Shook Swarm and OTC Antibiotics for European Foulbrood Control

Research Summary

Waite, R. J., Brown, M. A., Thompson, H. M., Bew, M. H. (2003). Controlling European foulbrood with the shook swarm method and oxytetracycline in the UK. Apidologie 34: 569-575.

Web Link:Controlling European foulbrood with the shook swarm method and oxytetracycline in the UK.

Brief Description:
In the United Kingdom, where this study occurred, European foulbrood (EFB) is a regulated disease. Typically, infected colonies can be treated with the antibiotic oxytetracycline (OTC), if the colony is determined to be able to respond to treatment. When the infection is severe, the colony is destroyed. The objective of this study was to determine if the shook swarm method combined with the antibiotic, OTC could be as effective at controlling the disease as OTC treatment alone.

The tested method involves shaking all the bees off the combs in EFB infected hives. The queen is caged separately and released with the workers later. The shaken bees are put on new or contaminate free equipment and foundation. The contaminated combs were destroyed. Once on new equipment, the bees were fed sugar syrup containing the antibiotic, OTC. The method to do this was to fill a 250 ml jar with 1kg table sugar and 568 ml of water. 1g of OTC (active ingredient) was added to the syrup. This was then sprinkled into cells on empty frames next to the brood nest, avoiding open brood. The concentrated solution will kill open brood, but should not cause problems once diluted by worker bees. Eight weeks later, the colonies were inspected for clinical signs of disease. Control colonies were fed OTC the same way, but the shook swarm method was not used.

During the season after treatment, most colonies responded well to both the control and shook swarm methods. Some colonies died that season, or became reinfected, but both methods seemed overall effective. The following season however showed different results. Control colonies treated with OTC alone became reinfected at the level of 21.1%. Colonies treated with OTC and the shook swarm method became reinfected only about at 4.8%. However, 4 of the shook swarm colonies died while only 2 of the control colonies died. The total number of colonies in the trial was 50.

The authors suggest that this is a promising method to control EFB and was well received by the beekeepers in the study. (Reviewer’s note: Other studies describe the problem of recurrence of EFB in subsequent years. Methods to reduce recurrence are likely to be important in problematic EFB areas.) The authors point out that American foulbrood control has not been as successful with this method. This study only suggests this method is successful for the control of EFB.

summary/review by Michael Wilson, University of Tennessee