Trichocoelina absidata sp. n.

Figs 1 A, 3 B

Material studied. Holotype male. RUSSIA, Krasnoyarsk region, Taimyr Peninsula, 12.5 km S of Dixon, 73°24’N, 80°39’E, on the river Lemberova, pan trap, 7–10.VII.2012, A. Barkalov (in ISEA).

Description. Male. Head. Face and antenna concolorous brown, maxillary palpus pale yellow. Eye bridge 3 facets wide. Face with 18 fine setae. Clypeus with 3 setae. Maxillary palpus with 3 segments, 3 rd segment longer than 1 st segment, 2 nd segment shortest; 1 st segment with 2 or 3 setae, with a dorsal patch of sensilla; surface of antennal flagellomeres smooth, body of 4 th antennal flagellomere 2.3x as long as wide, the neck shorter than broad, the longest setae slightly shorter than the width of flagellomere. Thorax. In poor condition in the specimen studied. Brown, setae pale. Wing. Fumose. Length 2.6 mm. Width/length 0.40. Anal lobe moderate. Veins distinct. c/w 0.60. R 1 /R 0.70. stM and fork of M subequal in length. r-m 2x as long as bM, r-m and bM non-setose, Halter yellow. Legs. Yellow, coxal setae pale. Fore tibial organ forming a large patch of fine setae in depression. Fore tibial spur slightly longer than the tibial width. Abdomen. Pale brown, setae pale, short and fine. Hypopygium (Fig. 1 A). Brown, as abdomen. Intergonocoxal area long, with two short but distinct setose lobes. Gonocoxa broad, longer than gonostylus, medial margin basally smoothly curved, with short sparse setosity. Gonostylus (Fig. 3 B) broad, apically slightly narrowed, medially strongly impressed; with short setosity, with a long apical tooth, with about 15 megasetae medially, megasetae rather long and slender; with 2 well-differentiated whiplash setae on ventromedial margin. Tegmen subconical, weakly sclerotized, with a small area of minute aedeagal teeth. Aedeagal apodeme long.

BIN. Unknown.

Discussion. In the form of its gonostylus, Trichocoelina absidata sp. n. most resembles T. dicksoni sp. n. and T. hians sp. n. It differs from T. dicksoni in having a longer apical tooth of gonostylus and shorter and more numerous gonostylar megasetae, in its more conical and unsclerotized tegmen which is not subtriangular and laterally and apically sclerotized, and in having shorter intergonocoxal lobes of the hypopygium. It is similar to T. hians in having numerous short gonostylar megasetae, but differs in its basomedially less bulged gonostylus, in missing the narrowed apical part of the tegmen and in having short intergonocoxal lobes of hypopygium.

Etymology. The name is Latin, absidata, hollowed, referring to the strongly recurved gonostylus with an impressed medial side.