Ento Photo File

Here's a hoverfly that I couldn't identify. It's a female Syrphus sp. and one of three look-a-like species. Telling apart Syrphus torvus, S. ribesii and S. vitripennis can be troublesome at times but not always impossible. Syrphus torvus, for instance is the only one that has hairy eyes. This is quite visible in males, females are less obvious, so you probably have to catch them and look into their eyes from various angles. The other two Syrphus species are hard to tell apart, especially the males. For females there is a clue though: if the thighs are blackish it is Syrphus vitripennis, the smallest of the three. If the thighs are yellow it is Syrphus ribesii, the biggest of the three. Unfortunately although I took six photos of this hoverfly, none showed the rear femur, so I don't know if it was black or yellow. The larvae of all species feed on aphids.