A new species of Coenosia Meigen (Diptera, Muscidae) from Kunashir Island

A new species, Coenosia polina, is described from Kunashir – the southernmost island of the Kuril archipelago. It is related to Coenosia xanthopleura Shinonaga, 2003, described from Honshu Island, Japan.


Introduction
Among the Diptera material collected with the aid of yellow-tray traps in Kunashir Island by Igor Melnik, I found two species of Coenosia Meigen: 1 male of C. mollicula japonica Hennig, 1961 and 3 males and 1 female of an almost entirely yellowish Coenosia, which is related to Coenosia xanthopleura Shinonaga, 2003, described from Honshu Island, but clearly belongs to a new species.
Head.Eyes bare.Interocular space about 1/3 of head-width.Ground-colour brownish-yellow.Fronto-orbital plate, parafacial, gena and face densely white dusted, occiput light-grey dusted.Frontal vitta not dusted, yellow-brown in lower 2/3 and brownish-black in upper 1/3.Frontal vitta about 2.5-3 times as wide as each fronto-orbital plate.Parafacial narrow, slightly wider than diameter of anterior ocellus.Gena 1.5 times as wide as postpedicel.Frontal triangle whitish, weakly expressed, extending to level of upper frontal seta or slightly more.3 pairs of strong inclinate frontal setae, median pair distinctly weaker (one male has a fourth pair of hair-like median frontal setae), and 1 pair of reclinate orbital setae.Antenna yellow, inserted slightly above mid-level of eye.Postpedicel short, 2 times as long as wide, its tip rounded.Arista basally whitish and thickened, the longest aristal hairs almost half as long as width of postpedicel.Palpus whitish-yellow.Prementum of proboscis yellow, glossy.
Wing.Clear.Veins yellow.Costal spine not distinct.Costa continuing to vein M1+2, though very thin in last section.Cross-vein r-m placed at level or slightly beyond the point where vein R1 enters costa.Calypters and halteres white.Lower calypter only slightly projecting beyond upper calypter.
Abdomen.Entirely yellow in ground-colour.Tergites 3 to 5 each with a pair of strong lateral discals, tergite 5 also with pair of medial marginal setae.Tergites 4 and 5 each with pair of blackish-brown spots, tergite 3 with the same, but the spots only weakly distinct.
Male terminalia as shown in Fig. 2. Cercal plate small, apically bifurcate, with weak sclerotization.Female.Length: body about 3.8mm, wing about 4.1mm.Similar to male.Leg colour more dirty yellowish, so that the blackish colour of apical tarsomeres of all legs is less conspicuous than in male.All tibial setae stronger than in male.Mid tibia with strong anterodorsal.Hind tibia without long and thin posteroventral setae in apical 1/3.Habitat.All specimens were collected in yellow-tray traps which were placed at the edge of a deciduous (mostly oak) forest at almost sea level (25 m).

Diagnosis
Etymology.Th e new species is named after my daughter Polina.