March Fly vs Sweat Fly

Side-by-side species comparison

Attribute March Fly Sweat Fly
Scientific Name Bibio marci Hydrotaea irritans
Order Diptera Diptera
Family Bibionidae Muscidae
Size 10-13 mm 5-7 mm
Habitat Underground Farmland
Diet Detritivores Dung Feeders
Regions Europe Europe, North America
Conservation Least Concern Least Concern

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.

Sweat Fly

A small dark fly attracted to perspiration on humans and livestock. It forms dense head-circling swarms in summer that can be extremely annoying.

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Did You Know?

Swarms of these flies can reduce cattle weight gain by causing constant head-tossing behavior.