Biocontrol agents of varroa destructor, honeybee (Apis mellifera) parasite

Abstract

The honeybee (Apis mellifera) is highly susceptible to the Varroa destructor mite. The unprotected colonies typically collapse after one to three years, usually. A chemical protection is inconsistent due to the mite’s resistance and pose a toxicological threat because of residues in bee products. This review aimed to investigate the advantages and disadvantages of biological agents for the Varroa control. We have elaborated the importance and biological aspects of the mite’s interaction with the bee as a host and with the potential bioagents. The impact of physical conditions in a colony on the bioagents’ efficacy has been discussed. During the last two decades, the beneficial arthropods, entomopathogenic nematodes, entomopathogenic fungi and bacteria have been studied for their acaricidal activity against the Varroa or similar organisms. The entomopathogenic fungi of the genera Metarhizium and Beauveria, the entomopathogenic bacteria Bacillus thuringiensis, and the symbiotic bacteria of entomopathogenic nematodes are recognized as the potential bioagents due to their high efficiency against the Varroa and due to their provision of safety for the bees. In the future studies, the bioassay standards for a testing of the Varroa bioagents’ should be developed. The biotechnological enhancements of potential bioagents are necessary to increase their tolerance to the physical conditions in a beehive and to maintain the bees’ and beekeeper’s safety and honey quality.