The United States Department of Agriculture (USDA) has confirmed that the New World screwworm fly has reached south Texas, marking a significant expansion of the invasive species in North America. The fly, whose scientific name is Cochliomyia hominivorax, poses a serious threat to livestock, wildlife, and occasionally humans, as its larvae feed on living tissue.
USDA confirmation and response
The USDA announced the discovery on June 3, 2026, after identifying the fly in samples collected from the region. Officials emphasized that the fly's presence could lead to severe economic losses for the livestock industry if not contained. The agency is working with state and local authorities to implement surveillance and control measures, including the release of sterile flies to reduce the population.
Impact on agriculture and wildlife
The New World screwworm fly is a parasitic pest that infests warm-blooded animals, causing wounds that can be fatal if untreated. Infestations can lead to decreased livestock productivity, increased veterinary costs, and significant mortality in wildlife populations. The USDA is urging ranchers and veterinarians to report any suspicious cases to prevent further spread.
This is not the first time the screwworm has appeared in the United States. Eradication efforts in the 20th century successfully eliminated the pest from the country, but recent re-infestations in Florida and now Texas highlight the ongoing risk. The USDA's sterile insect technique program has been a key tool in managing the pest, but continued vigilance is essential.
Residents in affected areas are advised to monitor their animals for signs of infestation, such as maggots in wounds, and to seek veterinary assistance immediately. The USDA will provide updates as the situation develops.
