In Silico Analysis of Potential Off-Target Effects of a Next-Generation dsRNA Acaricide for Varroa Mites (Varroa destructor) and Lack of Effect on a Bee-Associated Arthropod

We examined potential off-target effects of a novel double-stranded RNA (dsRNA) biopesticide to control varroa mites within honey beehives. The potential exposure of non-target species within beehives calls for comprehensive evaluation. We employed a two-fold approach. First, via bioinformatics analysis, we assessed potential gene silencing effects on arthropods associated with beehives and arthropods of conservation concern. Second, we conducted dsRNA feeding trials on a common beehive-associated species, the greater wax moth (Galleria mellonella), to corroborate that no hits in the bioinformatics analyses indeed meant no dsRNA activity in vivo. Our findings indicate minimal impact on wax moths following continuous dsRNA dietary exposure, in line with the bioinformatics findings of no perfect matching siRNA hits. Our results are indicative that this dsRNA biopesticide appears highly varroa-specific and likely has fewer non-target effects compared to many of the currently available varroa control methods based on synthetic chemicals.