Claustropyga stupenda Hippa & Vilkamaa, 2016, sp. n.

Claustropyga stupenda sp. n.

Figs 4 A–D

Material studied. Holotype male. CANADA, Yukon Territory, Ogilvie Mts., North Fork Pass, 4300 ft, 19.vi.1962, R.E. Leech (in CNC). Paratypes. CANADA, Yukon Territory, North Fork Crossing, Mi. 43, Peel Plt. Rd, 3500 ft, 4.vii.1962, P. J. Skitsko (1 male in MZH); RUSSIA, Yamalo-Nenets Autonomic Region, on the river Longotegan, 67, 32°N, 66,72°E, Malaise trap, 2-28.vii.2015, A. Barkalov (1 male in MZH).

Male. Colours faded in the specimens studied. Head. Eye bridge 2 facets wide. Face with 6–10 scattered longer and shorter setae. Clypeus non-setose. Maxillary palpus with 3 segments; segment 1 longer than segment 2, segment 3 shortest; segment 1 with 1 long sharp seta, with a dorsal group of sensilla; segment 2 with 1 long sharp seta and 2–4 shorter truncate setae, segment 3 with 4–5 short truncate setae. Body of antennal flagellomere 4 2.4 x as long as wide, the neck shorter than broad, the longest setae as long as the width of flagellomere. Thorax. Anterior pronotum with 2–3 setae. Episternum 1 with 6–7 setae. Wing. Length 2.5–2.7 mm. Width/length 0.40. R1/ R 0.70. c/ w 0.70 –0.80. r-m and bM non-setose. Halter pale brown. Legs. Front tibial organ with vestiture in small patch. Front tibial spur slightly longer than the tibial width. Abdomen. Setae rather short. Hypopygium (Figs 4 D). Intercoxal area with two small lobes, medially as long as gonocoxite at base of gonostylus; gonocoxa slightly longer than gonostylus, with normal setosity; gonostylus (Figs 4 A–C) laterally rounded, swollen, medially strongly concave, with short setosity, bearing a slender apical tooth, 1 short apical, and 1 short dorsal megaseta in a medial position and a pair of very long curved medial megasetae arising from a common basal body. Tegmen long and narrow, with blunt tooth-like lateral lobe on apical half, the extreme apical part narrowing.

Female. Unknown.

Discussion. Claustropyga stupenda is unique in the genus in having two enormous medial megasetae on its gonostylus, superficially resembling the large megasetae present in the gonostylus of many species of Keilbachia Mohrig, 1987. From these, C. stupenda is distinguished at once by the large ventral intercoxal lobe, typical of Claustropyga. Concerning the other species of Claustropyga, C. stupenda slightly resembles C. brevichaeta (Mohrig & Antonova). In C. brevichaeta, the megasetae homologous to the elongated medial megasetae on the gonostylus in C. stupenda can be distinguished even if they are not greatly enlarged, and the tegmen is similar even if short (Fig. 4 D; Hippa et al. 2003: figs 8 d–f). By its elongated tegmen, C. stupenda resembles C. clausa (Tuomikoski) and C. lobigera, but otherwise the species are not especially similar.

Etymology. The name is Latin, stupenda astonishing, referring to the astounding structure of the hypopygium of the species.