The U.S. Department of Agriculture has again halted imports of Mexican cattle into the United States due to the spread of the damaging livestock pest New World Screwworm in Mexico. Screwworms are parasitic flies whose females lay eggs in wounds on warm-blooded animals,

New cases of screwworms on July 8 in Veracruz, Mexico has caused the U.S. to close southern borders to livestock imports.

The U.S. has closed its southern border again to livestock imports, saying that a flesh-eating parasite has moved further north in Mexico than previously reported