Federal and Texas officials marked the completion of a new sterile fly dispersal facility at Moore Air Base this week, strengthening U.S. defenses against the New World screwworm (NWS) as cases in Mexico remain within a few hundred miles of the border.
Leaders from the U.S. Department of Agriculture said the South Texas facility expands the agency’s ability to release sterile male flies along the border — and inside the United States if needed — to prevent the parasitic pest from spreading north.
While no screwworm detections have been confirmed within the U.S., the northernmost active case in Mexico is approximately 200 miles from the border. USDA continues surveillance and trapping efforts in response.
How sterile flies work
The sterile insect technique remains the cornerstone of screwworm control. Female flies mate only once in their lifetime. If they mate with a sterile male, the eggs they lay do not hatch, gradually reducing the population.
Sterile flies are primarily dispersed by aircraft to ensure even coverage across large areas, including terrain that is difficult to access from the ground.
Expanding response capacity
Sterile flies used in current border operations are being dispersed from a facility in Tampico, Mexico. The newly completed Texas site provides USDA with a domestic dispersal option should outbreak patterns shift.
Production capacity is also expanding. Sterile flies are currently produced at a facility in Panama. Renovations underway in Mexico are expected to increase supply later this year. USDA has also announced plans to construct a sterile fly production facility at Moore Air Base with a targeted capacity of 300 million flies per week.
When all facilities are operational, USDA projects total production capacity could reach up to 500 million sterile flies weekly.
What producers should watch for
New World screwworm larvae infest open wounds and feed on living tissue in livestock, wildlife, pets, and occasionally humans. Untreated cases can lead to severe tissue damage and death.
USDA is urging livestock owners to regularly inspect animals for draining or enlarging wounds, visible larvae, or signs of discomfort. Particular attention should be paid to newborn navels and natural body openings.
Any suspected case should be reported immediately to state animal health officials or a USDA veterinarian.
The U.S. successfully eradicated screwworm decades ago through sterile fly programs. Officials say the new Texas dispersal facility strengthens preparedness efforts aimed at keeping the pest from re-establishing north of the border.
