Milder Weather Fuels Screwworm Resurgence in the US
Milder Weather Fuels Screwworm Resurgence in the US
US · Published Nov 12, 2026
• The New World screwworm, a deadly livestock parasite, has seen a resurgence in the US due to milder temperatures and increased humidity.
• Over 40 cases have been confirmed in November, marking the worst month since the pest first appeared in Texas earlier this year.

Impact & Risks

The screwworm outbreak poses significant risks to livestock, particularly in Texas, Arizona, and New Mexico. The parasite's spread is facilitated by animal movement, raising concerns about cattle imports from Mexico, where active cases exceed 1,500. Ranchers fear economic losses due to infected livestock and potential disruptions in trade. The USDA's containment efforts are challenged by favourable weather conditions for the parasite's reproduction, increasing the risk of further spread.

Related News