Florida Tightens Rules as NWS Nears

REDFIELD, Iowa (DTN) -- As New World screwworm (NWS) cases increase in northern Mexico, another Southern state -- Florida -- has begun instituting new restrictions and regulations to protect U.S. livestock.

Current NWS cases in Mexico total 21,293, with 1,469 being active animal cases, according to the USDA Animal and Plant Health Inspection Service (APHIS) website. These cases include several in the northern Mexican states of Nuevo Leon and Tamaulipas. Both states are in the sterile insect dispersal polygon. Parts of southern Texas have been the site of the release of NWS sterile flies since January 2026.

Tamaulipas currently has 246 cases, with 116 being active. In Nuevo Leon, there are 13 total cases, with eight being active. One of these cases is within 62 miles of the U.S. border, according to Texas Agriculture Commissioner Sid Miller.

"The threat of New World screwworm is creeping dangerously close to our border," Miller said. "A confirmed case in Nuevo Leon, just about 60 miles from the United States, in a young calf, is a flashing red warning sign we will not ignore."

A sterile fly facility is currently being constructed on the Moore Air Base in Edinburg, Texas. This facility will start producing 100 million sterile flies by the end of 2027 and ramp up to 300 million by the end of 2028. Currently, a facility in Panama is the only place producing sterile flies, and one in Metapa, Mexico, will come online this summer.

FLORIDA RESTRICTS REGIONAL TEXAS ANIMALS

Last week, in response to the NWS cases moving closer to the U.S., Florida Commissioner of Agriculture Wilton Simpson issued an emergency rule placing temporary restrictions on the importation of animals into Florida from high-risk Texas counties.

"We are taking aggressive action to further protect Florida and our agricultural producers from the real threat or the New World screwworm," said Simpson in a news release from last week. "We know how costly and dangerous this pest can be to our agricultural industry if it takes hold, and we will use every tool at our disposal to protect our state. We're also calling on Florida's producers, veterinarians, and animal health professionals to remain aware and act quickly if they suspect something unusual."

The emergency rule currently includes the temporary restriction of movement of all warm-blooded animals from the following southern Texas counties: Zapata, Jim Hogg, Starr, Hidalgo, Webb and Brooks, and requires animals from these areas to undergo increased veterinary screenings and treatment, if necessary.

Miller understands Florida's move to protect the state from NWS.

"With the growing threat of New World screwworm, and as ground zero of America's last outbreak a decade ago, they're acting to protect their state. This isn't a distant risk, and their heightened biosecurity makes that clear."

The requirements include that these animals be accompanied by an Official Certificate of Veterinary Inspection (OCVI) to document that all animals on the form that have been inspected are found free of contagious and infectious disease and pests, including NWS.

Any animals with wounds must not have an NWS larvae infestation, but if they do have a wound, they must be treated using an effective treatment to meet the Florida requirements. The wound location and treatment must be documented on the OCVI.

Anyone who suspects an NWS case in the U.S. should contact their veterinarian immediately, including reporting sick or injured wildlife.

"Our ranchers feed this country and fuel the Texas economy. They deserve vigilance, urgency, and action. We've beaten the New World screwworm before, and we will beat it again, but only if we treat this threat with the seriousness it demands right now," Miller said.

NWS is currently not found in the United States. The border between Mexico and the U.S. remains closed. For further information, visit https://www.aphis.usda.gov/….

Jennifer Carrico can be reached at jennifer.carrico@dtn.com

Follow her on social platform X @JennCattleGal

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