An investigation of fruit flies (Trypetidae: Diptera) in Queensland. 1. Introduction, species, pest status and distribution

Abstract

The early history of fruit flies in eastern Australia, their identification, pest status and distribution, are reviewed. Evidence is presented that the Queensland fruit fly (Strumeta tryoni (Froggatt)), the most important Dacinae in Australia, was a pest of commercial fruit at least as early as 1853, and prior to 1900 was indigenous to an area in eastern Australia not greatly different from that recorded today.
Fifty-four species of Dacinae are recorded from Queensland. To facilitate the identification of these, studies of diagnostic characters were undertaken. These involved a general appraisal of characters and variations for all species.
The significance of colour variation associated with age of specimen when captured, and host, was investigated for S. tryoni and recorded for other species. Differences in the development of melanin in cutaneous layers were associated with nutrition during larval development, while alterations in subcutaneous markings were a function of age.
A limited statistical study of wing and ovipositor measurements of S. tryoni revealed the limitations of these characters for diagnostic purposes.
A revised generic classification of the Dacinae primarily based on fusion or non-fusion of abdominal tergites is presented. This and other new concepts of generic classification have introduced synonymy. A new arrangement of genera is presented.
Descriptions of several Queensland Dacinae have been revised. These reveal, more clearly, differences among closely allied species and recognize aberrant and colour forms within species.
A list of species of Dacinae occurring in Queensland is given together with new or recent synonymy. A key to these species is presented which permits species determination without recourse to generic classification and overcomes complete reliance on chaetotaxic and secondary sexual characters. Identification is possible also should either sex be considered.
Pest status determined from records of damage to commercial fruit, host studies, field observations and marketing reports has enabled the grouping of species as major or minor pests or those of no commercial importance. Eleven Queensland Dacinae have been bred from commercial hosts; five of these are considered of major importance.
Locality records are presented for all Queensland species. Records for the better known are presented on maps; those for S. tryoni are given for eastern Australia, the remainder for Queensland only. The evidence demonstrates that S. tryoni is endemic to an area of eastern Australia from East Gippsland (Victoria) in the south to Cape York Peninsula (Queensland) in the north and extending inland to at least the western slopes of the Great Dividing Range. Other authentic records were obtained for isolated centres in western New South Wales and Queensland and the Northern Territory.