Walnut Husk Fly vs Window Fly

Side-by-side species comparison

Attribute Walnut Husk Fly Window Fly
Scientific Name Rhagoletis completa Scenopinus fenestralis
Order Diptera Diptera
Family Tephritidae Scenopinidae
Size 5-7 mm 5-7 mm
Habitat Orchards Indoors
Diet Fruit Feeders Predators
Regions North America, Southern Europe Worldwide
Conservation Least Concern Least Concern

Walnut Husk Fly

A fruit fly whose larvae feed inside walnut husks, staining and damaging the nuts. It has become an invasive pest in European walnut-growing regions.

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Did You Know?

Larval feeding stains walnut shells black, making them unmarketable even though the nut inside may be fine.

Window Fly

A small shiny black fly often found on windowsills inside buildings. Its larvae are beneficial predators of carpet beetle and clothes moth larvae.

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Did You Know?

Despite being found indoors, it is actually beneficial because its larvae eat destructive carpet beetles.