EN
Bats have a set of features that make them very effective insects predators, thus they can potentially play an important role as a biological pest control agent in forests. The active flight ability, nocturnal lifestyle, high level of metabolism and a lack of a significant threat from predators make bats the most important predators of insects active in the evening and at night. All bats species noted in Poland are associated with forests, where they use various microhabitats and forage on various types of prey. According to foraging strategy and diet, insect−eating bats have been divided into several ecomorphological groups, which shows different efficacy in foraging on particular species of forest insects pests. Numerous studies indicate that bats diet includes primary forest pests from order Lepidoptera and also some species from Diptera and Coleoptera. Forest pests from Lepidoptera and Diptera represent a significant share in the diet of gleaning bats, especially long eared bats Plecotus sp., barbastelle Barbastella barbastellus and Natterer’s bats Myotis nattererii. During the swarming period Melolonthinae sp. and Amphimallon sp. (Coleoptera) dominate in the diet of all larger species of bats, especially aerial hawkers and bats foraging along the linear elements in the landscape: serotine bat Eptesicus serotinus, commone noctule Nyctalus noctula, lesser noctule Nyctalus leisleri and mouse eared bat Myotis myotis (which forage mainly on ground beetles). Moreover many bat species are able to change diet and adapt it to the most abundant prey. According to forest protection, the most important guilds are gleaners, bats foraging in the dense vegetation and canopy and aerial hawkers. Bats have a great potential as a biological control agents and all conservation practices including this group of animals will simultaneously support the natural forest resistance mechanisms.