INFLUENCE OF RESISTANT HONEY-BEE HOSTS ON THE LIFE-HISTORY OF THE PARASITE ACARAPIS-WOODI

Non-infested, young adult honey bees (Apis mellifera L.) of two stocks were exposed to tracheal mites (Acarapis woodi (Rennie)) in infested colonies to determine how divergent levels of susceptibility in host b ees differentially affect components of the mite life history. Test be es were retrieved after exposure and dissected to determine whether re sistance is founded on the reduced success of gravid female (foundress ) mites to enter the host tracheae, on the suppressed reproduction by foundress mites once established in host tracheae or on both. Cohorts of 30-60 bees from each of ten resistant colonies and eight susceptibl e colonies were tested in eight trials (three to five colonies per sto ck per trial) having exposure durations of 4, 9 or 21 days. The princi pal results were that lower percentages of resistant bees than of susc eptible bees routinely became infested by foundress mites, individual infested susceptible bees often had more foundress mites than individu al infested resistant bees did and mite fecundity was similar in both host types. The infestation percentage results corresponded well with similar results from a prior field test of these stocks and, thus, sug gest that the bioassay is useful for assessing honey bee resistance to A. woodi.