Sphegina quadrisetae

The name comes from Latin 'quad', meaning 'four', referring to the four long black setae on its scutellum at posterior margin.[2]

In female specimens, the body length is 6.9 millimeters and the wing length is 7.2 millimeters. The face is concave, unusually strongly projected antero-ventrally, with the frontal prominence very strongly developed. The head is entirely black; the face is yellow with long, soft hairs along the eye-margin; occiput dark brown; antenna dark brown with black setae dorsally on scape and pedicel; thorax black; scutellum black and subtriangular; legs yellow; all tarsi and apical ⅓ of metatibia black. The metatibia is without apicoventral dens, the metafemur is very weakly incrassate, and the metatarsus has a very thin basal tarsomere. A narrow fascia posterior of the lunula is non-pollinose and shiny. The basal flagellomere is slightly oval, and the arista is almost three times as long as the basal flagellomere and covered in long, soft hairs.[2]