St Mark’s Fly

Bibio marci


Over all length 12 - 14mm. Black-bodied, hairy fly that flies clumsily with legs dangling, the males often in a small cloud above a hedgerow . The male has a dark leading edge to the wing while the females wings are tinted dark.


Hedgerows and grasslands where there are damp areas for the larvae to develop in.

Status and distribution

A very common and well distributed species. Regular at the reserve in good numbers.

Best time to see

Late April to early June.