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

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Example Sentences

See Examples For:

screwworm

New World screwworm differs sharply from most fly larvae.

From Science Daily ● Sep. 15, 2026

The Agriculture Department said last month that it would reopen ports along the southern border to Mexican cattle that had been shut out because of concerns about spreading a flesh-eating parasite called New World screwworm.

From The Wall Street Journal ● Aug. 21, 2026

These include threats to animal health, including the New World screwworm, a flesh-eating parasite.

From Barron's ● Aug. 21, 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

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 Harold Bell Wright

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