Victoria Soroker
Marin Kovačić
Fani Hatjina
& Varroa Task Force Members
Varroa Challenge
Varroa destructor mites are parasites specific to honey bees Apis mellifera and A. ceranae and can be found both on adult bees and in cells where they feed and reproduce on developing brood. Varroa (Figure 1) began to parasitize colonies of Western honey bees, A. mellifera, in the mid-20th century. Despite all research and control efforts, it is still recognized as one of the major drivers of colony mortality today (Traynor et al., 2020). Even more damaging to bee health is the combination of Varroa and its vectored viruses (de Miranda & Genersch, 2010; Grozinger & Flenniken, 2019).
Over the years, a variety of mite control methods were developed and utilized, but none have proven fully satisfactory. Especially among large beekeeping operations, Varroa control often involves abundant use of synthetic acaricides. This approach is popular due to fast application and low labour costs, but intensive use of acaricides also has negative consequences on bees and their products. Acaricide residues reduce the quality of bee products.
Furthermore, these acaricides lead to the evolution of resistant mites (Mullin et al., 2010; Sammataro et al., 2005), while often weakening the bees due to synergistic effect with other agrochemicals (Simon-Delso et al., 2014). The current situation of Varroa control can be considered critical as, in many countries, just few synthetic chemicals remain effective against the mite. It has been widely recognized that honey bee stocks resistant to mites are an essential part of any sustainable long-term control program (Dietemann et al., 2012; Spivak & Gilliam, 1998) and it is obvious that the current situation necessitates the development of an integrated strategy for Varroa pest management. The big challenge is that the efficacy of Varroa control measures varies with local abiotic conditions, beekeeping practices and honey bee stocks.
