Electrotarsogram responses to synthetic odorants by Varroa destructor, a primary parasite of western honey bees (Apis mellifera)

Olfaction is a key sensory modality for many arthropods and could be used as a tool in pest management through manipulation of pest behavior. Management ofVarroa destructor, important parasitic mites of honey bees, could be improved through better understanding of the chemical ecology of this host-parasite relationship. We refined techniques of mounting mites to obtain electrophysiological recordings (electrotarsograms) of their responses to synthetic odor stimuli. Results of 271 electrotarsogram recordings fromV. destructorrevealed responses to 10 odorants relative to solvent controls. Electrotarsogram responses to methyl palmitate, ethyl palmitate, and 2-heptanol were highest at the lowest stimulus loading (10 ng) we tested, suggesting thatV. destructormay have acute sensitivity to low concentrations of some odors. Results suggest that odorant origin (e.g., methyl oleate from honey bee larvae, geraniol from adult honey bee alarm pheromone, and alpha-terpineol, a plant secondary metabolite) can influence the degree of electrophysiological response.Varroa destructortended to be more responsive to known attractants and repellents relative to previously unexplored odorants and some repellent terpenes. Electrotarsograms offer the potential for screening odors to determine their importance inV. destructorhost detection.