About Syrphus ribesii (Linnaeus, 1758)
Description: Adult Syrphus ribesii are very similar in appearance to Syrphus vitripennis and Syrphus torvus. Females can be distinguished from both species by having entirely yellow hind femora, and from S. torvus by having no hairs on their eyes. Unlike S. torvus, males also have bare eyes, but are extremely similar to S. vitripennis, differing only by having some black hairs on the hind femur and having the second basal cell of the wing entirely covered by microtrichia. The male genitalia and the larva of S. ribesii have been described. The frons, posterior to the lunulae, is shiny black. Sternites have both lateral and median black marks. The third femur of males is black for its basal two-thirds, while the third femur of females is entirely yellow. The lateral margins of the tergites are black, except at the ends of the yellow bands. Distribution: In the Palearctic realm, S. ribesii occurs from Fennoscandia south to Iberia and the Mediterranean basin, from Ireland eastward through Europe into Turkey, European Russia and Afghanistan. It also ranges from the Urals to Siberia and the Russian Far East, reaching the Pacific coast (Kuril Isles) and Japan. In the Nearctic realm, it occurs from Alaska southward to Central USA, and is present across the United States and Canada. It is highly migratory.
