A review of gall midges (Diptera: Cecidomyiidae: Cecidomyiinae) of Australia and Papua New Guinea: morphology, biology, classification and key to adults

The subfamily Cecidomyiinae are dipteran midges whose larvae feed on plants, insects, arachnids or fungi. Most Cecidomyiinae are plant feeding with the majority inducing infestation symptom called a gall. A gall is a malformation, often spectacular in form and colour, that is formed instead of or on the attacked plant tissue. In the strict sense Cecidomyiinae are the true gall midges although the vernacular term is used commonly for the whole Cecidomyiidae family. Cecidomyiinae contain a variety of species of economic importance. Many gall midges are pests of plant crops while others are used as biological control agents of weeds, insects or mites. This paper provides a guide to taxa occurring in Australia and Papua New Guinea. An overview of morphology of larvae, pupae and adults is given. Typical life cycles are exemplified. Listed are species that are pests in forestry, horticulture and agriculture as well as species that are beneficial as plant pest predators. Furthermore, listed are native species that are in use overseas against weeds and insect pests of Australian origin and non-indigenous species that were introduced into Australia to control alien weeds. A key to adults of genera occurring in Australia and Papua New Guinea is provided. Included are taxa that are native as well as those that have been introduced unintentionally as plant pests or intentionally as biological control agents of weeds. Taxonomic classification of genera and references to species are given. Cecidomyia omalanthi-Skuse, 1890 is renamed Okriomyia omalanthi (Skuse, 1890) comb. nov. Resseliella oleisuga (Targioni-Tozzetti, 1887) feeding on the bark of introduced olive Olea europaea is reported from Australia for the first time.