Citrus blackfly in Florida: Eradication or bio‐control?

The citrus blackfly (CBF) invaded south Florida in January 1976. It was considered by scientists to be a major threat to the Florida citrus industry located in the central part of the state. The CBF was successfully contained in a 1000 square mile tri‐county quarantined area surrounding Ft. Lauderdale for several months before breaking out to an area near the commercial citrus production area. During this time federal and state research agencies were evaluating a bio‐control approach involving two tiny wasps which were introduced in south Florida in 1976 by the United States Department of Agriculture. By late 1978 it had become clear to most of the leading scientists and some of the industry leaders that the spray program for eradication was failing and that research showed conclusively that the bio‐control agents (two wasps) could be a permanent solution to the problem. After considerable deliberation, research administrators announced on 18 January 1979 that they were convinced that the CBF was under bio‐control and was no longer a threat to the citrus industry. Although there was some resistance to giving up the concept of eradication with a spray program, it was announced on 8 March 1979, that the regulatory agencies would abandon the initial goal of eradication for a containment program and in August 1979 all spray programs were terminated. The bio‐control agents have successfully kept the CBF under bio‐control for 10 years. It was a low‐cost, environmentally sound solution of a serious threat to the Florida citrus industry. The decision to support a bio‐control program was approved (although perceived by some to be risky in 1979) and resulted in millions of dollars in savings to the people of Florida. Furthermore, since the bio‐control agents continue to be well established in Florida at low levels, the state can be assured it will not be invaded again by CBF. The success of the CBF bio‐control program engendered an increased credibility in this approach to management of other foreign pests. Increased emphasis on bio‐control research will lead to more applications in Florida as well as worldwide with benefits of cost saving and reductions to environmental degradation.