Health and agricultural authorities are closely monitoring the spread of the New World screwworm, a dangerous parasitic fly whose larvae can infest and feed on the living tissue of warm-blooded animals. Recent detections in parts of Mexico have prompted increased concern among officials in the United States, particularly in southern border states such as Texas.
While no widespread outbreak has been reported within the United States, experts are taking preventative measures to stop the parasite from crossing the border and threatening livestock, wildlife, pets, and, in rare cases, humans.
What Is the New World Screwworm?
The New World screwworm is a parasitic fly whose larvae hatch from eggs laid in open wounds or mucous membranes of animals. Once the eggs hatch, the larvae burrow into living tissue and begin feeding, causing painful and potentially life-threatening injuries. Unlike many other fly larvae that feed on dead tissue, screwworm larvae attack healthy, living flesh. This unique behavior makes infestations particularly dangerous and difficult to treat if not detected early. The parasite was successfully eradicated from the United States decades ago through an extensive sterile-fly release program, which remains one of the most successful pest-control campaigns ever conducted.
The New World screwworm is a parasitic fly whose larvae hatch from eggs laid in open wounds or mucous membranes of animals. Once the eggs hatch, the larvae burrow into living tissue and begin feeding, causing painful and potentially life-threatening injuries. Unlike many other fly larvae that feed on dead tissue, screwworm larvae attack healthy, living flesh. This unique behavior makes infestations particularly dangerous and difficult to treat if not detected early. The parasite was successfully eradicated from the United States decades ago through an extensive sterile-fly release program, which remains one of the most successful pest-control campaigns ever conducted.
