The Foreign Service Journal, April 2022

THE FOREIGN SERVICE JOURNAL | APRIL 2022 25 1929. With the advent of a serious FMD outbreak in Mexico in 1947, President Harry Truman signed a bill authorizing the U.S. Secretary of Agriculture to offer aid to “protect vital U.S. inter- ests.” USDA veterinarians worked with their Mexican colleagues to achieve eradication in that country by 1954. During this same period, two other highly significant pests were threatening U.S. agriculture, namely the NewWorld screw- worm (NWS) and the Mediterranean fruit fly (or medfly). To bring them under control, starting in the 1950s the U.S. devel- oped a technique for using radiation to sterilize the male fly of the screwworm. APHIS then worked with the International Atomic Energy Agency on its large-scale implementation. Build- ing on that success, the same strategy was later applied to the medfly. Eradication of both pests was achieved by decreasing the overall number of flies with conventional chemical sprays, followed by the release of sterile males to flood the “wild” male population and reduce the number of offspring. For more than six decades now, the United States has worked with foreign countries, as well as the IAEA, to gradually eradicate screwworm from the southern U.S. through Mexico, Guatemala, Honduras and El Salvador, then Nicaragua and Costa Rica, and on down to Panama, where an “insect barrier” is maintained by dispersing 4.7 million sterilized screwworms each week into the rainforest area of the Panama-Colombia border. For medfly, a containment barrier has been established in Guatemala, with as many as 1.3 billion sterile medflies being released each week. In both cases, cooperative agreements with Panama, Guatemala, Mexico and other countries ensure the smooth administration of the programs. Screwworms can infect any living, warm-blooded animal. This includes not only livestock and wildlife; screwworms can and have also infected people. (The screwworm’s scientific name is C. hominivorax , or “man eater,” after a horrific outbreak among prisoners on Devil’s Island, an infamous 19th-century French APHIS entomologist John Welch, at left, and Panamanian screwworm personnel collecting a myiasis sample from a calf in the Darién Provence of Panama in 2015. The USDA has been instrumental in building and maintaining a barrier against the New World screwworm in the Americas and pushing that barrier down through Panama. The map shows the progress of New World screwworm eradication programs by their start dates. COPEG USDA