Mexico, Central America, and South America. Knipling developed the theory of autocidal control – breaking the pest's reproductive cycle. Bushland's enthusiasm for Knipling's theory sparked the pair to search for a way to rear flies in a "factory" setting, and to find an effective way to sterilize flies. Their work was interrupted by World War II, but they resumed their efforts in the early 1950s with successful tests on the screw-worm population of Sanibel Island, Florida. The sterile insect technique worked; near eradication was achieved using X-ray-sterilized flies. Successes In 1954, the technique was used to eradicate screw-worms from the island of Curaçao, off the coast of Venezuela. Screw-worms were eliminated in seven weeks, saving the domestic goat herds that were a source of meat and milk. During the late 1950s to the 1970s, SIT was used to control the screw-worm population in the US. In the 1980s, Mexico and Belize eliminated their screw-worm problems with SIT. Eradication programs progressed across Central America in the 1990s, followed by the establishment of a biological barrier in Panama to prevent reinfestation from the south. The map shows the current and former distribution area and the approximate seasonal spread of the screw-worm fly. In 1991, Knipling and Bushland's technique halted a serious outbreak of New World screw-worm in northern Africa. Programs against the Mediterranean fruit fly in Mexico, Florida and California use the SIT to maintain their fly-free status. The technique was used to eradicate the melon fly from Okinawa and in the fight against the tsetse fly in Africa. The technique has suppressed insects threatening livestock, fruit, vegetable, and fiber crops. The technique was lauded for its environmental attributes: it leaves no residues and has no (direct) negative effect on nontarget species. The technique has been a boon in protecting the agricultural products to feed the world's human population. Both Bushland and Knipling received worldwide recognition for their leadership and scientific achievements, including the 1992 World Food Prize. The technique were hailed by former U.S. Secretary of Agriculture Orville Freeman as "the greatest entomological achievement of the 20th century." African trypanosomiasis Sleeping sickness or African trypanosomiasis is a parasitic disease in humans. Caused by protozoa of genus Trypanosoma and transmitted by the tsetse fly, the disease is endemic in regions of sub-Saharan Africa, covering about 36 countries and 60 million people. An estimated 50,000 – 70,000 people are infected and about 40,000