screwworm

American  

[skroo-wurm] / ˈskruˌwɜrm /

noun

1. the larva of any of certain flies of the genus Callitroga, which sometimes infests wounds and the nose and navel of domestic animals and humans.

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screwworm British  

/ ˈskruːˌwɜːm /

noun

1. the larva of a dipterous fly, Callitroga macellaria, that develops beneath the skin of living mammals often causing illness or death

2. the fly producing this larva: family Calliphoridae

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Etymology

Origin of screwworm

An Americanism dating back to 1875–80; screw + worm

Example Sentences

See Examples For:

screwworm

U.S. imports of Mexican cattle have been suspended since May 11, 2025 because of the rapid spread of screwworm in Mexico at the time.

From MarketWatch ● Jul. 28, 2026

Agriculture Department will allow cattle imports from Mexico for the first time in more than a year beginning in late August, even as New World screwworm remains a threat to domestic livestock.

From MarketWatch ● Jul. 28, 2026

Ranchers and vets say this $4 treatment for cattle will help them beat back flesh-eating screwworm.

From MarketWatch ● Jun. 12, 2026

The New World screwworm is a fly that lays hundreds of eggs in the open wounds or body orifices of warm-blooded animals, even openings as small as a tick bite.

From The Wall Street Journal ● Jun. 12, 2026

As Phil explained to Patches while they watered their horses, the screwworm is the larva of a blowfly bred in sores on living animals.

From When A Man's A Man by Wright, Harold Bell