American Horse Fly vs Robber Fly

Side-by-side species comparison

Attribute American Horse Fly Robber Fly
Scientific Name Tabanus americanus Promachus rufipes
Order Diptera Diptera
Family Tabanidae Asilidae
Size 20-28 mm 15-30 mm
Habitat Ponds & Lakes Meadows
Diet Blood Feeders Predators
Regions Eastern and central United States North America, Europe
Conservation Least Concern Least Concern

American Horse Fly

One of the largest horse flies in North America with a dark brown body and conspicuous green or purple iridescent eyes. Females deliver a painful slashing bite to obtain blood meals.

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Did You Know?

Its knife-like mouthparts slice open skin rather than piercing it, which is why horse fly bites bleed so freely.

Robber Fly

Aggressive aerial predators that catch other insects in flight. Inject prey with neurotoxic saliva that paralyzes and liquefies internal organs for consumption.

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Did You Know?

Robber flies are such efficient aerial predators that they have been recorded catching dragonflies, wasps, and even other robber flies in mid-air.