Canadian Forest Service Publications
Mode d'action de Bacillus thuringiensis chez Choristoneura fumiferana (Lepidoptera : Tortricidae) : importance des spores. 1979. Smirnoff, W.A.; Valéro, J.R. The Canadian Entomologist 111 : 305-308.
Issued by: Laurentian Forestry Centre
Catalog ID: 16276
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Results of previous research revealed that the effect of Bacillus thuringiensis on spruce budworm was a septicemia enterotoxicosis dependent on the ability of spores to penetrate to the insect hemolymph. Some scientists still maintain that the rolde of B. thuringiensis crystals (endotoxin) is primordial and is by itself responsible, by toxemia, for mortality in Choristoneura fumiferana. Consequently, new studies were undertaken to confirm the role of spores in B. thuringiensis infection of this insect. Infection tests were carried out with normal, irradiated, acrystalliferous and non-sporogenous strains, of B. thuringiensis, with purified and semi-purified crystals, with pure spore preparations of B. thuringiensis and with enomopathogenic Bacillus cereus. The results of these tests revealed that acrystalliferous strains of B. thuringiensis and B. cereus infected larvae of C. fumiferana more successfully than purified or semi-purified crystals.