Abstract
Immature stages of 43 species of Australian Hydroptilidae are described and figured for the first time: included are members of the genera Hydroptila, Hellyethira, Acritoptila, Acanthotrichia, Oxyethira, Tricholeiochiton, Orphninotrichia, Maydenoptila, and Orthotrichia. All available information on general biology is given and the functional and phylogenetic significance of larval adaptations are discussed.