Revision of Australian Rheotanytarsus Thienemann & Bause (Diptera: Chironomidae), with emphasis on immature stages

Abstract

The immature stages of the genus RheotanytarsusThienemann & Bause (Diptera : Chironomidae) are abundant, diverse andecologically significant components of Australian flowing waters. The immaturestages (fourth-instar larvae and pupae) of the previously described speciesR. christinae Glover,R. flabellatus Glover, R. juliaeGlover, R. trivittatus (Johannsen) (a new senior synonymof R. johnstoni Glover) andR. underwoodi Glover are described for the first time.Four species are described as new: R. barrengarryensis,sp. nov.,R. gloveri, sp.nov.,R. oss, sp. nov., andR. petropholeter, sp. nov. (the last based on thedistinctive pupal stage alone). Illustrated identification keys are providedto all known adult males, pupae and larvae.

Two species previously allocated to Rheotanytarsus onthe basis of the female adult alone, R. ogilbyi (Skuse)and R. annulatus Glover, are transferred to thegenusTanytarsus Kieffer following detailed examinationof their genitalia. Both taxa remain unrecognised in any other life-historystage.

Adults of Australian Rheotanytarsus species emerge overextended periods (perhaps throughout the year), showing seasonal and diurnalvariation in time of day of emergence. They tolerate a range of aquaticpollutants, and utilise a wider range of low flow conditions than previously reported.