New World Screwworm detected in US wildlife as eradication efforts face new challenges

The parasitic fly has infested wildlife across Central America and reached livestock in 34 US animals, with officials struggling to contain its northward spread.

• US officials have detected screwworm in 34 animals across Texas and New Mexico, all in livestock and pets, with no wildlife detections in the US so far.
• The US is dropping 100 million sterile flies in the south-west and Mexico, but experts say 500 million would be needed to push the population back south.
• A sterile fly facility opened in Mexico in late June, with another in Texas planned for late 2027, as officials rush to expand breeding capacity.
• The Wildlife Conservation Society reported that cameras in Central American forests captured wildlife including jaguar, puma, and deer infected with screwworm, indicating the fly has become endemic in remote forest interiors.