Western Encephalitis Mosquito vs Aquatic Snail-killing Fly

Side-by-side species comparison

Attribute Western Encephalitis Mosquito Aquatic Snail-killing Fly
Scientific Name Culex tarsalis Sepedon sphegea
Order Diptera Diptera
Family Culicidae Sciomyzidae
Size 4-6 mm 5-9 mm
Habitat Wetlands Wetlands
Diet Blood Feeders Predators
Regions Western North America, from Canada to Mexico North America
Conservation Least Concern Least Concern

Western Encephalitis Mosquito

A medium-sized mosquito with a distinctive white band on the proboscis and banded legs. It is the most important vector of Western equine encephalitis and St. Louis encephalitis in western North America. It breeds in a wide variety of sunlit and shaded water sources.

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Did You Know?

Its feeding behavior shifts seasonally from birds in spring to mammals in late summer, which drives encephalitis virus spillover to humans.

Aquatic Snail-killing Fly

A slender marsh fly with a distinctly pointed abdomen and yellowish-brown coloring. Larvae are aquatic predators of freshwater snails, attacking them underwater.

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Did You Know?

A single larva may consume multiple snails during its development, making it an effective natural snail control agent.