Australian Diplectroninae reviewed (Insecta: Trichoptera), with description of 21 new species, most referred to a new genus.

The history of studies on Australian caddisflies in the hydropsychid subfamily Diplectroninae is outlined against a broader background of uncertainties in the delineation of the worldwide type genus, Diplectrona Westwood. For the Australian fauna, keys are given to genera of Diplectroninae that occur in Australia and to adult males of species in Diplectrona (including a newly synonymised genus, Diemeniluma Neboiss), Austropsyche Banks, and Arcyphysa gen. nov. Of the 32 diplectronine species recognised, six are referred to each of Diplectrona and Austropsyche, among them one and four newly described species, respectively; and four established species are transferred from Diplectrona to Arcyphysa gen. nov., to join 16 newly described species. Diplectrona cognata Banks is synonymised with D. spinata Banks and Diplectrona bispinosa Jacquemart with Austropsyche victoriana Banks. Diagnoses and descriptions are accompanied by line drawings illustrating most of the diagnostic features of the genera and of most species, supplemented by photographic images. Australian species of Diplectrona are found from south-eastern Queensland to Tasmania, but neither Austropsyche nor Arcyphysa is known from Tasmania. Austropsyche extends from the Grampians in south-western Victoria to south-eastern Queensland, and the majority of species of Arcyphysa are recorded from north-eastern mainland Australia.