The population dynamics of the mite Va/Toa jacobsolli Oudemans were studied in summer in colonies of honeybees (Apis mellifera cecropia) in the region of Thessaloniki, Greece. The reproductive rate of the mite was estimated by examining the progeny of 364 females in worker cells and 131 in drone cells containing pupae with dark eyes and light brown thorax (i.e. 9 days after the worker cells and 10 days after the drone cells were sealed). The proportions of non-egg laying mites on the 2 kinds of brood were about 19% and 4% respectively. The reproductive rate was 2'92 for mites in worker cells and 3'66 for mites in drone cells. The rate for females reaching adulthood from each original female mite, for a single passage through the brood cells, was 0'71 for worker and 1'70 for drone brood.