Fruit Flies (Diptera: Tephritidae)

The Fruit Fly Problem

There are fruit pest tephritids in almost all fruit growing areas of the world and their economic importance can be summarized as follows:

  • They attack commercially produced fruit;
  • Some species have become pests in regions far removed from their native range;
  • Quarantine restrictions have to be imposed to limit further spread of fruit fly pests;
  • Quarantine regulations imposed by an importing country can either deny a producing country a potential export market, or force the producer to carry out expensive disinfestation treatment.

Monetary estimates of fruit production and fruit fly damage are not available for most countries. However, Australia may be taken as an example, with annual fruit production running at over A$850 million and potential losses believed to exceed A$100 million if fruit flies were not controlled (Anon., 1986). The costs of a fruit fly free area being invaded are even greater, e.g. Dowell & Wange (1986) listed eight species that are a major threat to California, and estimated that the statewide establishment of those species would cause crop losses of US$910 million and cost US$290 million to control. The cost of eradicating a fruit fly from even a small island is very large. For example, it cost Japan Y5 billion (about US$32 million) and 200,000 man days work to eradicate the Oriental fruit fly, Bactrocera dorsalis (Hendel), from its south-western islands using the sterile insect release method (Anon., 1986). It is therefore very important that quarantine entomologists can make rapid identifications of fruit flies intercepted with imported fruit produce, so that measures can be taken quickly to try to prevent the establishment of new fruit fly pests. Details of import restrictions are too numerous and rapidly changing to be included here, and publications produced by national agricultural departments, the Food and Agriculture Organization of the United Nations (FAO) and journals such as Citrograph, should be consulted. Private travellers usually fail to understand the need to abide by regulations banning the import of fruit. The incidence of infested fruit in aircraft baggage has been discussed by Satoh et al. (1985).

Anon. (1986) Report of the expert consultation on progress and problems in controlling fruit fly infestation, Bangkok, 1986. RAPA Publication, 1986(28), 1-18. Food and Agriculture Organisation, Regional Office for Asia and the Pacific, Bangkok.

Dowell, R.V. & Wange, L.K. (1986) Process analysis and failure avidance in fruit fly programs, In: Mangel, M., Carey, J.R. & Plant, R.E. (eds), Pest Control: operations and systems analysis in fruit fly management. NATO Advanced Science Institutes series G: Ecological Sciences, 11, 43-65. Springer Verlag, Berlin.

Satoh, I.,Yamabe, M., Satoh, S. & Ohki, A. (1985) Study of the frequency of finding of the fruit flies infesting the fruit imported as air baggage. Research Bulletin of the Plant Protection Service, Japan, 21, 71-73. [RAE 74:3454]