Effectiveness of purified Bacillus thuringiensis Berliner insecticidal proteins in controlling three insect pests of Australian eucalypt plantations

First instars of chrysomelid leaf beetles Chrysophtharta bimaculata (Oliver) (Coleopter: Chrysomelidae) and C. agricola (Chapuis) (Coleoptera: Chrysomelidae) were fed eucalypt leaves coated with purified protein encoded by the cryIIIA gene of Bacillus thuringiensis Berline variety tenebrionis. The CryIIIA protein was highly effective against C. bimaculata when presented on adult Eucalyptus nitens (Deane & Maiden) Maiden leaves, but not when leaves of the preferred host E. regnans F. Muell. were used. The difference between tree species may be the result of differences in the amount of endotoxin ingested or to interactions between the cryIIIA protein and eucalypt allelochemicals, (e.g., leaf oils). CryIIIA was not effective against C. agricola fed on juvenile E. nitens leaves coated with cryIIIA protein. We also tested purified protein encoded by the cryIa(b) gene of B. thuringiensis variety kurstaki in laboratory feeding trials against 1st instars of Mnesampela privata (Guene) (Lepidoptera: Geometridae). The CryIA(b) protein was highly effective against M. privata when presented on juvenile E. nitens leaves. These results indicate that CryIIIA and CryIA(b) proteins could be used to control 1st instars of C. bimaculata and M. privata, respectively, in some commercial eucalypt plantations when either sprayed as microbial formulations or present in transgenic plants.