Bioassay for grooming effectiveness towards Varroa destructor mites in Africanized and Carniolan honey bees

Abstract

Grooming behavior is considered a varroosis tolerance factor of Africanized honey bees, but this behavior is difficult to evaluate directly within the honey bee colony. A laboratory bioassay was developed to measure the intensity and effectiveness of grooming responses by worker bees artificially infested with one Varroa mite. At a study site in tropical Brazil, the sequence of seven well-defined grooming reactions towards mites of different colonial origin was compared. In a total of 226 assays, Africanized bees responded significantly faster and more intensively than Carniolan workers. But there were no statistical differences in the removal of mites according to the bee types. Even extensive grooming behavior never resulted in damage or death of the mites. The possible use of the bioassay as a screening for the extent of the grooming behavior is discussed.