Success in Curaçao Attracts Attention

Photograph "Purebred Brahma Cattle on a Pangola Grass Pasture

Photograph "Purebred Brahma Cattle on a Pangola Grass Pasture."

The success in Curaçao and the activities of the Orlando facility attracted more and more attention in the United States. Interest by ranchers and other livestock producers gave rise to hope that a full-scale screwworm eradication project would start soon in the Southeast United States, with a focus on Florida. Researchers at Orlando and other USDA labs began planning for such a program.


Florida's Campaign to Fund Eradication

Florida livestock producers began a grassroots campaign of the state legislature and the United States Congress to fund an eradication program. The effort was led by the Florida Cattlemen's Association and its president, J.O. Pearce. In April 1957, the state legislature appropriated $3 million for an eradication program.

Matching Funds for Florida Program

The Agricultural Research Service (ARS) team that surveyed the screwworm situation in Florida returned a report strongly supporting an eradication strategy for the entire Southeast. Congress heard testimony in 1956 from USDA scientists, including Edward F. Knipling, who promoted the effectiveness of the Sterile Insect Technique (SIT). Congress allocated matching funds for the program, $1.6 million the first year.

Florida Eradication Key to the Southeast

A significant factor contributing to the successful eradication of the screwworm in the Southeast was the region's geography. With the Gulf of Mexico and the Caribbean Sea as a barrier to infestation from beyond U.S. borders and since overwintering screwworm populations were limited to the Florida peninsula and southern Georgia, eradication in these two areas would free the entire southeastern United States from the screwworm. Careful inspection of livestock moving into the Southeast from beyond the Mississippi would prevent reinfestation from the West.

Mainland Florida Used as a Program Test Site

The Florida legislature provided some limited funding through the Florida Livestock Board for a test area of mainland Florida. In 1957, SIT was used in a 2,000-square-mile area east of Orlando. Eradication reached 70 percent. This project helped the scientists estimate the resources needed to rid the whole state of screwworms.

New Fly-Rearing Facility at Bithlo, Florida

To produce the immense number of sterile flies needed to cover the Orlando East project and then the whole Florida peninsula, new fly-production facilities were needed. A larger facility was built in Bithlo, Florida.

Constant Efforts to Improve Fly Rearing

The Bithlo facility allowed more room for research, much of it focused on improved fly production. The staff wanted to produce hardy flies that would compete with fertile flies in the wild. Early on it was obvious that larger larvae meant larger, more competitive flies. Research to determine the best food for growing larvae was, and remains today, a key concern. Attempts to provide the best nutrition for the larvae at the least possible cost led to many experimental feeding mixtures, including honey, beef hearts, and whale meat.

Raymond C. Bushland Urges "Spent" Screwworm Media Be Used as Hog Feed

One of the greatest—and smelliest—problems that confronted staff was the disposal of waste from the feeding media used for the larval stage. Workers replaced the media every few hours so the larvae would continue feeding. Bushland suggested the possibility of converting the media into hog feed. Veterinarian R.D. Radeleff replied, "Even a hog draws the line at some things."

The Southeast Eradication Project

Science Pays Off

Speech (transcript). 1958 July 24. "Science Pays Off."

The Southeast eradication project was to start at the end of 1958, after construction of the newest and largest production facility in Sebring, Florida, and while the screwworms overwintered in the Florida peninsula. The winter of 1957-1958, however, was extremely harsh, forcing the screwworms to overwinter in a relatively small area at the southern end of the peninsula and enabling early and inexpensive completion of the project. Since the Sebring facility was not finished, production was stepped up in Bithlo and Orlando to get sterile flies ready for the first releases in January 1958.

Sebring Plant Produces 50 Million Flies Per Week

By the middle of 1958, the Southeast eradication program was in full swing, with aerial drops of sterile flies, a large public information campaign to foster cooperation with livestock owners, and quarantine laws in place. In July 1958, the large Sebring fly production facility opened in an old airplane hangar. It was capable of producing 50 million flies a week, enough sterile flies to inundate Florida.

Combined Efforts Essential to Eradication in Florida

A system of 400 fly traps baited with decaying liver was maintained throughout Florida and its border areas to determine where and how quickly the fertile fly population diminished. Data from the traps indicated which areas needed more sterile flies or were screwworm free. C.C. Skipper, an expert in fly traps, developed more effective traps for the Florida project. Livestock producers, county agents, and others added to the data by making reports of screwworm infestations.

Southeast Free of Screwworms

By early 1959—one year after the eradication program started and a year ahead of schedule—scientists claimed success in Florida and the Southeast United States. There were setbacks, however: quarantine regulations were hard to enforce and small reinfestations were reported in Florida, southern Alabama, and Louisiana. The infested areas were quickly saturated with flies, and the outbreaks were successfully controlled.