Even the name is horrific: New World screwworm fly. Officials say the flesh-eating parasite is buzzing north from Mexico and could soon enter the United States. So scientist hatch a plan to battle insects with insects.
The New World screwworm fly (NWS) is a harmful pest. Adults resemble common houseflies but with shiny green or blue bodies, burnt orange eyes, and three dark stripes. NWS can infest livestock, pets, wildlife, and sometimes humans.
Female flies lay eggs in wounds of warm-blooded animals. Larvae hatch and begin feeding on live flesh and fluids instead of dead material like most flies do. Ugh.
The fly’s unpleasant name refers to how its larvae feed. When entering a wound, maggots chomp-chomp-chomp with sharp hooks. They burrow into flesh like a screw into wood. Other maggots join the feeding frenzy. NWS invasions can cause serious, even deadly, damage to flocks and herds.
God’s creation at Genesis was perfect. But sin means dealing with its consequences—like cattle pestilence and invasive species. Thankfully, there are ways to battle this one.
The United States mostly eradicated the NWS pest in the 1970s. Lab workers did so by breeding and releasing sterile male flies to breed with wild females. The lab-grown male flies caused female flies to lay eggs that would never hatch. Since female NWS mate only once in a life cycle, the NWS population eventually dies out.
The plan kept NWS flies contained in Panama for years . . . until southern Mexico sightings late last year.
In May, U.S. officials closed the southern border to live cattle, horse, and bison imports. They planned to reopen several entry points by mid-September. Then the flesh-eating fly showed up farther north than anyone expected—about 370 miles from the Texas border.
American officials say that if the fly reaches Texas, NWS maggots could cause huge economic losses.
Mexico’s President Claudia Sheinbaum suggests the United States is exaggerating the threat to its beef industry from NWS parasites. She claims Mexican authorities are following protocols to deal with the northernmost case.
But U.S. Department of Agriculture Secretary Brooke Rollins isn’t waiting around to be invaded. She announced plans for combating the parasite, including a new site for breeding more sterilized male flies.
The U.S. Department of Agriculture hopes a new fly factory will be up and running in southern Mexico by July 2026. The agency also plans to open a site in southern Texas for holding sterile flies imported from another fly factory in Panama. They’ll release billions of sterile flies along the border if the flesh-eating insects keeping coming.
Why? Adam’s sin affected the perfect balance God created. Now part of human dominion over creation (Genesis 1:28) is trying to manage sin’s consequences.
