| abstract | Leptus larvae (Acarina: Erythraeidae) of Australia and New Guinea, collected either free-living or ectoparasitic on Arachnida or lower Insecta, are comprehensively reviewed. For Australia the following new species are described. From Scorpionida: L. barmeedius, L. baudini, L. carduus, L. hitchcocki, L. korematus, L. pistoris, L. stnithi and L. urodaci; from Araneae: L. minno; from Insecta: L. norrisi (Archaeognatha); L. flindersi (Blattodea); L. cheesmanae (Phasmatodea); L. bankensis, L. calcar, L. cultellus, L. foliatus, L. lighti, L. pincheni and L. tindalei (Orthoptera, Acridoidea); L. batjallus, L. clavatus, L. clelandi, L. elderi, L. fisheri (Hemiptera); L. grossi and L. puniceus (free-living only); some of the preceeding species were also captured free-living. From Papua New Guinea the following new species are described: L. calcar (Acridoidea); L. cheesmanae (Orthoptera: ʼcricketʼ) (both of these species also from Australia); L. lorarius, L. scutellatus and L. triacanthus (free-living). Additional host and other records are given for previously described species, originally described as ectoparasites of Insecta: from Australia: L. bathypogonus Womersley (Acridoidea); L. cerambycius Southcott (free-living); L. charon Southcott (Araneae, Scorpionida); L. faini Southcott (Araneae); L. orthrius Southcott (Hemiptera); from Papua New Guinea: L. draco Southcott (Odonata, Acridoidea, Tettiginioidea, Phasmatodea, Hemiptera). Protonymphs are described of L. barmeedius, L. baudini, L. calcar, L. charon, L. flindersi, L. orthrius and L. smithi. Deutonymphs are described of L. calcar, L. charon, L. flindersi and L. smithi. A key is provided for the known larvae, protonymphs and deutonymphs of Leptus of Australia and Papua New Guinea. Teratological abnormalities are recorded for L. cultellus, L. fisheri, L. minno and L. urodaci. |