Grooming behavior and damaged mites (Varroa jacobsoni) in Apis cerana cerana and Apis mellifera ligusticaI. Friesa, Wei Huazhenb, Shi Weib and Chen Shu Jinb
a Department of Entomology, Swedish University of Agricultural Sciences, S-75007 Uppsala, Sweden
b Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Xiang Shan, Beijing 100093, China
Abstract - Varroa mite mortality and mite damage in colonies of Apis cerana cerana Fabr and Apis mellifera ligustica Spin, where mites were added to observation hive bees and to full-sized colonies of both bee species, were studied. The results show grooming behavior in A cerana but the results also indicate that this behavior may be less effective than previously recorded. In A mellifera colonies, phoretic mites were also removed by the bees but less effectively than in A cerana colonies. The proportion of experimentally-added live mites in the debris that were visibly damaged in colonies of A cerana was 30% (n = 115). From A mellifera colonies, 12.5% of the introduced mites had visible injuries caused by the bees (n = 65). The mites recovered from both bee species showed reduced survival rate on bee pupae compared to control mites. Compared to A mellifera, A cerana is more effective in both removing mites and causing mite damage. However, in A mellifera phoretic mites are also removed by the bees, and some of them are injured. Since no reproduction of Varroa mites occurs in worker brood in A cerana, extremely effective grooming behavior may not be needed to explain the tolerance of A cerana to Varroa mite infestations. The results presented demonstrate that more research is needed to evaluate the importance of grooming behavior to Varroa mite tolerance in both A cerana and A mellifera.
Key words: Apis mellifera / Apis cerana / grooming behavior / Varroa jacobsoni / tolerance