To fight screwworm, the U.S. is opening a South Texas facility to disperse sterile flies

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McALLEN — The U.S. Department of Agriculture is ramping up efforts to fight the spread of New World screwworm across the southern border by opening a sterile fly dispersal facility in South Texas.

Agriculture Secretary Brooke Rollins announced a plan to combat the threat of the parasitic insect that includes investing $8.5 million to build a sterile fly dispersal facility at Moore Air Base in Edinburg. It is expected to open in six months.

The screwworm is a parasitic fly that targets warm-blooded animals and has the potential to disrupt Texas’ $15 billion cattle industry.

The facility will help distribute the organisms used to combat the screwworm: sterile flies. Sterile male screwworm flies mate with fertile female screwworms that produce non-viable eggs until the population dies out.

Panama is home to the only facility in the world that produces sterile screwworm flies, producing about 117 million flies per week. Another facility in Mexico will be renovated to produce an additional 60-100 million sterile flies per week, a $21 million investment from the USDA. The larvae produced at those sites will be flown to Edinburg in the Rio Grande Valley, where they will finish growing. When they're ready, they will be distributed to areas in Mexico to combat the screwworm.

“We have defeated the screwworm before and we will do it again,” Rollins said during a news conference in Edinburg on Wednesday. “We want to keep this production going as we apply full force to stopping the screwworm from spreading north and getting closer to our border.”

Screwworm has already spread through Central America, with recent detections as far north as Oaxaca and Veracruz, Mexico, 700 miles away from the Texas-Mexico border.

To mitigate the spread into the U.S., the USDA temporarily closed the southern border to imports of live cattle, horses and bison in May. This has limited the supply of cattle, driving up their cost.

Screwworm was largely eradicated in the U.S. in the 1960s with the use of sterile flies to kill off the screwworm fly population. At that time, Moore Air Base served as a fly dispersal facility and will be revived as such under the USDA plan.

Rollins added the department is exploring opening a sterile fly production facility at the air base to complement the dispersal facility and provide an additional 300 million sterile flies per week. However, the construction of this new production facility would take two to three years.

Federal lawmakers have pushed for a new sterile fly rearing and dispersal facility.

U.S. Sens. John Cornyn and Ted Cruz of Texas and Sen. Ben Ray Luján of New Mexico introduced legislation to fund such a facility, and U.S. Rep. Tony Gonzales of San Antonio is leading a similar bill in the House.

U.S. Rep. Monica De La Cruz, R-Edinburg, introduced a bill directing the USDA to conduct a study and report strategies to enhance preparedness and response capabilities against potential outbreaks of the New World Screwworm.

As part of their current plan, USDA is partnering with Texas animal health officials to finalize emergency management plans and stockpile therapeutics. They are also investing in research to develop new treatments, preventive methods and new response strategies.

The Texas Department of Agriculture is also working with the USDA to inspect trucks entering the state for disease, pestilence and insects.

Sid Miller, the Texas agriculture commissioner, said the state is working on obtaining a permit to inject cattle feed with parasiticide. He also said the department set aside $250,000 for fly traps that will be set along the Rio Grande that can alert officials of the spread of screwworm into Texas before infections occur in the state.

Miller added he spoke with Lt. Gov. Dan Patrick, who serves as the president of the Texas Senate, and Texas Speaker of the House Dustin Burrows to add screwworm to their list of priorities for the next legislative session.

“We’re kind of the tip of the spear when it comes to the screwworm,” Miller said. “We want to be ready should this insect infect Texas.”

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

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