’E, 1132 m, 6.iv.2018, leg. Nannaphat Suwannarat ( PSUNHM) .

Etymology. The species is named for the type locality, Khao Nan National Park.

Description. The whole insect is yellowish grey with comparatively dark eyes. Length of each forewing 8–10 mm (n = 2).

Male genitalia ( Figures 3 A–3E). In dorsal view ( Fig. 3A ), segment IX forming isosceles trapezoid with Ushaped incision for one-third of its length anteriorly; posterior part of segment IX fused with segment X at shallow M-shaped line of fusion; lateral lobes of segment IX triangular and acute apically; in lateral view ( Fig. 3B ), segment IX C-shaped with anterolateral margins convex; posterior margins of segment IX setose; in ventral view ( Fig. 3C ), segment IX subrectangular with anterolateral lobes. Segment X in dorsal view ( Fig. 3A ) short with numerous of setae, posteromesal margin with 2 pointed processes; in lateral view ( Fig. 3B ), segment X somewhat triangular, beak-like posteriorly. Inferior appendages slender and long, each with basal segment slender and more than twice as long as apical segment; apical segment slender and short, apex rounded and slightly upturned in lateral view; in ventral view, inferior appendages tubular, slightly curved inward ( Fig. 3C ). Phallus axe-shaped, expanded and downcurved basally, apicodorsal end abruptly truncate and apicoventral portion curved caudad and pointed in lateral view ( Fig. 3D ).

Diagnosis. The phallus of H. khaonanensis n. sp. is similar to that of H. arcturus Malicky & Chantaramongkol 2000 , but a clear difference is seen in the ventral view of the phallus ( Figs. 3E, 3F ); the two distal lateral lobes have rounded outer edges in H. khaonanensis n. sp. (3E), but in H. arcturus these lobes have short distal points which are directed outward ( Fig. 3F ).

Figures

FIGURES 3A–3F. Male genitalia of Hydropsyche spp. 3A–3E, H. khaonanensis n. sp.: 3A, dorsal; 3B, left lateral; 3C, ventral; 3D, phallus, left lateral; 3E, phallus apex, ventral. 3F, H. arcturus, phallus apex, ventral. A Inf = apical segment of inferior appendage (paired), B Inf = basal segment of inferior appendage (paired), Inf = inferior appendage (paired), Seg IX = abdominal segment IX, Seg X = abdominal segment X.