screwworm

noun

screw·​worm ˈskrü-ˌwərm 

1

: a blowfly (Cochliomyia hominivorax) of the warmer parts of America whose larva develops in sores or wounds or in the nostrils of mammals including humans with serious or sometimes fatal results

especially : its larva

2

: any of several flies other than the screwworm and especially their larvae which parasitize the flesh of mammals

Examples of screwworm in a Sentence

Recent Examples on the Web

Cows are the screwworm’s favorite feast, but the maggots can also feed on other livestock as well as wildlife and pets. —Geraldine Castro, WIRED, 4 Dec. 2024

Livestock showing New World screwworm symptoms should be reported to the Texas Animal Health Commission or the U.S. Department of Agriculture. —Tommy Tuberville, Newsweek, 9 Jan. 2025

Such an infestation is known as New World screwworm myiasis. —Li Cohen, CBS News, 6 Jan. 2025

His analysis detected patterns of the screwworm advancing up to 300 kilometers between outbreaks. —Geraldine Castro, WIRED, 4 Dec. 2024

Though they are most commonly associated with animals, screwworm infections can have serious consequences for the health of humans. —Yaakov Katz, Newsweek, 28 Nov. 2024

Screwworm infections are caused by parasitic larvae of fly species, most significantly the New World screwworm fly. —Yaakov Katz, Newsweek, 28 Nov. 2024

The United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) announced that a New World screwworm (NWS) was detected in Mexico on Friday, causing the agency to pause animal imports from the country. —Ashleigh Fields, The Hill, 26 Nov. 2024

Sterilized male screwworms are released to mate with females, which lay eggs that don’t hatch. —Emily Mullin, WIRED, 28 June 2023

Word History

First Known Use

1846, in the meaning defined at sense 1

Kids Definition

screwworm

noun

screw·​worm ˈskrü-ˌwərm 

: the larva of a blowfly of the warm parts of America that develops in the wounds or sores of mammals and may cause disease or death

also : the blowfly itself

Medical Definition

screwworm

noun

screw·​worm ˈskrü-ˌwərm 

1

: either of two dipteran flies of the genus Cochliomyia:

a

: one (C. hominivorax) of the warmer parts of America whose larva develops in sores or wounds or in the nostrils of mammals including humans with serious or sometimes fatal results

especially : its larva

b

: secondary screwworm

2

: a dipteran fly of the genus Chrysomya (C. bezziana) that causes myiasis in Africa and southern Asia