Key to Families of Australian Aquatic Diptera Larvae

Diptera comprises the true flies, that is those flies in which the adult has only one pair of wings, situated on the meso- (second) thoracic segment. The “wings” of the third (meta-) thoracic segment are modified as balancers of halteres. The name “fly” is attached to the common names of many flying insects, such as whitefly, caddisfly, alderfly and mayfly, none of which are dipteran flies. Common true flies include the mosquitoes, midges, gnats, black flies, crane flies, horse flies, hover flies, house flies and blow flies.

The order Diptera ranks amongst the largest in the Insecta, with a very wide range of adult and larval diverse biologies demonstrated. Many true flies have aquatic immature stages. These include many families of medical significance in the adult stage, as human biters and vectors of disease, such as mosquitoes and black flies and many gnats, midges and horse flies. Because of the public health significance of many flies, the immature stages are often better known than the immature stages of other insects. Thus there are identification manuals to genus and species level for the mosquitoes and chironomid midges from many regions of the world, and the ecology of many immature stages may be quite well known.

Aquatic Diptera larvae include filter feeders, either planktonic (Chaoboridae, Culicidae), in the surface meniscus (Dixidae), attached to the substrate (Simuliidae, Blephariceridae) or free-ranging (Ephydridae). Amongst other aquatic dipteran larvae, detritivory and saprophagy in the benthic depositional substrates is very common (many Chironomidae, Tipulidae, Psychodidae, Tabanidae). Predation is found in some Chironomidae, Ceratopogonidae and many aquatic Empididae, Dolichopodidae and Muscidae). Specialised aquatic habitats include snail parasitism (Sciomyzidae) and thin water films (the hygropetric or madicolous zone) provides a home for some grazers (Thaumaleidae, some Psychodidae).

Key Author(s): CSIRO Entomology Key Version: 1.1