AUSTIN (Nexstar) The New World screwworm (NWS) a maggot which feeds off living flesh is on Texas’s doorstep.
Mexican authorities, as reported by the U.S. Department of Agriculture (USDA), have identified a pest in Sabinas Hidalgo, located in Nuevo León, Mexico. This city is less than a two-hour drive from Laredo, Texas.
“This is now the northernmost detection of NWS during this outbreak, and the one most threatening to the American cattle and livestock industry,” USDA stated on Sunday.
The USDA noted that a screwworm outbreak in Central America began in 2023, raising concerns about its potential spread as early as January. The parasite last severely affected the United States in the 1950s, causing farmers annual losses estimated at $50-$100 million in the Southwest. Although eradicated from the U.S. in 1966, Mexico faced recurrent outbreaks, costing Texas’s economy $283-$375 million annually until collaborative efforts successfully eliminated it from Mexico.
In June, Texas initiated a response team to address the NWS threat. Following this, U.S. Secretary of Agriculture Brooke Rollins announced plans for a new sterile fly production facility in Edinburg. This initiative, part of a five-prong strategy, aims to produce 300 million sterile flies weekly to control the population. The technique, developed by University of Texas entomologists Edward F. Knipling and Raymond C. Bushland, focuses on introducing sterile male flies to reduce pest numbers.
The USDA and the Texas Animal Health Commission (TAHC) support using the sterile fly technique as a reliable eradication method. However, Texas Agriculture Commissioner Sid Miller claims a new fly bait, combined with the sterile fly approach, can eliminate the pest in 90 days—a process that previously took decades to complete beyond the U.S. border.
Miller has introduced TDA Swormlure, a bait currently tested in Panama, a screwworm hotspot. Despite his confidence in its effectiveness, he mentioned challenges in gaining the USDA or TAHC’s approval for implementing the bait.
“They are still hell-bent on a 70-year-old technology of sterile flies only. There is a fly bait that kills 90% of these flies. All I’m asking is just put out the fly bait and stop this nonsense,” Miller said.
He believes the sterile fly technique will take too long to remove the pest, which could wreak havoc on the cattle industry in Texas, harming jobs and America’s food supply. He claims it will take four years to build the sterile fly production facility in south Texas. There is no specific timeline of when that facility will be operational.
“We don’t have four years to wait on sterile flies to solve this problem,” Miller said.
Nexstar reached out to the USDA to ask if it is considering TDA Swormlure and if it had a timeline for the new production facility, and are waiting for a response. Part of USDA’s five-prong approach to the NWS is investing $100 million on new technologies and new tools to combat the pest. The TDA Swormlure could be considered for that funding.
What to look out for
Signs of an animal infested with the New World screwworm include:
- Foul-smelling wounds with maggots
- Animals biting or licking their wounds
- Lesions in bellybuttons, ears and where branding has occured
- Lethargy
If an infestation is suspected, Texas A&M Agrilife recommends you contact authorities, like the Texas Animal Health Commission and Texas Parks and Wildlife, and notify your veterinarian.
You should then inspect the animal for signs of infestation and collect any samples to give to authorities. There are several treatment options, including topical treatments.
