Seventy strains of B. asteroides isolated from the honey bees Apis mellifera and A. cerana raised in 15 different countries, 73 strains of B. indicum from Apis dorsata and A. cerana from The Philippines and 28 strains of B. globosum isolated from feces of various animals and sewage, were studied for the existence of related structures among their plasmid complements with the Southern blot-hybridization technique. Thirteen different structures were found in B. asteroides and three in B. indicum and B. globosum. A total of twenty five strains were used as source of probes in the hybridization experiments.