Louse Fly vs Stalk-Eyed Fly

Side-by-side species comparison

Attribute Louse Fly Stalk-Eyed Fly
Scientific Name Hippobosca equina Teleopsis dalmanni
Order Diptera Diptera
Family Hippoboscidae Diopsidae
Size 7-8 mm 6-10 mm body (eye span up to 25 mm)
Habitat Farmland Rivers & Streams
Diet Blood Feeders Fungus Feeders
Regions Europe, Asia, Africa Asia
Conservation Least Concern Least Concern

Louse Fly

A flattened bloodsucking fly parasite of horses and cattle with powerful clawed legs for clinging to fur. Adults are incredibly tough and difficult to crush.

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Did You Know?

Its body is so tough and flattened that it can withstand being stepped on by its horse host without injury.

Stalk-Eyed Fly

Males have eyes on the tips of long rigid stalks that can span wider than their body length. Females prefer males with wider eye spans, driving extreme sexual selection.

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Did You Know?

Males compete by facing each other and comparing eye span — the wider-eyed male wins. Females prefer wide-eyed males because eye span indicates good genes.