A New World screwworm fly detected within 25 miles of the Texas-Mexico border has prompted a multi-front USDA and Texas response, including closing livestock ports and building a $750 million sterile fly facility at Moore Air Base. Officials say the U.S. risk
The alarm didn’t come from a verified case inside the United States. It came from a fly—small, parasitic, and capable of turning a wound into a crisis—showing up closer to the Texas-Mexico line than it ever has.
On Tuesday. June 2. USDA Secretary Brooke Rollins told reporters that the New World screwworm has been detected in Coahuila. Mexico. marking its closest approach to American soil to date: 25 miles from the U.S.-Mexico border. As of June 2. no cases have been reported in the U.S.—but officials are moving as if the next step could be closer still.
Rollins said her department is actively working to prevent the New World screwworm from entering the U.S. and, if it does, to combat it. She framed the effort as an answer to what farmers and ranchers endured the last time screwworm control failed at a wide scale.
“The New World screwworm crisis farmers and ranchers experienced back then will not repeat itself today,” Rollins said. “Unlike then, USDA is leading a robust, detailed and technologically advanced response.”
That response is already shaping everyday logistics. Officials said the federal government is closing U.S.-Mexico livestock ports as part of a broader plan that also includes construction of a new $750 million sterile fly production facility at Moore Air Base in South Texas.
One of the sharpest moments in the briefing came from how officials described the distance between what people feared and what was actually confirmed. Rollins stressed that the latest detections in Mexico are not the same thing as an infestation in the U.S.—and she pushed back against misleading headlines that had circulated about a detection “one mile from the Texas border.”.
Those claims were tied to a June 1 social media post by Texas state Rep. Don McLaughlin, R-Uvalde.
“When that false information gets out. it causes significant panic. and rightly so. and especially if it’s coming from elected officials and from media. ” Rollins said. “In an effort to get information out to be as transparent as possible. to make sure that everyone who’s tracking this and who wants to track it has access to every single thing that we know.”.
The USDA’s message was direct: as Mexico’s fly population presses north, the U.S. isn’t waiting for proof inside its borders to act.
The New World screwworm is a parasitic fly that impacts livestock. pets. wildlife. and. less commonly. people and birds. according to the USDA. Their larvae feed on the living tissue of warm-blooded animals. The current risk to animals and people in the United States remains very low. officials said. and the USDA says NWS is not contagious.
Screwworm infestations begin when a female fly lays eggs on a wound or body opening. The eggs hatch into larvae that burrow into the wound and feed on living tissue. After about 7 days of feeding, the larvae drop to the ground, burrow into the soil, and pupate. The adult screwworm fly emerges from the soil after 7 to 54 days.
Officials said the scientific timeline matters because it turns prevention into a time-sensitive mission: if the fly gets close enough to find wounds, the next phase can begin before an outbreak is obvious.
Rollins said cases have been reported in Mexico. including a recent detection 25 miles from the U.S.-Mexico border in Coahuila. She said last week Mexico reported up to eight New World screwworm detections. One of those was detected 25 miles from the border with the goat in Coahuila. described by Rollins as the closest detection to date.
Rollins also said the development hadn’t caught USDA off guard. She said she implemented a five-pronged plan last summer to detect, control and combat the NWS.
As the threat has advanced closer to Texas, officials said the activity is being reported closer to the Texas portion of the U.S. Southern border than in New Mexico, Arizona and California.
The U.S. investment plan includes closing U.S.-Mexico livestock ports and building new sterile fly capacity at Moore Air Base in South Texas. USDA said that facility will be capable of producing up to 300 million additional sterile flies per week. Rollins said those sterile flies are intended to be released in certain areas to stop NWS from reproducing and to help push the problem back to South America.
The Texas investment sits on top of another step in Mexico: officials said there is also an additional $21 million investment to convert an existing facility in Metapa, Mexico, into an NWS sterile fly dispersal facility.
On the Texas side. the Texas Animal Health Commission is watching closely and trying to get the response out to rural communities before any confusion becomes costly. Director Dr. Bud Dinges said TAHC staff are constantly monitoring traps for NWS detection and working with USDA to leverage and expand existing ground release sites for the distribution of sterile flies in South Texas.
Dinges said TAHC staff are also increasing their presence in South Texas to bolster outreach programs—aimed at giving locals awareness and resources.
He urged Texans to keep a close eye on their animals, particularly for open wounds and infestations.
Dinges delivered one of the most specific numbers from the briefing: “Over 58,000 suspicious flies have been submitted for official identification, and none have been detected by New World as New World screwworms,” he said. Still, he cautioned that the risk is not something Texas can assume away.
“It remains possible that New World screwworms will never reach Texas. However, given the expanding New World screwworms and fly population in Mexico and the severe threat it poses to Texas livestock industry, livestock and wildlife industries, we now must prepare and act as if it will.”
At the center of the effort is a practical question—what to do if someone suspects an infestation. Officials said if individuals suspect an animal may be infested with New World screwworms, they should notify the Texas Animal Health Commission or a local veterinarian immediately.
USDA has also set up a way for the public to ask questions: an email address, screwworm@usda.gov, where people can submit inquiries about NWS. Officials also urged the public to visit screwworm.gov for more information and the latest updates on New World screwworms.
The immediate facts remain reassuring on paper—no reported U.S. cases as of June 2, very low risk, and the USDA’s position that NWS is not contagious. But the proximity—25 miles into Mexico’s Coahuila—has shifted the tone from monitoring to readiness. with Texas livestock and wildlife now facing the kind of warning that arrives before the first outbreak is even confirmed.
New World screwworm USDA Brooke Rollins Texas Animal Health Commission Moore Air Base sterile fly facility livestock ports Coahuila screwworm@usda.gov