By Jamie Martin
Screwworm flies are making their way north through Mexico, now within 400 miles of the Texas border. These parasitic pests lay larvae in wounds of animals like cattle and sheep, causing severe infections and economic loss.
Eradicated in the U.S. since the 1970s, screwworms were once controlled by releasing sterile male flies—an innovation by the USDA. However, since 2023, the flies have been moving north again, sparking urgent responses.
To prevent an outbreak, the USDA suspended Mexican cattle imports and plans to build a sterile fly dispersal center in Edinburg, Texas. Senator John Cornyn is pushing for additional funding to build a new $300 million fly production plant, though it may take years to complete.
Meanwhile, $21 million is being invested to convert a southern Mexico fruit fly facility to produce more sterile screwworms. These efforts aim to increase supply and strengthen defenses at the U.S.-Mexico border.
If the flies reach Texas, livestock owners face the return of labor-intensive monitoring and care. Rancher John Kearney recalls checking every cow daily during past outbreaks, a routine that could soon return.
The Texas Department of Agriculture, along with agencies like the Animal Health Commission and Texas Parks and Wildlife, have formed a coalition to monitor the threat. They plan to use Swormlure-5 bait traps near the border and have launched screwwormtx.org for updates.
Industries such as whitetail deer breeding also face risks. With collaborative efforts and early interventions, leaders hope to prevent a widespread screwworm resurgence in Texas.
Photo Credit: gettyimages-oticki
Categories: National