GEOMETRIC APPROXIMATION OF THE INFESTATION OF HONEY-BEE BROOD CELLS BY VARROA-JACOBSONI AND IMPLICATIONS FOR THE ESTIMATION OF BROOD INFESTATION, FOR POPULATION-MODELS AND FOR THE PROPORTION OF NON-SIBLING MATINGS

The parasitic mite Varroa jacobsoni infests the brood cells of its hos t Apis mellifera and reproduces in them. The distribution of the mites in the brood cells is an important aspect of the parasite's biology, with implications for the estimation of the bee brood infestation and possible damage to the brood, for models of the dynamics of population growth, and for the degree of outbreeding. We describe a method for e stimating the distribution of varroa per cell, i.e. the percentages of brood cells with 0, 1, 2,... mites, by the geometric distribution. Th ree estimates are presented, each referring to a different sampling me thod. One is given in detail, the other two just mentioned. We found t hat the geometric distribution model is applicable to worker brood as well as the usually more highly infested drone brood, and results in a good fit of the natural distribution of varroa per cell. Based on thi s estimation, we provide a method to assess the degree of outbreeding by calculating the probabilities of non-sibling matings.