Two more cases of the New World screwworm have been confirmed hundreds of miles apart in Texas, demonstrating the difficulty of stopping the spread of a pest that could potentially devastate the nation's cattle industry, the U.S. Department of Agriculture announced Monday.
The screwworm is actually a fly larva that eats living flesh instead of dead material. Females lay their eggs in open wounds of warm-blooded animals like cattle, but wildlife, pets and occasionally even humans can be infested. A government program to breed sterile male flies and drop swarms of them from planes to mate with wild females had kept screwworm contained at the southern end of Panama for decades.
So far, there are four confirmed cases in Texas. The USDA said the latest were a calf and a dog in La Salle and Andrews counties, respectively. The initial screwworm cases were discovered last week in two calves within a few miles of each other in south Texas.
