Cheumatopsyche triangula Thawarorit, Sangpradub & Morse

Thawarorit, Kitiya, Sangpradub, Narumon & Morse, John C., 2013, Five new species of the genus Cheumatopsyche (Trichoptera: Hydropsychidae) from the Phetchabun Mountains, Thailand, Zootaxa 3613 (5), pp. 445-454 : 449

Cheumatopsyche triangula Thawarorit, Sangpradub & Morse sp. nov.

Figs. 3a–f.

Diagnosis. The male genitalia of this species are close to those of Cheumatopsyche chryseis Malicky & Chantaramongkol, 1997 , but can be distinguished by segment X in lateral view being longer, curved slightly upward and apically acute (tergum X of C. chryseis shorter, slightly angled upward and blunt), and in dorsal view with the apicomesal portion broadly triangular and apicolateral lobes not produced (tergum X of C. chryseis rounded and apicolateral lobes produced). The inferior appendages each have an apical segment that is broader than that of C. chryseis in lateral view. Also, the phallus is more curved and longer, with its apex broader basally and the apicomesal projection is not produced.

Description. (In alcohol) Head and thorax brown. Abdominal segments light brown, legs light brown. Forewings brown and hind wings light brown.

Wings: Shape and venation characteristic of genus. Male forewing length 5.0– 5.5 mm (n=10).

Male genitalia: Segment IX in lateral view with anterolateral margins convex, posterolateral margins each produced into tall, broadly rounded, setose lobe overlapping base of corresponding inferior appendage when fully retracted. Inferior appendages in lateral view nearly straight, each with apical segment broad, especially at base (Fig. 3d); in caudoventral view slightly curved, basal segment slender (Fig. 3a–b). Segment X in lateral view long, slightly curved dorsad and acute apically (Fig. 3d); in dorsal view apicomesal portion produced, broadly triangular, and apicolateral lobes not produced (Fig. 3c). Phallus curved and long, in ventral view apex broad and without apicomesal projection (Figs. 3e–f).

Etymology. Latin “triangulus (-a –um),” an adjective meaning “triangular,” to indicate the apicomesal portion of tergum X broadly triangular in dorsal view.

Holotype: Male. THAILAND: Chaiyaphum Province, Phu Khieo Wildlife Sanctuary, Tongto Stream (N 16° 24' 48.0", E 101° 34' 58.9"), elevation 795 m, 14-iii-2011, Coll. Kitiya Thawarorit, Teerasak Muakpetch, and Narumon Sangpradub (CU).

Paratypes: Same data as holotype, 5 males (KKU), 4 males (PNU).