Trichocoelina dispansa, Vilkamaa & Menzel, 2019

Vilkamaa, Pekka & Menzel, Frank, 2019, Re-classification of Lycoriella Frey sensu lato (Diptera, Sciaridae), with description of Trichocoelina gen. n. and twenty new species, Zootaxa 4665 (1), pp. 1-67 : 23

Trichocoelina dispansa sp. n.

Figs 4 A , 6 A , 18 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) . Paratype. RUSSIA, same data as holotype (in MZH) .

Description. Male. Head. Face and antenna concolorous darkish brown, maxillary palpus pale yellowish. Eye bridge 2–3 facets wide. Face with 21–22 setae. Clypeus with 1–2 setae. Maxillary palpus with 3 segments, 1 st segment as long as 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 1.8–1.9x 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 8 setae. Proepisternum with 10 setae. Scutellum with 3 longer and some short and fine setae. Wing. Fumose. Length 1.9–2.0 mm. Width/length 0.45. Anal lobe weak. Veins distinct. c/w 0.60. R 1 /R 0.70–0.85. stM shorter than fork of M. bM non-setose, r-m with 3 setae or non-setose. Halter yellow. Legs. Yellow, coxal setae pale. Fore tibial organ forming a large patch of setae in depression. Fore tibial spur longer than the tibial width. Abdomen. Pale brown, setae pale, fine and moderately long. Hypopygium ( Fig. 4 A ). Brown, as abdomen. Intergonocoxal area rather long, basally with strongly sclerotized medial stripe, with a large subtriangular apically bifid setose lobe ( Fig. 18 B ). Gonocoxa narrow, longer than gonostylus, medial margin basally smoothly curved. Gonostylus ( Fig. 6 A ) long, apically tumid, strongly impressed; densely setose on apical third; with a rather long apical tooth, with 2 megasetae subapically near the apical tooth and 2 or 3 at a medial position, megasetae long and slender, with distinct basal bodies; with 1 well-differentiated whiplash setae on ventromedial margin. Tegmen broader than long, apically and laterally roundish, sclerotized, aedeagal teeth not detectable in the specimens studied. Aedeagal apodeme long.

BIN. Unknown.

Discussion. Trichocoelina dispansa sp. n. resembles T. chentejensis (Menzel, 1992) , T. dividua sp. n., T. ithyspina sp. n., T. jukkai sp. n. and T. planilobata sp. n. in having a long apical tooth and 5–6 rather long gonostylar megasetae, some of which are positioned apically and/or subapically near the apical tooth, directed nearly perpendicularly, and partly more basal in position, directed more obliquely. Trichocoelina dispansa differs from all others in having a broader gonostylus, a distinctly broader tegmen and a shorter intergonocoxal area. Trichocoelina planilobata can be distinguished from other species of this group in having one very broad intergonocoxal lobe, medially only slightly notched, one gonostylar megaseta distinctly on the apical side of the tooth and the gonostylus impressed only on the apical half. Of the four other species in this group, T. chentejensis and T. ithyspina have long bodies of antennal flagellomeres (4 th flagellomere about 2.8–2.9x as long as broad versus 2.0x and ca 2.1–2.3x as long as wide in T. dividua and T. jukkai ). T. jukkai differs from the other remaining species in its at most very slightly apically divided medial intergonocoxal lobe and its apically roundish, not truncate, tegmen. T. jukkai differs from T. dividua further in having a more slender and more sparsely setose gonostylus, with weaker megasetae. T. dividua differs further from T. chentejensis in its longer gonostylar megasetae, and its longer and narrower tegmen and intergonocoxal lobes. T. ithyspina differs from T. chentejensis in having a long, apically bifid intergonocoxal lobe instead of two separate lobes. By the arrangement of the gonostylar megasetae, Trichocoelina obesula resembles all the species above, but differs distinctly in having a much broader gonostylus.

Etymology. The name is Latin, dispansa , spread, referring to the broad intergonocoxal lobe of the hypopygium.

Figures

FIGURE 4. Hypopygium, ventral. A. Trichocoelina dispansa sp. n. (holotype). B. T. dividua sp. n. (holotype). Scale 0.1 mm.

FIGURE 6. Gonostylus, ventral. A. Trichocoelina dispansa sp. n. (holotype). B. T. dividua sp. n. (holotype). C. T. hians (holotype). D. T. imitator (holotype). Scale 0.1 mm.

FIGURE 18. Intergonocoxal lobes of hypopygium, ventral. A. Trichocoelina aemula (holotype). B. T. dispansa sp. n. (paratype). C. T. ithyspina sp. n. (holotype). D. T. jukkai sp. n. (paratype). E. T. planilobata sp. n. (holotype). F. T. semusta sp. n. (holotype). Scale 0.05 mm.