American foulbrood and African honey bees (Hymenoptera: Apidae)

Abstract

We have taken samples of honey from individual beekeepers (N = 64), and of domestic (N = 35) and imported honey (N = 15) retailed in supermarkets in several sub-Saharan countries and cultivated these samples for Paenibacillus larvae subsp. larvae Heyndrickx et al. causing American foulbrood in honey bee colonies. The results are compared with samples of similar backgrounds and treated the same way but collected in Sweden (N = 35). No P. larvae subsp. larvae spores were found in any honey produced in Africa south of the Sahara although honey imported into this region frequently contains the pathogen. Swedish honey frequently contains P. larvae subsp. larvae spores although the general level of visibly infected bee colonies is low (roughly 0.5%). The results suggest that large parts of Africa may be free from American foulbrood. Behavioral studies (hygienic behavior) on Apis mellifera subsp. scutellata Lepeletier in Zimbabwe suggest that hygienic behavior of African bees could influence the apparent low level, or even absence of American foulbrood in large parts of Africa.