Submitted to: Popular Publication
Publication Type: Popular Publication
Publication Acceptance Date: March 22, 2007
Publication Date: May 1, 2007
Citation: Meikle, W.G., Mercadier, G., Girod, V. 2007. Les micro-champignons, nouvel espoir dans la lutte biologique contre Varroa destructor. Popular Publication.
Interpretive Summary: Varroa mites are one of the most important pests of honeybees worldwide and beekeepers are very interested in new ways to treat varroa infestations without using chemicals that contaminate honey and wax. Biopesticides, which use pest diseases to control the pests, are one option, but many diseases of insects and mites are not very specific and might hurt the bees. We found a strain of fungus attacking varroa mites in a commercial apiary in France, and tested the fungus in lab experiments on varroa mites. Results showed that mites were very susceptible to the fungus. We then conducted small scale field experiments and the fungus caused the mites to drop out of the hive at higher rates than normal. We conducted a larger field experiment to see if the fungus hurt the bee colony by weighing the beehives and by monitoring the adult and larval bees and the honey stocks. We found no negative impact of fungus treatment on the bees at all, and we did find that the fungus caused more mites to fall than usual. Commercial and hobby beekeepers should benefit from a new, chemical-free way to kill varroa mites.
After almost twenty years, research on the chemical control of Varroa destructor has still not provided a final answer. This mite parasite is still a serious menace to colonies of Apis mellifera. Laboratory work has shown that several species of entomopathogenic fungi, which are found naturally in beehives, are virulent against varroa mites. Described below are results from the first two years of a study carried out by the European Biological Control Laboratory (EBCL), in collaboration with two beekeeping organizations in southern France, the Comité Technique et Sanitaire Apicole du Gard (CTSAG) and the Association de Développement de l'Apiculture Professionnelle en Languedoc-Rousillon (ADAPRO-LR).