USDA Expands New World Screwworm Surveillance as Cases Rise in Mexico and Sterile Fly Supply Stays Limited

USDA officials are increasing surveillance and sterile fly dispersal efforts as New World screwworm cases continue growing in Mexico near the Texas border.

WASHINGTON, D.C. (RFD NEWS) — The number of New World screwworm cases reported in Mexico continues to grow, prompting USDA officials to intensify surveillance and carefully manage the limited supply of sterile flies used to contain the pest’s spread.

USDA says sterile fly dispersal efforts are currently concentrated along the Gulf coast of northern Mexico, with additional drops occurring within roughly 50 miles of the Texas border.

Officials say the agency is relying heavily on predictive modeling and real-time surveillance data to determine where those flies are deployed.

“Right now we’re dropping flies mostly on the Gulf side, the northern Gulf side of Mexico. We have about 50 miles that these flies are also being dropped over the U.S. border in Texas. And so when we make these decisions, we look at a variety of different data based on modeling, and we predict, we forecast, and we assess based on a variety of different things, including the temperature, the humidity, the altitude, and all of these different aspects, as well as looking at data that we get from, number one, cases that Mexico shares with us, as well as, number two, data that we get from traps in the area as far as surveillance. All of those things come together and help us to determine where is the best use of our flies and how can we distribute what is a limited number that we have at this moment.”

USDA says those decisions are being made in coordination with the agency’s Agricultural Research Service, using predictive analytics designed to anticipate where the pest could spread next, not simply where cases are currently confirmed.

“Our modeling, and we do this in conjunction with the Agricultural Research Service at USDA, looks at predictive analytics to forecast and model where we think the fly is going to go next. And so we take into consideration things like temperature and altitude and humidity, but we also take into consideration all of those different things that are data sources for us. And so by and large, the majority of these data sources are provided to us by our partners in Mexico. What we do is we anticipate not where the fly is right now, but really where can the fly be moving towards. And so in an over-leaning of preparation, we lean forward aggressively as far as where we disperse our flies beyond where we know the flies to be, but where they could be in a few weeks.”Officials say preparations also extend beyond field operations. USDA and state partners continue conducting tabletop exercises and response planning scenarios designed to prepare for a wide range of possible outcomes should New World screwworm reach the United States.

USDA says those efforts are intended to ensure rapid response capabilities remain in place and that the country is prepared if the pest moves northward.

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Marion is a digital content manager for RFD News and FarmHER + RanchHER. She started working for Rural Media Group in May 2022, bringing a decade of digital experience in broadcast media and some cooking experience to the team.

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