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Chrysophtharta bimaculata is a serious pest of eucalypt forests in Tasmania. The beetle overwinters as a diapausing adult, but it is poorly documented whether it forms overwintering aggregations or where it shelters. During winter 1992, we searched 386 possible overwintering sites for C. bimaculata in Eucalyptus obliqua forests. Fourteen types of habitat were identi®ed, of which clumps of Gahnia grandis sheltered the greatest mean number of insects (3.31 0.72 insects/plant, n 65 plants), while bracken fern litter sheltered the least (0.14 0.14 insects/sample, n 7, 1 m 2 quadrat samples). Of the 14 habitat types, all except two (under the bark of eucalypt stags and in G. grandis clumps) were more often unoccupied. Beetles were more commonly found on mature forest edges or in logged and regenerating forests; few were found within mature forests. Our results show that C. bimaculata rarely forms overwintering aggregations of greater than 20 individuals per site, nor does it appear to have a signi®cant pre-diapause dispersal.

Despite considerable efforts the eucalyptus tortoise beetle Paropsis charybdis continues to defoliate Eucalyptus nitens plantations throughout New Zealand preventing expansion of this forest resource or requiring constant management through aerial insecticide application A parasitoid wasp of the springtime larval stage of the eucalyptus leaf beetle Paropsisterna agricola (Chapuis) (Chrysomelidae) in Tasmania is being investigated as a potential biological control agent for New Zealand The potential agent Eadya paropsidis Huddleston and Short (Braconidae) was caught as adults on the wing from E nitens plantations in northern Tasmania and brought into the laboratory in Hobart for preliminary host specificity testing Using a sequential nochoice test method to examine the response of individual females 9 of the 10 female parasitoids attacked P agricola while 7 of those 9 attacked P charybdis larvae Those P charybdis larvae that were attacked proved to be a highly suitable physiological host for E paropsidis development emerging as a larger sized parasitoid larva from P charybdis than from P agricola This potential agent will be further evaluated in a collaborative project with New Zealand eucalyptus growers and the Sustainable Farming Fund