[Changes in the number of deer louse-flies Lipoptena cervi (Hippoboscidae) in the forests of northwestern Russia].

Long term observations of the abundance fluctuations of the deer louse-fly Lipoptena cervi were carried out in forest areas of the Leningrad, Novgorod and Pskov provinces in 1988-1995. The registration of the winged individuals was held in the period of the mass flight in August by the number of deer louse-flies attacking a collector man during 1 km of the pathway. The abundance of deer louse-flies was being high everywhere up to 1993, while it decreased by 8-29 times in 1994-1995. The reason of the abundance decrease of deer louse-flies is the abrupt abundance decrease of the main host, the elk Alces alces.