Trichocoelina nefrens Vilkamaa & Menzel 2019, sp. n.

Trichocoelina nefrens sp. n.

Figs 11 A, 13 B, 17 E

Material studied. Holotype male. RUSSIA, Krasnoyarsk region, Taimyr Nature Reserve, Aru-Mas, 72.50°N, 101.94°E, pan trap, 9–20.VII.2010, A. Barkalov (in ISEA). Paratypes. RUSSIA, same data as holotype, 2 males (in MZH); Krasnoyarsk region, Taimyr Peninsula, on Zakharova River, Rassokha, 72.70°N, 101.08°E, pan trap, 1–10.VII.2011, A. Barkalov, 2 males (in MZH, SDEI); Krasnoyarsk region, Taimyr Nature Reserve, VII.2010, A. Barkalov, 1 male (in ISEA).

Description. Male. Head. Face brown, antenna darker brown, maxillary palpus pale yellowish. Eye bridge 2–3 facets wide. Face with 24–26 fine setae. Clypeus with 2–3 setae. Maxillary palpus with 3 segments, 1 st segment longer than 3 rd segment, 2 nd segment shortest; 1 st segment with 1–2 setae, with a dorsal patch of sensilla; surface of antennal flagellomeres smooth, body of 4 th antennal flagellomere 1.95–2x as long as wide, the neck shorter than broad, the longest setae slightly shorter than the width of flagellomere. Thorax. Brown, setae pale. Anterior pronotum with 4–7 setae. Proepisternum with 6–8 setae. Scutellum with 4 longer and some short and fine setae. Wing. Fumose. Length 2.0– 2.2 mm. Width/length 0.40. Anal lobe weak. Veins distinct. c/w 0.65–0.75. R 1 /R 0.50–0.60. stM slightly shorter than fork of M. r-m longer than bM, bM non-setose, r-m with 3–4 setae. Halter yellow. Legs. Yellow, coxal setae pale. Fore tibial organ forming a dense patch of fine setae in depression. Fore tibial spur slightly longer than the tibial width. Abdomen. Pale brown, setae pale and fine. Hypopygium (Fig. 11 A). Brown, as abdomen. Intergonocoxal area long, with 2 distinct narrow setose lobes. Gonocoxa broad, as long as gonostylus, basally with strongly sclerotized medial stripe, medial margin basally smoothly curved, with short sparse setosity. Gonostylus (13 B) broad, laterally roundish, apically strongly curved and narrowed, dorsally forming a lobe; strongly impressed; with short setosity, without apical tooth, with one dorsal and two ventral subapical megasetae and a group of three ventral and six dorsal megasetae subbasally, megasetae slightly curved and on distinct basal bodies; with 1 weakly differentiated whiplash seta on ventromedial margin. Tegmen (Fig. 17 E) much longer than broad, conical with sharp apex, with sharp lateral corners, sclerotized, with area of very tiny aedeagal teeth. Aedeagal apodeme long.

BIN. Unknown.

Discussion. Trichocoelina nefrens sp. n. differs from all other known species of the genus in lacking the apical tooth and in the peculiar form of the gonostylus. See also under T. magnifica sp. n.

Etymology. The name is Latin, nefrens, toothless, referring to the lack of the apical tooth on the gonostylus.