American Horse Fly vs Caterpillar Tachinid

Side-by-side species comparison

Attribute American Horse Fly Caterpillar Tachinid
Scientific Name Tabanus americanus Lydella thompsoni
Order Diptera Diptera
Family Tabanidae Tachinidae
Size 20-28 mm 5-8 mm
Habitat Ponds & Lakes Farmland
Diet Blood Feeders Parasites
Regions Eastern and central United States Europe, North America
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.

Caterpillar Tachinid

A small gray parasitic fly that attacks European corn borer larvae. It was introduced to North America as a biological control agent.

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Did You Know?

Females deposit live larvae rather than eggs directly onto the host caterpillar.