Jessica Metcalf at Colorado State University studies the odors produced by infected wounds to develop improved traps for the New World screwworm, a parasitic fly that devastates livestock and wildlife across the Americas.
The New World screwworm (Cochliomyia hominivorax) lays eggs in open wounds on living animals. The larvae then burrow into flesh, causing severe tissue damage and often death if left untreated. The pest costs the livestock industry millions annually and threatens wild populations across Central and South America, Mexico, and occasionally the southern United States.
Metcalf's approach focuses on the chemical signatures that wounds emit. These odors attract gravid females seeking suitable egg-laying sites. By analyzing and characterizing wound volatiles, her team aims to create synthetic lures that replicate natural scent profiles more accurately than current traps.
Traditional control methods rely on the sterile insect technique, where sterilized males are released to mate with wild females, preventing reproduction. While effective in some regions, this approach requires continuous breeding and release of millions of insects. Better traps could complement or enhance this strategy by providing early detection and direct population control.
The research combines analytical chemistry with entomology. Metcalf's team collects volatiles from infected wounds and uses gas chromatography and mass spectrometry to identify the compounds attracting screwworms. Understanding which odor components drive fly behavior allows researchers to refine synthetic baits for field deployment.
This work carries practical implications for ranchers in endemic and at-risk regions. More effective traps reduce livestock losses without relying solely on labor-intensive sterile insect programs. The research also supports wildlife conservation efforts in countries where screwworm infestations threaten endangered species.
Limitations include variability in wound chemistry based on infection stage, animal species, and environmental conditions. Laboratory findings must translate