Revision of Australian Matini diving beetles based on morphological and molecular data (Coleoptera, Dytiscidae, Matinae), with description of a new species

Morphological characters and mitochondrial DNA sequence data were used to revise the Australian diving beetles in the genera Allomatus Mouchamps, 1964 and Batrachomatus Clark, 1863. As a result of these studies Allomatus syn. n. is synonymised with Batrachomatus, and Allomatus nannup Watts, 1978 from SW Australia and A. wilsoni Mouchamps, 1964 from SE Victoria are transferred to Batrachomatus. The four Australian Matini species known so far are re-described, and B. larsoni sp. n. from the Windsor Tableland in NE Queensland is described. After more than 40 years B. wilsoni has been re-discovered in two rivers in Victoria. We delineate the species using traditionally employed morphological structures such as in the male genitalia and body size, shape and colour pattern, as well as mitochondrial cox1 sequence data for 20 individuals. Important species characters (median lobes, parameres and colour patterns) were illustrated. We provide an identification key and outline distribution and habitat preferences of each species. All Australian Matini are lotic, inhabiting permanent and intermittent streams, creeks and rivers.