St Mark's Fly - Bibio marci
The male is about 12 mm and the female 14 mm. This is quite a hairy black insect. The males have large bulbous eyes and a rather tubular segmented body and black legs. The females have smoky wings and much a smaller head and eyes. The front legs have a stout spine at the tip of the tibia.
Other Bibio species are broadly similar, though B. marci is larger than most.
Hedgerows and woodland edge, often in moist areas.
Named after St. Marks day, 25th April, when they appear with amazing regularity. April - June.
When airborne, they fly in a sluggish manner above hedgerows and grass, with their long legs dangling down. The larvae feed on grass roots, leaf mould and decaying matter.
Common and widespread in Britain.
Common in Leicestershire and Rutland
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Species profile
- Common names
- St Marks Fly
- Species group:
- Craneflies, Gnats & Midges
- Kingdom:
- Animalia
- Order:
- Diptera
- Family:
- Bibionidae
- Records on NatureSpot:
- 132
- First record:
- 22/04/2009 (Calow, Graham)
- Last record:
- 06/05/2024 (Hunt, Graham)
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% of records within its species group
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