Adapted from Vockeroth (1990).
MALE.
Very similar to male of Platycheirus amplus, differing as follows:
Antenna usually mostly orange with basoflagellomere brown on upper half or less; scape and pedicel brownish above or throughout in some specimens and basoflagellomere brown on about upper two-thirds. Scutum with only pale pile in some specimens. Scutellar pile usually entirely pale, rarely some black pili present near margin. Dorsal half of anepimeron with moderately dense tuft of upwardly directed pale brown pili; lower half of anepimeron bare. Longest pili of lower part of katepisternum from one-sixth to half length of arista. Wing membrane rather extensively bare; cell bm broadly bare basally and bare medially on from half to five-sixths its length. Halter capitulum yellow to brown. Legs usually paler; pro- and mesofemora and first tarsomere of metaleg usually entirely yellow orange. Protrochanter with ventral black setae about half as long as basal diameter of femur. Mesotibia with anteroventral pile tuft on basal half subappressed, usually entirely pale, short, with longest pili about 1.5 times as long as tibial diameter; pile of posterior surface yellow to brown. Mesotibia with setae of anterior surface moderately dense, rather fine; longest setae about half as long as tibial diameter; first tarsomere of metaleg moderately swollen on about basal one-third, tapering evenly to rather slender apex.
FEMALE.
Not distinguishable from females of several related species.
Platycheirus (Platycheirus) nearcticus Vockeroth, 1990.
Vockeroth, J.R. (1990) Revision of the Nearctic species of Platycheirus (Diptera: Syrphidae). The Canadian Entomologist 122, 659-766.
Nearctic species that occurrs from Yukon to Newfoundland, south to Oregon, New Mexico and North Carolina.
unless otherwise stated