Radiation of the microcaddisfly genus Orthotrichia (Trichoptera, Hydroptilidae) in Australia

Abstract

Orthotrichia is the most species rich of the hydroptilid genera found in Australia, and is postulated to be a relatively recent arrival from the Oriental Region. The genus has an almost worldwide but patchy distribution, represented by close to 280 species among which the Australian fauna of 55 species represents around 20%. In an attempt to understand the radiation of the genus in Australia, this paper explores the morphology and biology of Australian species and discusses a number of contrasts with reports on the biology of congeners in the Northern Hemisphere. The possible significance of these differences in Australian representatives of the genus is suggested to have played a role in the ‘success’ of the genus in the region. The value of life history studies to our understanding of biodiversity and biogeography is emphasized.