Yellow Swarming Fly vs Trimmer's Mining Bee

Side-by-side species comparison

Attribute Yellow Swarming Fly Trimmer's Mining Bee
Scientific Name Thaumatomyia notata Andrena trimmerana
Order Diptera Hymenoptera
Family Chloropidae Andrenidae
Size 2-2.5 mm 10-12 mm
Habitat Grasslands Grasslands
Diet Predators Nectar Feeders
Regions Europe Europe
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.

Trimmer's Mining Bee

A widespread spring mining bee with brownish-grey fur and a distinctive tooth on the hind femur. It forages on a wide range of early-blooming flowers.

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Did You Know?

The small femoral tooth on its hind leg distinguishes it from nearly all other European Andrena species.