Dolichopus planitarsis

Barkalov, Anatolii V., Negrobov, Oleg P. & Ya, Igor, 2009, The Dolichopus planitarsis species group in the Palearctic Region with the description of a new species from the Russian Altai (Diptera: Dolichopodidae), Zootaxa 2268, pp. 59-64 : 60

Dolichopus planitarsis species group

Diagnosis. Size 4.5–7 mm. The planitarsis species group differs distinctly from all other Palearctic Dolichopus , first of all, in male mid tarsomere 5 being black, flattened dorsoventrally, bearing anterior and posterior rows of strong setae. Postocular setae entirely black. Face gradually narrowing downward. Antennomeres often elongate; antennal stylus usually shifted anteriad. Femora partly black and partly yellow; fore and mid femora often mostly yellow; hind femur usually black except apex (but entirely yellow in D. tundrensis sp. nov.). Mid and hind femora with one preapical anterior bristle. Male fore tarsus usually simple, with neither flattened, nor widened segments (but remarkably setose in D. bonsdorffi ); mid tarsus simple except 5th segment. Hind tarsus with at least 2, usually 3 dorsal bristles. Wing longer than body, with weak but distinct thickening at apex of R1. M1+2 moderately sinuate, without stubvein. Wing anal lobe poorly developed, and anal angle obtuse or absent in male. Cercus ovate, serrate at apex, with falcate marginal setae.

The combination of character states is distinctive to planitarsis species group, but most of them may also occur in Dolichopus annulipes group s.lat. However, Palearctic species of the other groups of Dolichopus have never so remarkably modified 5th segment of mid tarsus (apomorphy), and members of the related annulipes group s.lat. always have simple mid tarsus. The shifted anteriad antennal stylus and poorly developed wing anal lobe distinguish the planitarsis species group from the annulipes lineage, supporting the monophyly of the former.