RESISTANCE TO AMERICAN FOULBROOD IN HONEY BEES .10. COMPARATIVE MORTALITY OF QUEEN WORKER AND DRONE LARVAE

Queen, worker, and drone honey-bee (Apis mellifera) larvae of similar ages and genotypes were given, in their food, a constant dosage of water-suspended Bacillus larvae spores, or water only, in 10 experimental replications. Pooled data from all replications showed that spore treatment resulted in about 93% mortality of female larvae reared as queens, 82% mortality of those reared as workers, and 68% mortality of the male (drone) larvae. Control treatment mortality was less than 5% for each caste. Chi square analyses of mortality associated with control treatments showed no significant differences between any two of the three castes, whereas mortality differences between castes following spore treatments were highly significant and are interpreted as resulting from differences in resistance. These differences in resistance are attributed to differences in food supplied by adult bees to the larvae. © 1969.