Moore, I.
Navon, A., Div. of Entomology, ARO, The Volcani Center, Bet Dagan, Israel

The effect of ten different laboratory strains of Bacillus thuringiensis and of the thermostable exotoxin, was tested on larvae of Spodoptera littoralis Boisduval. Endotoxin poisoning was not observed and whenever mortality rose substantially above the controls, it seemed due to the thermostable exotoxin and not to the parasporal crystal. Treatment of a commercial preparation with substances dissolving the crystal did not elicit acute toxemia, nor did abrasives administered with this preparation bring about fulminating septicemia. © 1973 Springer Science + Business Media B.V.