Fruit Fly Booklet

Fifty years of fruit fly eradication in South Australia: 1947-1997

The South Australian Government has prevented the establishment of fruit flies in this state for the past 50 years by a policy of prevention of entry of infested fruit, early detection of fruit flies which have been introduced, and eradication of outbreaks before they become established populations. This is a history of a unique operation which has allowed South Australians to grow fruit without it being spoiled by these pests, and also allows South Australian fruit to be exported as “fruit fly free”. © Primary Industries and Resources SA.


For 100 years, South Australian fruit growers have urged the Government to maintain a policy of excluding fruit fly from this state, and the Government has accepted this responsibility. The first introduction of fruit flies occurred 50 years ago, perhaps as a result of increasing movement of traffic into the state during and after the Second War. Outbreaks of fruit flies in the past 50 years have been predominantly two species, Queensland fruit fly (Qfly) and Mediterranean fruit fly (Medfly).

South Australia does not have an endemic population of any pest species of fruit fly although it is likely that some species of fruit fly could establish in South Australia if they were introduced but not detected and eradicated. The two economically important fruit flies need a sequence of host plants to increase and carry over populations during winter. The most favourable sequence of crops, starting in spring, are: loquat, apricot, early, middle and late peaches, quince, pear, apple early, midwinter and late-winter oranges, Valencia orange. This sequence of fruiting occurs in many cities and towns in South Australia and this, together with a favourable climate, indicates the likelihood of establishment of permanent populations of both species of fruit flies if they are not actively eradicated.

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Page Last Reviewed: 20 Nov 2017
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