Eleven species of Acacia examined near Melbourne all suffered seed predation by larvae of weevils (Melanterius spp.). The life history of M. acaciae on A. baileyana is outlined. The weevils are univoltine and oviposit in developing seeds. Parasitization of immature stages is low. Infestation levels between individual trees, between host species and between years are very variable, but generally lower than levels recorded for seed predation on acacias elsewhere. Features of Melanterius biology are briefly described in relation to seed predators studied elsewhere.