Platycheirus orarius Vockeroth, 1990:720

Adapted from Vockeroth (1992).

MALE.

Very similar to male of Platycheirus immarginatus, differing as follows:

Thoracic pile entirely pale except some stiff black pili present on lower part of katepisternum in some specimens; posterior part of anepisternum with pile moderately dense, uniform, with scarcely crinkly apices; upper part of katepisternum with at least 12 pili. Legs yellow-orange with coxae, pro- and mesotrochanters, first and last two tarsomeres of metaleg, and obscure marks on metatibia in some specimens dark brown to black; second and third tarsomeres of metaleg brown above in some specimens but distinctly paler than last two tarsomeres. Protrochanter with yellow ventral setulae very short; profemur without posterior subbasal tuft of pale pili, with many rather long straight posterior and ventral yellow pili; row of three or four posterior pili longer and stronger than in P. immarginatus and with one or two black in some specimens; cluster of several longer subbasal ventral pili black; protibia with posteroapical angle slightly more acute; first protarsomere a little more abruptly widened beyond base, reaching its maximum width at about two-fIfths its length rather than beyond mid length; second tarsomere slightly longer than wide. Mesofemur anteroventrally usually with irregular group of weak black setae at mid length followed by sparse fine wavy black pili about 1.5 times as long as femoral diameter, ventrally with long pili of which some black and slightly stronger. Mesotibia with dense, very crinkly, mostly yellow pile, about as long as tibial diameter, on almost all anteroventral, ventral, and posteroventral surfaces.

Abdomen as in paler specimens of P. immarginatus but with slightly wider median black vitta. Surstylus with very large dorsobasal lobe.

FEMALE.

Not distinguishable from females of several similar species.

Platycheirus (Platycheirus) orarius Vockeroth, 1990.

Vockeroth, J.R. (1990) Revision of the Nearctic species of Platycheirus (Diptera: Syrphidae). The Canadian Entomologist 122, 659-766.

Body lenght: 7.9-9.6 mm.