Control of American Foulbrood by the Shaking Method

In a Danish apiary 15 bee colonies were fed honey containing 1.0×10 P. l. larvae spores and examined for two beekeeping seasons. 43 days after the spore feeding, 12 of the colonies showed clinical symptoms of American foulbrood (AFB). Only these 12 colonies were then treated with the shaking method. After the shaking method was carried out a major reduction in the number of spores in the honey of the treated colonies was seen. The number of spores were reduced to a level at which they did not provoke further clinical symptoms of AFB. Even though all colonies were fed the same number of spores 20% of the colonies never showed clinical symptoms. These colonies were able to reduce the number of spores in the honey within one season to a level that was equal to the treated colonies. In Denmark, the shaking method has been used successfully for the past 90 years.