EustochomorphaGirault, with one described species,E. haeckeliGirault, from Australia is redescribed.NeotriadomerusHuber,gen. n., is described, together with seven new species, all from Australia:N. burwelliHuber,sp. n.,N. crassusHuber,sp. n.,N. darlingiHuber,sp. n.,N. gloriosusHuber,sp. n.,N. longiovipositorHuber,sp. n.,N. longissimusHuber,sp. n.(one of the largest species of Mymaridae), andN. poweraeHuber,sp. n.ProaresconHuber,gen. n., is described forP. primitivum(Huber),comb. n., transferred fromBorneomymarHuber, andP. similisHuber,sp. n., from Thailand. The previously unknown male ofBorneomymar madagascarHuber is described and the genus is redescribed from critical point dried and slide mounted specimens. Triadomerini,stat. n., is proposed to include six genera:Borneomymar,EustochomorphaandNeotriadomerus, and the CretaceousCarpenterianaYoshimoto,MacalpiniaYoshimoto andTriadomerusYoshimoto. Aresconini is proposed to include five (possibly six) genera:AresconEnock,KikikiHuber and Beardsley,ProaresconHuber andTinkerbellaHuber and Noyes, and the CretaceousMyanmymarHuber and, tentatively, alsoEnneagmusYoshimoto. The two tribes are proposed as being the earliest lineages in Mymaridae, withNeotriadomerusandTriadomerusbeing sister genera to the remaining extant and extinct genera, respectively.