The national fruit fly situation in Australia.
Although there are over 70 fruit fly species recorded from the Australian mainland, the majority of control activities concern two well-recognized pests, Queensland fruit fly (Q-fly) Bactrocera tryoni and Mediterranean fruit fly (Medfly) Ceratitis capitata. These two pest species are separated by extensive, inhospitable land areas interspersed with irrigated host crops. Some production areas can be declared "fruit fly-free" zones, which offers significant trade advantages. The State of South Australia has managed to maintain an area freedom status but incursions of either species regularly occur into this area and require eradication. The island of Tasmania does not support resident fruit fly populations although incursions have been detected in the past. These two pests cause major problems in ensuring that fruit and vegetables both sold within Australia and exported overseas are certified uninfested by fruit fly. Such declarations can be made if fruit is grown in a monitored area free zone, or if certain other conditions are met. The Certification Assurance and other Systems Approaches to fruit fly control are continually being refined to enable trading of fruit fly susceptible produce with minimal interruption. Other indigenous pests for which quarantine treatments may be required but are generally not listed in international trade agreements include B. cucumis, B. neohumeralis, B. jarvisi, B. musae and B. frauenfeldi. A range of fruit fly research and control activities is conducted in Australia. Some of these, including baiting and cover spray applications, are briefly listed in this paper.