Population dynamics of ectoparasitic bee-mite (Tropilaelaps clareae) in European honey bee (Apis mellifera) colonies in north-western India

Studies on year round population fluctuation of Tropilaelaps clareae Delfinado and Baker in Apis mellifera Linnaeus colonies through different seasons under with two strength colonies (8-10 and 18-20 bee frame strength) in north-western India revealed the maximum mite population during March-April that synchronized with the peak worker brood rearing in the bee colonies. The maximum mite population on adult bees and mite fall were also observed in March-April but the population of the mite on adult bees was very small. This showed that this mite has negligible phoretic behaviour. This is in contrast to Varroa destructor Delfinado and Baker which showed a strong phoretic behaviour. The mite population in worker brood was positively correlated with worker brood rearing in 8-10 and 18-20 bee frame strength A. mellifera colonies (r = 0.74, r = 0.79, respectively). Since the residual mite population starts multiplying quickly to increase in brood rearing with the spring onset, the strategy of reducing its carry over to spring brood rearing period by hitting it with some effective management measures before the spring onset when mite population is low, could be a promising strategy. Further, in double strength (18-20) honey bee colonies wherein brood rearing had been higher than in low strength (8-10) honey bee colonies, the mite population had been the lowest in the brood in the former colonies which could be attributed to high adult nurse worker bee population resulted in a more mite fall which resulted in lower incidence of the mite in the brood. Thus, it can be inferred that honey bee colonies must be maintained stronger to take these to at least one super.