Glacier Black Fly vs Ozark Stiletto Fly

Side-by-side species comparison

Attribute Glacier Black Fly Ozark Stiletto Fly
Scientific Name Prosimulium alpestre Thereva frontalis
Order Diptera Diptera
Family Simuliidae Therevidae
Size 2-4 mm body length 8-11 mm
Habitat Mountains Woodlands
Diet Blood Feeders Predators
Regions Alps, Northern Europe North America
Conservation Least Concern Least Concern

Glacier Black Fly

A small black fly whose larvae develop in fast-flowing alpine streams. Adults are among the earliest insects active after snowmelt.

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Did You Know?

Larvae anchor themselves to rocks in torrential currents using silk pads and tiny hooks.

Ozark Stiletto Fly

A medium-sized stiletto fly with a grayish body covered in fine pale hairs and clear wings. It is commonly found resting on sunlit surfaces in open woodlands.

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Did You Know?

The larvae have a unique ability to move rapidly through loose sand using undulating body movements.