The New World screwworm doesn’t simply feed on something that’s already dead. Its larvae invade wounds and feed on the living flesh of warm-blooded animals.
That disturbing fact is part of what made the parasite such a nightmare for American ranchers and wildlife managers before it was eradicated from the United States decades ago. Now, in 2026, New World screwworm has returned to the U.S. mainland, and the battle to stop it has taken on new urgency.
But what if one of the next weapons against this flesh-eating parasite isn’t simply more traps, treatments or sterile flies?
What if it’s genetics?
That’s the subject of Episode 80 of the Dark Outdoors podcast, featuring a conversation between Chester Moore and Matt James of Colossal Biosciences about the potential for advanced genetic technologies to become part of the fight against New World screwworm.
Listen to Episode 80
Apple Podcasts:
https://podcasts.apple.com/us/podcast/can-genetics-stop-the-screwworm-a-new-weapon/id1630809603?i=1000782125719&l=vi
Spotify:
https://open.spotify.com/episode/7fY1j5Z4gZqCJxCvtLOzpU?si=bafec6ea94c845e9
A New Kind of Weapon
For generations, one of the most effective weapons against New World screwworm has been the sterile insect technique.
Enormous numbers of sterile male flies are produced and released into areas where the parasite is present. Females that mate with those sterile males produce no viable offspring, allowing authorities to suppress the population.
It was an extraordinary biological weapon against an extraordinary parasite, and sterile insect releases remain central to the fight today.
But biotechnology has advanced dramatically since the original screwworm eradication campaign.
Colossal Biosciences has publicly discussed the potential for genetic biocontrol and gene-drive technology to be applied to New World screwworm. Instead of relying exclusively on repeated releases of sterile flies, advanced genetic techniques could potentially introduce traits designed to interfere with reproduction and spread those traits through a population.
That possibility is at the center of Moore’s conversation with James.
The discussion examines what these emerging technologies might mean, how genetics could potentially complement existing eradication methods and where the science could go from here.
Wildlife Could Pay the Price
This parasite is often discussed as a livestock problem, but cattle aren’t the only animals at risk.
New World screwworm can infest warm-blooded animals when female flies lay eggs in wounds. That puts wildlife in a particularly difficult position because wild animals can’t be routinely inspected the way livestock can.
A deer injured while fighting, a wild sheep wounded on the landscape or another animal suffering even a relatively small injury could potentially become infested.
The United States has already seen what screwworm can do to wildlife.
When New World screwworm appeared in the Florida Keys in 2016, endangered Key deer were hit hard. That outbreak remains an important warning about what can happen when the parasite reaches a vulnerable wildlife population.
The return of screwworm to the U.S. mainland makes the development of every effective control tool worth watching.
Genetics and the Future of Conservation
The larger question explored in Episode 80 goes beyond screwworm.
Modern biotechnology is creating possibilities for wildlife conservation that would have sounded like science fiction not long ago. Scientists are exploring genetics as a way to preserve endangered species, restore genetic diversity and address biological threats.
Screwworm turns that idea around.
Could some of the same rapidly advancing genetic technologies being considered to help wildlife also be used against an organism capable of devastating wildlife and livestock?
There are enormous scientific and ecological questions surrounding these technologies, and no single approach replaces the proven methods already being used against this parasite.
But the possibilities are fascinating.
The New World screwworm is back.
Could genetics help send it away again?
Listen to Dark Outdoors Episode 80: “Can Genetics Stop the Screwworm? A New Weapon Against a Flesh-Eating Parasite” on Apple Podcasts and Spotify.
Related Dark Outdoors Screwworm Coverage
New World Screwworm Resource Center
Follow Dark Outdoors’ continuing coverage of the screwworm threat, wildlife implications, interviews and new developments.
https://darkoutdoors.com/new-world-screwworm-resource-center
Texas Faces Screwworm. The Key Deer Did 10 Years Ago
Chester Moore talks with Dr. Roel Lopez about the devastating 2016 Key deer outbreak and what that experience could teach us about protecting wildlife today.
Flesh-Eating Screwworm Is A Huge Threat — And It’s Back In America
Legendary wildlife biologist Larry Weishuhn discusses his firsthand experience with screwworm and why the parasite’s return deserves serious attention.
About Dark Outdoors
Dark Outdoors investigates terrifying encounters, unsolved mysteries, true crime and dangerous wildlife.
Hosted by award-winning wildlife journalist Chester Moore, the podcast explores the stories, threats and mysteries found where people and the wild intersect.
Because the outdoors has a dark side.
Chester Moore
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Email Chester at chester@chestermoore.com.