Occurrence of two serologically distinct groups within Bacillus thuringiensis serotype 3 ab var. kurstaki

Abstract

Two groups distinguishable on the basis of crystal serology have been identified within Bacillus thuringiensis var kurstaki (serotype 3 ab). The toxicities of these two groups to Trichoplusia ni and Heliothis virescens expressed as T H ratio also differed. It is suggested that serotype 3 ab be separated into two subgroups designated as K-1 and K-73.