An Effect of Bacillus sotto on the Larvae of Bombyx mori

Abstract

The paralysis of silkworm larvae (Bombyx mori L.) caused by Bacillus sotto Ishiwata and the extraction of a toxic protein from cultures of this microorganism have been reported elsewhere (1, 2, 3). In preliminary studies of the mode of action, changes have been noted in the pH of the blood of affected larvae.Fourth- and fifth-instar larvae were fed foliage coated with B. sotto toxin and at intervals the blood pH was determined as described by Heimpel (4). Control larvae, reared from the same egg mass, were fed untreated foliage.