A Synopsis of Important Pests and Diseases in Australian Forests and Forest Nurseries

Abstract

SUMMARY Major primary defoliators in commercial eucalypt forests are the beetle Chrysophtharta bimaculata, the phasmatids Didymuria violescens and Podacanthus wilkinsoni, and the moths Perthida glyphopa and Uraba lugens. The foliage of young eucalypts on grassy sites is attacked by a range of insects including species of the beetle genera Anoplognathus, Chrysophtharta and Heteronyx. Several ambrosia beetles degrade the wood of many eucalypts. The termites Coptotermes acinaciformis, C. frenchi and Porotermes adamsoni are the major wood destroying pests. Dieback and tree mortality of eucalypts is sometimes associated with the root pathogens Armillaria spp. in southern Australia, and Phytophthora cinnamomi in both Western Australia and the south-eastern States. Phytophthora cinnamomi has also killed exotics in some forest nurseries as far north as Queensland. Under certain conditions, Diplodia pinea produces shoot dieback and sometimes defoliates radiata pine. Native conifers in south-eastern Queensland are damaged by at least three species of coleoptera and four species of fungal pathogens. Plantations of exotics have generally remained healthy. However, the bark beetle Ips grandicollis and the wood wasp Sirex noctilio, associated with the pathogen Amylostereum areolatum, are now established in pine, and the pathogens Melampsora spp. and Swiss needle cast Phaeocryptopus gaeumannii have recently been found on poplar and Douglas fir respectively. This suggests that exotics can eventually be susceptible to introduced destructive biological agencies on favourable sites.