The genera of microgastrine braconid wasps present in the Australasian region (defined as Australia, New Zealand, New Caledonia, New Guinea, Solomon Is, Fiji Is, Samoan Is, Cook Is, but not French Polynesia) are reviewed. An illustrated key to genera, comments on their taxonomy, and information on the distribution and host relationships of species are provided. Following examination of holotypes, the generic placement of all species recorded from the region is reassessed since a recent generic reclassification of the subfamily left most of the Australasian species incorrectly placed. Parapanteles Ashmead (N.T.), Fornicia Brullé (Qld) and Deuterixys Mason (Qld) are recorded from Australasia for the first time, while Buluka De Seager, Parenion Nixon, Snellenius Westwood and Wilkinsonellus Mason, previously known from Australasia, are recorded from mainland Australia for the first time. The genus Austrocotesia is described as new [with A. exigua, sp. nov. (Papua New Guinea) as the type species], along with the following 14 species: Austrocotesia delicata, sp. nov. (Papua New Guinea, Qld), A. paradoxa, sp. nov. (Papua New Guinea), Buluka collessi, sp. nov. (Qld), Deuterixys anica, sp. nov. (Vic., N.S. W., Qld), Fornicia commoni, sp. nov. (Qld), Glyptapanteles deliasa, sp. nov. (S.A.), Microgaster nixoni, sp. nov. (Tas., N.S.W.), Parapanteles masoni, sp. nov. (N.T.), Parenion beelaronga, sp. nov. (Qld), P. bootha, sp. nov. (Qld), Sathon albicoxa, sp. nov. (Tas., Vic., N.S.W.), S. naryciae, sp. nov. (Vic.), Wilkinsonellus amplus, sp. nov. (Qld, N.T.) and W. tomi, sp. nov. (Papua New Guinea, New Britain, Qld). Glyptapanteles guyanensis (Cameron), comb. nov. is excluded from the Australasian fauna; the name Glyptapanteles fullawayi, nom. nov. (Samoa) is proposed for Apanteles opercuiinae var. polita Fullaway; lectotypes are designated for Cotesia deliadis (Bingham), comb. nov. (Qld), C. philoeampa (Cameron), comb. nov. (N.S.W) and C. rufiventris (Bingham), comb. nov. (Qld); Glyptapanteles operculinae (Fullaway), comb. nov. (Samoa), Microgaster kuchingensis Wilkinson (Papua New Guinea) and Sathon moratus (Wilkinson), comb. nov. (Vic., S.A., W.A.) are redescribed; and 41 additional new combinations are proposed.

The genera of Cardiochilinae are revised on the basis of a phylogenetic analysis of qualitative and morphometric characters. Partition homogeneity testing was used to evaluate the congruence between qualitative and morphometric data sets. Three most-parsimonious cladograms of 217.9 steps were found when morphometric characters were ordered and fractionally reweighted depending on the number of states. Sixteen monophyletic genera are recognised for the subfamily, with six described as new: Asiacardiochiles Telenga, stat. rev. (Australasian and Palaearctic)

The Australian and New Guinean species of the genera Microplitis Foerster and Snellenius Westwood are revised. Twenty species of Microplitis and three species of Snellenius are described as new, while Microplitis basalis (Bingham), M. demolitor Wilkinson, M. manilae Ashmead, M. perelegans (Bingham), Snellenius maculipennis (Szepligeti), S. philippinensis (Ashmead) and S. vollenhovii Westwood are redescribed. The genus Glabromicroplitis Papp (type species, Glabromicroplitis mahunkai Papp) is placed into synonymy with Microplitis. Information on the distribution of each species, host relationships where known, and taxonomic relationships are provided, along with an illustrated key to species. Aspects of the biology and host relationships of both genera are critically reviewed.

Abstract. The subfamily Cercobarconinae is synonymized with the Trachypetinae, the constituent genera (Trachypetus Guérin de Méneville, Megalohelcon Turner and Cercobarcon Tobias) are rediagnosed and the species are revised and redescribed. Rhamphobarcon Tobias is synonymized with Megalohelcon Turner, R.mosaicus Tobias is synonymized with M.torresensis Turner, M.uptoni Tobias is synonymized with M.ichneumonoides Tobias, and four species are newly described: M.mouldsi, C.bilobatus, C.grossi and C.niger. Relationships within the subfamily are discussed, as are those of the Trachypetinae to other braconid subfamilies. Comments on the biology and distribution of species are provided, along with an illustrated key to genera and species.

The biology of Mesostoa kerri Austin & Wharton, amember of the endemic Australian subfamily Mesostoinae, was investigated inthe laboratory and at the only known field site at Reedy Creek, SouthAustralia, where it causes stem galls onBanksia marginata Cav. Galls vary in shape fromspherical to elongate, with larger elongate galls appearing to inhibit distalfoliage growth. Their internal structure is characterised by a large number ofchambers occupied by wasp larvae, a melanised cambial layer, and partialdisruption and proliferation of xylem tissue. Larvae were observed to feeddirectly on the walls of their chambers. There is a direct relationshipbetween the size of galls and number of resident wasps, with the largest gallscontaining up to 300 individuals. Total wasps dissected from galls had a sexratio close to 1 : 1, although the ratio varied among galls from strongly maleto strongly female biased. Females are sluggish in behaviour and have not beenobserved to fly. They oviposit into preapical green stems and the pattern ofoviposition may determine the shape and size of the resultant gall. Male waspsemerge just prior to females and probably wait on galls for females to emergebefore mating. A number of factors, including the absence of early-stage gallsand substantial foliage growth distal to some galls inSeptember–October, indicates that M. kerri has anannual life cycle. Other gall residents occurred in 57% of sampledgalls, and included 11 species of Hymenoptera, 3 of Coleoptera and 1 ofLepidoptera. Data available for other Mesostoinae suggest thatBanksia is the exclusive host group and all species aregall formers.