U.S. will build sterile fly factory in Texas to stop screwworm from devastating livestock industry

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McALLEN — The federal government is ramping up efforts in Texas to combat the spread of New World Screwworm, a pest that could devastate the cattle and wildlife industries in Texas and the nation.

The U.S. Department of Agriculture announced a slew of new initiatives and investments to monitor and prevent the spread of screwworm, which is traveling north through Mexico and was detected about 370 miles south of the U.S./Mexico border in July.

Screwworms are parasitic flies that lay larvae in open wounds of live, warm-blooded animals, causing them serious harm and, potentially, death.

Among the investments is a $750 million facility in Edinburg that will produce about 300 million sterile screwworm flies per week, Agriculture Secretary Brooke Rollins announced during a news conference with Texas Gov. Greg Abbott on Friday.

By mating with sterile female flies, the intent is to produce non-viable eggs so that the population will eventually die out.

Rollins called the threat a national security issue that should concern all Americans.

The fly “endangers our livestock industry and it threatens the stability of beef prices for consumers across America," Rollins said.

The new production facility will be the first in the U.S. and will lessen U.S. dependency on production facilities in Panama and Mexico. It will also accompany an $8.5 million screwworm dispersal facility currently under construction at Moore Air Base in Edinburg. That facility will take larvae produced in Panama or Mexico, continue growing them, and distribute the hatched sterile flies to sites of infestation.

Construction of the production facility announced today is expected to take at least a year. Until it gets up and running, the USDA will spend up to $100 million on technology to accelerate the U.S. response, such as novel traps and modular sterile fly units.

Russell Boening, president of the Texas Farm Bureau, praised Rollins and the Trump administration on the new production facility.

“This threat is real and urgent, and we cannot afford delays,” Boening said in a statement. “Immediate construction and deployment of this facility are essential to prevent irreversible harm to the agricultural economy and our nation’s food system.”

USDA is also ramping up the hiring of mounted patrol officers, known as tick riders, who typically patrol the southern border to protect cattle from fever tick, but will also now serve as the first line of defense against screwworm by monitoring livestock apprehended along the border for screwworm.

The department's Beagle Bridge will be trained to detect screwworm infections and the USDA will work with their Mexican counterparts on surveillance training to track screwworm as it moves through the country in real time.

Texas last dealt with a screwworm infestation in the 1960s. In 2023, screwworm began to spread north of the Panama Canal. It was detected in Mexico last year, prompting the USDA to suspend imports of livestock from Mexico temporarily.

If it were to spread into the U.S., screwworm could cause an estimated $2.1 billion loss to cattle and a $9 billion loss to the hunting/wildlife industries in Texas.

In June, Abbott ordered the Texas Animal Health Commission and the Texas Parks and Wildlife Department to establish a Texas New World Screwworm Response Team to help coordinate and share information on efforts to stop the spread of screwworm.

"The reality is this is a national and international issue," Abbott said. "Our industries, our ranchers, people who buy groceries are going to face these dire consequences if action is not taken."

Reporting in the Rio Grande Valley is supported in part by the Methodist Healthcare Ministries of South Texas, Inc.

Disclosure: Texas Farm Bureau and Texas Parks And Wildlife Department have been financial supporters of The Texas Tribune, a nonprofit, nonpartisan news organization that is funded in part by donations from members, foundations and corporate sponsors. Financial supporters play no role in the Tribune's journalism. Find a complete list of them here.

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