Sheep Nose Bot Fly vs South American Robber Fly

Side-by-side species comparison

Attribute Sheep Nose Bot Fly South American Robber Fly
Scientific Name Oestrus ovis Microstylum magnum
Order Diptera Diptera
Family Oestridae Asilidae
Size 10-12 mm 30-40 mm
Habitat Farmland Grasslands
Diet Parasites Predators
Regions Worldwide South America, Central America
Conservation Least Concern Least Concern

Sheep Nose Bot Fly

A parasitic fly that shoots live larvae into the nostrils of sheep and goats while in flight. Larvae develop inside the nasal sinuses, causing distress to livestock.

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Did You Know?

This fly does not lay eggs — it shoots live first-instar larvae directly into the nostrils of sheep while flying past at speed, a method called larviposition.

South American Robber Fly

A large, elongate robber fly from tropical regions with a slender abdomen and long spiny legs. It hunts from exposed perches and can catch large prey relative to its body size.

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Did You Know?

Some tropical Asilidae species are among the largest predatory flies in the world, rivaling small dragonflies in wingspan.