New World Screwworm Detected in South Texas

By Ryan McGeeney, University of Arkansas Division of AgricultureLITTLE ROCK — The U.S. Department of Agriculture announced last that the presence of a New World Screwworm (NWS) was confirmed in a calf in Zavala County, Texas, about 15 miles from the U.S.-Mexico border.The area is about 450 miles southwest of Texarkana, Arkansas. A 20-kilometer containment area has been established around the detection, halting the movement of livestock in and out of the area.While confirmation of the insect — a serious parasite of cattle and warm-blooded animals — in south Texas does not present a threat to the food supply, Arkansas ranchers are being advised to keep a close eye on their herds.Although the insect is largely discussed as a problem for cattle producers, Kirsten Midkiff, extension animal welfare specialist for the University of Arkansas Division of Agriculture, said it can affect “anything with a heartbeat,” including humans.According to the USDA’s Animal and Plant Health Inspection Service, the worm is “a serious pest that affects livestock, pets, wildlife, and less commonly, people and birds.”“It’s a danger to all livestock,” Midkiff said. “We hear a lot about it in cattle because we have huge cattle populations in Arkansas and Texas, but it has really ramped up on the wildlife side as well. We’ve seen it in deer and other animals.”Kelly Loftin, professor and extension entomologist for the Division of Agriculture, said the last notable incursion of NWS in the United States was in 2016-2017 in a population of Key deer in the Florida Keys.“Production livestock were not involved,” Loftin said. “NWS was eradicated by the spring of 2017 through vigilant surveillance, sterile male releases and preventative animal treatment.”The USDA recently updated its page dedicated to identifying and stopping the spread of screwworm.TransmissionMi...