These studies were designed to investigate the field ecology of fruit flies in Queensland and so provide a more complete knowledge of these pests. A knowledge of species, their taxonomic relationships and certain aspects of bionomics were complementary to the field studies. All this information would provide a sounder basis for initiating and evaluating control measures. The early history of fruit flies in Australia has been traced from the literature and unpublished data. Strumeta tryoni (Frogg.) was a widespread pest of fruit in New South Wales and Queensland by 1853, ranging from south of Sydney to northern Queensland. A review of earlier studies in Australia of the taxonomy, ecology and economic aspects of fruit flies is presented together with an account of control measures employed against fruit flies overseas which may have application to the problem in Queensland. Species of importance, their economic status and problems of control in Queensland are discussed. Six of the eleven species of Dacinae bred from economic fruits are considered of primary importance. A key to the fifty two species of Dacinae recorded from Queensland is presented. Variation between species as well as within a species within districts was determined in a limited statistical study. Ratios derived from measures of portions of the wing and ovipositor were used for comparisons.Differences between ratios were of no practical value tor differentiating species nor identifying individual specimens with districts. ..........................