Yellow Swarming Fly vs Ant-decapitating Fly

Side-by-side species comparison

Attribute Yellow Swarming Fly Ant-decapitating Fly
Scientific Name Thaumatomyia notata Pseudacteon tricuspis
Order Diptera Diptera
Family Chloropidae Phoridae
Size 2-2.5 mm 1-2 mm
Habitat Grasslands Farmland
Diet Predators Parasitoids
Regions Europe South America, introduced to North America for biocontrol
Conservation Least Concern Least Concern

Yellow Swarming Fly

A tiny yellow fly famous for forming enormous hibernation aggregations in buildings, sometimes numbering millions. Larvae are predatory on root aphids in grassland.

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Did You Know?

Can form hibernation clusters of millions in attic spaces, with individual aggregations weighing several kilograms.

Ant-decapitating Fly

A minute parasitoid fly that targets fire ants by injecting eggs into their bodies. The developing larva migrates to the ant's head, eventually causing it to fall off.

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Did You Know?

The larva releases enzymes that dissolve the ant's head contents, and the head eventually falls off to serve as a pupation chamber.