Small-headed Fly vs March Fly

Side-by-side species comparison

Attribute Small-headed Fly March Fly
Scientific Name Ogcodes pallidipennis Bibio marci
Order Diptera Diptera
Family Acroceridae Bibionidae
Size 4-8 mm 10-13 mm
Habitat Grasslands Underground
Diet Parasitoids Detritivores
Regions Europe Europe
Conservation Least Concern Least Concern

Small-headed Fly

A round-bodied fly with a tiny head whose larva parasitizes spiders from the inside.

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Did You Know?

The first-instar larva attaches to a passing spider and burrows inside to feed.

March Fly

A common black fly that swarms in large numbers around Saint Marks Day in April.

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Did You Know?

Mating pairs fly joined together with the smaller male dangling beneath the female.