Abstract
Honey bee, Apis mellifera L., hygienic behavior is the uncapping and removing of brood killed by American foulbrood. The magnitude of removing behavior was significantly correlated with colony resistance to chalkbrood, Ascosphaera apis, after infection by feeding spores to the colonies. Uncapping behavior, however, was not significantly correlated with colony resistance. Hygienic behavior confers resistance to both a bacterial and a fungal brood disease. Colonies at the same apiary had different susceptibilities to infection. This suggests that resistance to chalkbrood is complex and involves other mechanisms besides hygienic behavior.