Mexico has failed to โregularly maintain fly traps as agreed,โ thereby negatively affecting detection efforts, said Secretary Brooke Rollins.
More than 8,000 traps have been deployed across Texas, Arizona, and New Mexico, targeting the New World screwworm (NWS) flies, Secretary of Agriculture Brooke Rollins said in a Sept. 26 post on X, adding that no additional NWS infections have been detected since last Sunday.
๐จ ๐๐๐ ๐๐๐๐๐๐ ๐๐๐๐๐๐ – ๐ต๐ถ ๐จ๐ซ๐ซ๐ฐ๐ป๐ฐ๐ถ๐ต๐จ๐ณ ๐ต๐พ๐บ ๐ญ๐ณ๐ฐ๐ฌ๐บ ๐ซ๐ฌ๐ป๐ฌ๐ช๐ป๐ฌ๐ซ ๐บ๐ฐ๐ต๐ช๐ฌ ๐พ๐ถ๐ผ๐ต๐ซ ๐ซ๐ฌ๐ป๐ฌ๐ช๐ป๐ฌ๐ซ ๐ณ๐จ๐บ๐ป ๐บ๐ผ๐ต๐ซ๐จ๐.
— Secretary Brooke Rollins (@SecRollins) September 26, 2025
In addition to last 7 months of effort after inaction from previous administration:
โ 8,000+ traps deployed acrossโฆ
On Sunday, Sept. 21, an announcement was made by the U.S. Department of Agriculture (USDA), which said that Mexicoโs National Service of Agro-Alimentary Health, Safety, and Quality had confirmed a new NWS infection in Sabinas Hidalgo, Nueva Leon state, less than 70 miles from Americaโs southern border. The infected animal was an 8-month-old cow.
Earlier in July, an NWS infection had been reported 370 miles south of the U.S.โMexico border.
In her post, Rollins said that over 13,000 screening samples have been screened, and zero NWS flies have been identified thus far.
In addition, 750,000 sterilized NWS flies are being trucked in and dispersed in the Nueva Leon region twice a week, she said.
Mass-produced, sterile male NWS flies are often used to tackle the spread of wild NWS fly swarms. When these sterile flies are released into a swarm in large numbers, they mate with the wild female flies, which end up laying unfertilized eggs, thus lowering the swarm population.
Tackling NWS swarms is crucial since they pose a major threat to livestock. In an Aug. 15 statement, USDA called NWS a โdevastating pest.โ
โWhen NWS fly larvae (maggots) burrow into the flesh of a living animal, they cause serious, often deadly damage to the animal. NWS can infest livestock, pets, wildlife, occasionally birds, and in rare cases, people,โ the agency said.
โIt is not only a threat to our ranching community, but it is a threat to our food supply and our national security.โ
Since May, U.S. ports have been closed to imports of cattle, horses, and bison from Mexico to prevent the spread of NWS flies into the United States.
Rollins accused Mexico of having โfailed to enforce proper cattle movement controls and neglected to regularly maintain fly traps as agreed, undermining detection efforts.โ
โThis is unacceptable,โ she said in the post on X. โMexico must immediately implement agreed-upon protocols, expand surveillance, and restrict cattle movement in infected zones. For the foreseeable future the border will remain closed.โ