TEXAS — The U.S. Department of Agriculture announced $105 million in funding for 40 projects to improve defenses against the New World screwworm. The announcement supports research and containment efforts following the parasite's re-emergence in the southwestern United States.

Colorado State University received funding from the USDA for a project to study New World screwworm attraction. Jessica Metcalf, a professor at Colorado State University, is studying foul-smelling substances to determine what attracts the parasite to open wounds. The New World screwworm was eradicated in the United States more than 50 years ago, but the parasite was found in Texas in early June 2026.

As of July 23, 2026, the New World screwworm parasite has been detected in cattle, sheep, goats, and two dogs in Texas. The parasite was also detected in one dog in New Mexico.

The New World screwworm is a type of blowfly that lays eggs in wounds and body openings. The resulting maggots feed on living tissue, and the parasite can infest any warm-blooded animal, including people and pets. Left untreated, the New World screwworm parasite can be deadly.

Foul odors are chemical byproducts of bacteria. "We use these bacterial cues to stay away from certain things -- to not eat spoiled meat, for example," Metcalf said. "The insects are using them for a different reason. They're like, 'Yes, bring it, that smells like a great place to lay eggs.'"

One widely used lure for screwworms utilizes bacterial-produced smells from rotting meat. These lures attract the secondary screwworm, which prefers dead flesh, and traps filled with secondary screwworms make it difficult to detect the New World screwworm. Metcalf's project aims to develop lures specific to the New World screwworm using bacterial-produced smells from wounds.

Bacterial-produced smells are known as volatile organic compounds. Metcalf's team will distinguish the volatile organic compounds that attract the New World screwworm versus the secondary screwworm. The team will also distinguish which bacteria are found on the New World screwworm versus the secondary screwworm.

"Because we had been working on the relationship among insects, bacteria and animal decomposition for the last 15 years, and the New World screwworm evolved from a decomposer -- an insect that utilizes dead flesh to raise its young -- we were well set up to tackle this problem," Metcalf said. Blowflies carry bacteria that they use to communicate across the species, signaling to other blowflies where to find a suitable host.

Metcalf and her collaborators will enlist volunteers, including livestock producers, veterinarians, and wildlife biologists, to swab animal wounds for lab testing. Stakeholders in the project will receive diagnostic results from lab tests, information about the New World screwworm, sampling supplies, and training. The research team is leveraging statewide partners, including producer associations, state agencies, CSU Extension, CSU's Agricultural Experiment Station, and Veterinary Diagnostic Laboratories.

Project collaborators in Texas, Arizona, and New Mexico will conduct outreach and sampling. Tracey Goldstein, director of CSU's One Health Institute, will coordinate outreach, training, and sampling activities across the network.

"This particular fly doesn't care if you're a person, a deer, a pig or a chicken," Goldstein said. "It will infest everything, which is a little scary. That's also part of why it's hard to manage it. We really need all eyes and ears out there on the ground to help figure out if and when it gets to Colorado."

Julia Herman, a beef cattle specialist veterinarian with the National Cattlemen's Beef Association, will connect producers across the country with the research. Producers in infestation zones are required to check every animal for wounds, and wounds must be healed before livestock can be moved from infestation zones.

"We can't treat our way out of this problem," Herman said. "We have to have other ways to manage this fly, and this project provides a way that we can decrease New World screwworm fly populations." Herman noted that the parasite affects the cattle industry through animal welfare concerns, transportation challenges, and resource costs. "Hopefully we can take some of that stress off the producer and minimize the time and resource loss with projects like Dr. Metcalf's," she said.

The current international effort to manage the New World screwworm is largely based on irradiating male blowflies to make them sterile. The USDA and Panama's Ministry of Agriculture Development operate a facility in Panama that breeds, sterilizes, and releases New World screwworm blowflies. Female blowflies mate only once, and when they mate with sterile males, their eggs do not hatch.

The re-emergence of the New World screwworm in Texas and New Mexico marks a shift for a parasite eradicated in the United States more than 50 years ago. The USDA's $105 million investment in 40 projects reflects the scale of the response required to protect livestock, wildlife, and human health in the region.

Metcalf's research into species-specific detection lures addresses a gap in current monitoring tools, which often confuse the New World screwworm with the secondary screwworm. By distinguishing the bacterial and chemical cues unique to each species, the project aims to improve early detection and reduce the burden on producers who must inspect every animal for wounds.