Texas Forms Task Force for New World Screwworm

AUSTIN, TX — In response to the growing threat of New World screwworm reaching the state, the Texas Animal Health Commission and Texas Parks and Wildlife Department have formed a joint response team, officials announced Wednesday.

The screwworm is a parasitic fly that affects warm-blooded mammals, which includes humans in rare cases, though it's mostly viewed as a threat to livestock and wildlife.

The creation of the Texas New World Screwworm Response Team follows a directive from Governor Greg Abbott.

“Texas played a critical role in eradicating this pest from the United States in the 1960s and will do so again if the need arises,” Abbott said in his directive. “We stand ready to protect our land, livestock and wildlife.”

The new response team will coordinate preparedness and response activities, facilitate public education, and serve as a centralized resource for stakeholders statewide.

“Texans can be assured that staff have been actively preparing and training for a possible New World screwworm response for over a year,” said Dr. Lewis R. “Bud” Dinges, TAHC executive director and state veterinarian. “While we hope we don’t have to deal with the pest on our soil, joint efforts to mitigate damage and protect all commodities from NWS are ongoing and will be bolstered by this well-rounded team.”

The response comes amid growing concerns as NWS has spread northward through Central America and into Mexico. First detected in Panama in 2022, the pest reached southern Mexico by November 2024 and has continued spreading as far north as Oaxaca. Texas’s long border with Mexico and its extensive livestock and wildlife presence put the state at high risk for the potential reintroduction of the parasite.

“Excellent work has already been done by stakeholders, and state and federal agencies,” said Dr. David Yoskowitz, TPWD executive director. “The charge of the response team is to work directly with landowners, livestock producers and the public. Both the Texas Animal Health Commission and Texas Parks and Wildlife Department will bring forward all the resources and expertise at our disposal to ensure that we are prepared and can respond quickly and effectively.”

TAHC began formal NWS monitoring and staff training in March 2024, even before the pest reached Mexico. Since then, TAHC and TPWD have ramped up public education and interagency coordination, laying the groundwork for the newly established response team.

New World screwworm infestations begin when a female fly lays eggs on a wound or orifice of a live, warm-blooded animal. Wounds as small as a tick bite may attract a female fly to feed. 

Eggs hatch into larvae that burrow into the wound to feed on the living flesh. After about 7 days of feeding, larvae drop to the ground, burrow into the soil, and pupate. The adult screwworm fly emerges from the soil after 7 – 54 days, depending on temperature and humidity.