he Queensland fruit fly, Bactrocera tryoni (Froggatt), occurs in climates ranging from temperate to tropical. Within its range, it is one of the most important pests with which pome and stone fruit growers have to contend, and at times it has been a very destructive pest of citrus. Bactrocera tryoni appears to be almost as destructive to fruit production in its Australian range as the oriental fruit fly, Bactrocera dorsalis Hendel, is in countries where it appears.