Web Content Viewer (JSR 286)



Obnoxious and destructive, the screwworm, Cochliomyia hominivorax (Coquerel), is the only insect known to consume the living flesh of warm-blooded animals. It has caused immeasurable suffering and losses in livestock, wildlife, and even human populations the world over.

USDA utilizes alternative screwworm control measures, sterile fly irradiation, with the goal of reducing or eliminating the insect population.  It has successfully eliminated screwworm from the United States and Mexico and maintains a border at the Darian Gap in Panama to prevent reinfestation.  Reducing or eliminating the fly population has proved to be a much more effective solution than treating the pests topically after entry into hosts via skin wounds.

screwworm larvae (Cochliomyia homnivorax)

Using sterile fly technology, fertile females mate with sterilized males mass-reared in insectaries and released into infested areas. With offspring resulting only from matings with native, unsterilized males, the screwworm population gradually becomes insignificant and may eventually disappear.

The sterile insect approach eradicated the screwworm from the U.S. in 1966. Since 1991, Mexico and several countries in Central America have been declared free of screwworm: Belize, Guatemala, El Salvador, Honduras and Nicaragua.

History of the Screwworm Program

Screwworm Program Staff



Additional Information