Black-Tailed Deer Fly vs Northern Black Fly

Side-by-side species comparison

Attribute Black-Tailed Deer Fly Northern Black Fly
Scientific Name Chrysops niger Simulium venustum
Order Diptera Diptera
Family Tabanidae Simuliidae
Size 7-10 mm 2-4 mm
Habitat Wetlands Forests
Diet Blood Feeders Omnivores
Regions Northeastern United States and southeastern Canada North America
Conservation Least Concern Least Concern

Black-Tailed Deer Fly

A small dark deer fly with mostly blackened wings and green iridescent eyes. It is an aggressive daytime biter commonly encountered near wooded wetlands.

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Did You Know?

It is most active during overcast humid days and tends to bite repeatedly if swatted away without being killed.

Northern Black Fly

A common biting black fly of northern forests and boreal streams. Larvae form dense colonies on submerged rocks in cold flowing water.

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Did You Know?

Females can detect carbon dioxide exhaled by hosts from over 20 meters away.