Effective biotechnical control of varroa: applying knowledge on brood cellinvasion to trap honey bee parasites in drone brood

Biotechnical methods of varroa (Varroa jacobsoni) control are based on the idea that mites inside brood cells are trapped and can then easily be remov ed from a honey bee (Apis mellifera) colony. Trapping is most efficient usi ng drone brood in otherwise broodless colonies. In theory, one trap-comb wi th drone brood is enough to achieve control. We designed and tested two met hods using trap-combs with drone brood. In the first experiment, effectiven ess of the control method varied considerably, from 67% to 96%. However, th e observed effectiveness in each separate colony was similar to the predict ion based on knowledge of behaviour of mites invading brood cells. Effectiv eness depended on the number of drone cells that had been available for mit e trapping. In the second experiment, we adjusted the method to improve pro duction of trap-combs with drone brood, since this appeared to be crucial f or trapping efficiency. The observed effectiveness of 93.4% demonstrates th at trap-combs with drone brood can effectively trap mites, thereby offering a non-chemical method of varroa control. The use of knowledge on invasion behaviour of mites for evaluating trap-comb methods and modelling varroa po pulation dynamics is discussed.