Activity of Proteins from Two New Zealand Strains of Bacillus thuringiensis against Larvae of Antitrogus consanguineus (Blackburn) (Coleoptera: Scarabaeidae)

The activity of proteins from two New Zealand strains of Bacillus thuringiensis, DSIR517 and DSIRl246, was determined against the Australian canegrub Antitrogus consanguineus. Two DIG‐labelled crystal proteins from strain DSIR1246 and three from strain DSIR517 bound to the brush border membrane vesicles of third‐instar A. consanguineus. However, when fed to second and third instars the proteins caused no reduction in weight gain or no increased mortality. We conclude that the proteins are dissolved and activated in the gut of A. consanguineus and bind to the gut wall and that the proteins presumably do not insert into the plasma membrane of the gut of A. consanguineus resulting in no toxicity.