RNAi-based acaricides: On the Path to commercialization of new tools for mite management in crops and hives

Mites cause significant agricultural losses by feeding directly on crops and indirectly by reducing pollination services due to the negative impacts of honey bee parasites on apiary health. Further, mites are notorious for developing resistance to chemical control methods, creating an urgent need for new mode of action acaricides to be used in integrated pest management programs. Over the past decade, significant efforts to develop RNAi-based acaricides for agriculturally important herbivorous and parasitic mites have led to translation of basic research, representing potentially new solutions for growers and beekeepers. The availability of high-quality genome data has enabled the identification of mite gene target sequences sensitive to RNAi that limit impacts on beneficial organisms. Detailed studies of RNAi processes in mites have informed the development of practical methods for controlling mites in the field. Recent development of low-cost, large-scale dsRNA production, once a significant barrier to sprayable RNA products, has provided a springboard to advance RNAi miticides into commercial development. Here we review progress made to date in developing RNAi-based acaricides as new mode of action tools for controlling agriculturally important spider mites and the bee parasite Varroa destructor.