Reduction in Fruit-Fly (Tephritidae, Dacinae) Populations in Their Endemic Rain-Forest Habitat by Frugivorous Vertebrates

Abstract

The reduction in larval populations of Dacus cacuminatus (Hering) and D. halfordiae (Tryon) by frugivorous vertebrates feeding on their major host fruits was studied in an endemic rainforest habitat in south-east Queensland. Throughout the spring and summer season, 66% of Solanum mauritianum Scop. fruit (D. cacuminatus host) was eaten by Macropygia phasianella (Temminck), the brown pigeon; this increased to 77% during the fruit fly's breeding season (November-January). The peak feeding time of the birds, the breeding season of the flies, and the peak fruiting season of the plants all coincided. Parasitism of D. cacuminatus by Hymenoptera, Biosteres kraussi (Fullaway) and B. oophilus (Fullaway), never exceeded 16-17%. Rodents consumed larvae in 78% of fallen fruit of Planchonella australis (R. Br.) Pierre (D. halfordiae host). It is proposed that frugivorous predators are the major natural enemies of larvae of tropical Tephritidae in their endemic habitat.