St Marks Fly Bibio marci

Species Information
Length male 12 mm, female 14 mm. Also called the Hawthorn Fly, it is a very black and hairy fly, and slow moving in flight. The males have large bulbous eyes, where as the females are smaller, and the wings are darker.

The larva feeds on the roots of grasses, dead matter and leaf mould. The adult flies April to June, and it appears around 25th April, St Mark’s Day. Found in Hedgerows and on woodland edges, and along riverbanks. Common and widespread in Britain.

Classification

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Insecta (Insects)
Diptera (True Flies)
Nematocera (Lower Diptera)
Bibionomorpha
Bibionoidea
Bibionidae (St Marks Flies)
Bibio
Bibio marci (Linnaeus, 1758)

Photographs

St Mark's Fly Bibio marci male
May 2020. Male, local woodland margin
St Mark's Fly Bibio marci female
May 2020. Female, local woodland margin

All photographs copyright © Peter Hillman
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