Monday, 31 August 2015
The family "Bibionidae" or St Mark's Flies as they are commonly known contains 18 species - Bibio (14) and Dilophus (4). 14 species have been recorded in Wales of which 8 are in Glamorgan according to the NBN Gateway. The species below is Bibio pomonae who's English name is - The Heather Fly and seems to be quite common in the upper valley, where Heather grows although this one was feeding on Hogweed. I also recorded them feeding on Ragwort and the Butterfly Bush. The males have large eyes like this one, while the females eyes are very small, making them look like a different species. Bibio have spurs on the tibia where it joins the tarsi, while Dilophus does not. The leg pattern on this species is diagnostic for the males.