Fly Shortage Left United States Exposed To Flesh-Eating Screwworm

Fly shortages exposed the US to flesh-eating screwworms, prompting cattle border closures and calls for hunter assistance.

Shortages of factory-bred sterile flies left the United States vulnerable to an outbreak of the flesh-eating New World screwworm. Authorities previously relied on releasing billions of sterile insects to control the parasite, but dwindling supplies forced border closures for cattle imports. Officials and researchers now look to millions of hunters to help detect and contain the spreading pest.

• The causeA severe shortage of factory-bred sterile flies compromised decades-long containment efforts against the parasite.
• The actionAuthorities suspended cattle imports from Mexico for over 15 months starting in May 2025.
• Who is affectedResearchers note that hunters numbering 11.5 million across America can act as frontline observers to spot cases.

What's new · 18h agoReports detailed that a shortage of sterile flies led the administration of US President Donald Trump to shut the Mexican border to cattle imports for over 15 months beginning in May 2025.