A direct assay to assess self-grooming behavior in honey bees (Apis mellifera L.)

Grooming behavior confers resistance to honey bees against the mite Varroa destructor and thus is a mechanism of interest for studies of social immunity and breeding purposes. However, mites are not always available to conduct grooming assays and can introduce variability to the evaluations. Therefore, the objective of this study was to evaluate the use of wheat flour as an irritant in a laboratory assay to assess self-grooming behavior in honey bees. Presumed Varroa-susceptible and Varroa-resistant genotypes were used to determine the time it took the bees to initiate grooming instances and the proportion of bees that responded when exposed to either flour or a Varroa mite. Flour elicited significantly faster grooming responses and with a higher proportion of individuals in both genotypes in comparison with V. destructor. Also, significant differences between both genotypes were observed. It is concluded that flour can be used as an irritant instead of V. destructor to evaluate self-grooming behavior in bees in the laboratory.