The Ecology of Serotype 4B of Bacillus thuringiensis

Summary Twentyfive separate isolates of serotype 4B of the aerobic sporeforming insect pathogen, Bacillus thuringiensis , have been obtained over the period 1961–68. Most of the isolates of this particular serotype were obtained from storage products insects infesting such places as grain stores, flour mills or ships carrying grain materials. In one instance the organism was isolated from insects infesting Guinea corn growing in the field. In comparison with the other serotypes of this bacillus the association with stored products environments is striking and, on several occasions, it has been possible to trace the distribution of the bacteria by movements of infested materials from one part of the world to another.