Screwworm flies (Cochliomyia hominivorax) were eradicated from North and Central America over the latter half of the 20th century. Keeping the flies and their flesh-eating larvae away saves saves U.S. an estimated $1.3 billion in damage to livestock every year. The adult flies shown here are laying eggs at COPEG, the Panama – United States Commission for the Eradication and Prevention of Screwworm, which mass rears sterilized screwworm flies to maintain a permanent sterile fly barrier in eastern Panama to supply sterilized screwworms for outbreak response elsewhere. (Photo credit: USDA-APHIS)