Chinese Windmill Butterfly vs Fever Fly

Side-by-side species comparison

Attribute	Chinese Windmill Butterfly	Fever Fly
Scientific Name	Byasa alcinous	Dilophus febrilis
Order	Lepidoptera	Diptera
Family	Papilionidae	Bibionidae
Size	Wingspan 75-95 mm	5-7 mm
Habitat	Forests	Farmland
Diet	Nectar Feeders	Nectar Feeders
Regions	China, Japan, Korea, Taiwan	Europe, Asia
Conservation	Least Concern	Least Concern

Chinese Windmill Butterfly

A dark swallowtail with red-spotted hindwings that rotates its wings in a slow windmill-like pattern during flight. It is widespread in East Asian lowland forests.

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Did You Know?

Its distinctive slow, spinning flight style gives it the common name windmill butterfly.

Fever Fly

A small, shiny black march fly with spiny front tibiae used for digging. It was once believed to cause fevers in humans, hence its common name, though it is completely harmless.

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Did You Know?

Its spiny front legs are used by females to dig into soil for egg-laying, an unusual adaptation among flies.