Taxonomic notes on the genus Hydrobaenus with description of H. simferopolus sp. nov. from Crimea (Diptera: Chironomidae)

Abstract: A new species of the genus Hydrobaenus Fries, 1830, H. simferopolus sp. nov. (Diptera: Chironomidae: Orthocladiinae), is described based on adult male collected in the Crimean Penisula (Ukraine). Main distinguishing characters are: anal point cup-shaped with a small nose-like apex; virga composed of 3 strong equal spines; inferior volsella consisting of 2 lobes (proximal one broadly planned and covered with curved setae, distal one large nose-like and bare). A new combination of Parorthocladius korneyevi Baranov, 2011 for H. korneyevi (Baranov, 2011) comb. nov. is provided with additional differentiating characters found in male adult including: tergite IX with a median dorsal crest; anal point long, drop-like, covered with setae and ending with thumb-shaped apex; virga composed of 6–8 subequal thin long spines; inferior volsella with 2 unequal lobes (proximal one spherical and much larger); gonostylus massively bulbous and densely covered with long and short setae, crista dorsalis consists of a subapical strong tooth-like, smooth and orally projecting ridge. The male adults of both H. dentistylus Moubayed, 1985 and H. lugubris Fries, 1830 are also illustrated, diagnosed and shortly redescribed with some main distinguishing and supplementary characters. Remarks and comments on the taxonomic position, ecology and geographical distribution of the four Hydrobaenus species are given.

Key words: Diptera, Chironomidae, Hydrobaenus simferopolus sp. nov., Hydrobaenus korneyevi, new combination, new species, Ukraine, Palaearctic Region