St Mark's fly

I came across a swarm of insects on a visit to the Oak Tree Community farm to look for wildlife. I assumed the menacing dangling thing was either an ovipositor or possibly a sting. These were the same sort of thing that had been bugging me walking along north wall of Minsmere a week ago, but I didn't come away with any bites. They followed me around in  a small cloud along that stretch of the reserve.

 The appendages were neither sting nor ovipositor, simply long back legs, St Mark's flies otherwise known as Hawthorn flies are a little bit early this year for St Mark's Day 25th April.

St Mark's Fly Bibio marci

 

Mating - the larger female with smoky wings is above

Phil Gates has some fascinating detail of the large eyes on his cabinet of curiosities blog , which differ between males and females, the males have a visual system adapted to both hover and locate females, whereas the females have a simpler visual system without the fine hairs between the compound elements of the eyes in the male, which is just about visible as a fuzz in the lower male. The next pic taken a few days later shows one with stunningly hairy eyes

stunningly hairy eyes on this handsome specimen

 

St Mark's flies are harmless, indeed beneficial as they pollinate fruit trees and crops as the adults feed on nectar during their short lives.