By Andi Anderson
A serious threat is moving closer to livestock in the United States. The New World screwworm, a flesh-eating parasite, is raising concerns among ranchers and agriculture officials. Once eliminated in 1966, this harmful insect is now making a northward return from Mexico.
The screwworm is not a worm but a fly. Female screwworm flies lay their eggs in open wounds on living animals, including cattle. When the eggs hatch, the larvae burrow into the flesh and begin feeding. If left untreated, this can cause severe damage or even death within a week.
“This parasite literally eats the animal from the inside out,” said Colin Woodall, CEO of the National Cattlemen’s Beef Association.
To stop this threat, the U.S. Department of Agriculture (USDA) is reviving a successful method from the past called the sterile insect technique. This process involves raising large numbers of screwworm flies, sterilizing the male flies through radiation, and then releasing them into the wild.
Female screwworms typically mate only once. If a female mates with a sterile male, she cannot reproduce, leading to a gradual decrease in the fly population. This method proved effective in the 1960s and is now being prepared again as a safe and environmentally friendly alternative to chemical pesticides.
Currently, screwworms are moving north from Central America into Mexico. Because these flies can fly long distances—up to 300 kilometers in a lifetime—they pose a real threat to southern U.S. states, especially Florida, where warm climates help them survive year-round.
Researchers believe the same technique may also help control other pests, such as mosquitoes, though it does not work on all insects.
For now, efforts are focused on preventing the return of this dangerous parasite to protect U.S. herds.
Photo Credit: gettyimages-ahavelaar
Categories: Iowa, Livestock