The bees of dark forest species (Apis mellifera mellifera L.) are winter-hardy. These bees are able to effectively use a short honey harvest. Introgression of southern bee species in the Russia affects ro the economic quality of local northern species of bees. Introgression of species reduces their immunity, thereby It was enhancing susceptibility bees to infection with ectoparasites, as well as distribution of various viral diseases. Varroa destructor mite infestations on bees may predispose to infection by viruses.