Varroa resistance in Apis cerana: a review

Varroa is a major world-wide pest to Western honey bees (Apis mellifera), causing huge ongoing losses of colonies every year. Conversely, the Eastern honey bee (Apis cerana) is less vulnerable to the mite having existed alongside it over a long evolutionary period. Research conducted during the 1980s and 1990s, shortly after Varroa had spread across the globe, concluded that the Eastern honey bee was less vulnerable because it displayed higher levels of grooming behaviour, brood removal behaviour and mite infertility than its Western counterpart. However, this review on these Varroa resistance traits in A. cerana indicates that there is surprisingly little evidence for these conclusions. This review explores this evidence and discusses the potential flaws in the studies and the gaps that still remain in our knowledge of Varroa resistance traits in A. cerana.