The mission of the Subtropical Exotic Pest Insect Research Unit (STEPIRU) is to develop effective, environmentally-safe methods to diminish the risk of introduction of pest insects from the Caribbean, Central and South America into the US through Florida. The establishment of the USDA exotic insect pest Unit in Miami represents an innovative change from a reactionary to a pro-active approach in protecting our agriculture.

In April 1965, larvae and adults of the Caribbean fruit fly, Anastrepha suspensa, were found near the Miami International Airport. As a result in 1968 the Subtropical Horticulture Research Station at Chapman field was selected as a location for work developing methods of control for this pest. Initial studies were concerned with mass rearing and sterile release programs. Further work was initiated on commodity treatments for potentially infested fruits and vegetables. A number of successful treatments have resulted from work at the Miami laboratory. Additional work on other insects of quarantine importance and the Caribbean fruit fly is underway.

The Caribbean fruit fly colony was started from flies collected from various Florida subtropical fruits in 1965. The first larval diet was developed at the USDA lab. set up near Opa Locka airport in 1965. In 1966, the colony was turned over to the Florida Department of Agriculture in Homestead under R. M. Baranowski. In 1968, the ARS laboratory at Miami took over rearing and an agar based diet was developed. The same strain has been perpetuated, with a few changes in the diet and a few additions of wild flies, to the present.