Ixodes, persulcatus, I. ricinus, D. reticulatus, D. marginatus, H. concinna were recorded in different regional environmental regions. The northern districts of the region are endemic for tick-borne encephalitis (TBE) and Ixodes tick-borne borreliosis (ITBB). The infection of ticks with TBE virus is 0.25%, that with Borrelia is 10.3% of the total number of the examinees. In 1997 TBE and TTBB morbidity rates were 1.91 and 2.0 per 100,000, respectively. Data on the phenology of prevailing Anopheles messeae are given. Human malaria contamination may take 99-102 days (the first ten days of June to the second ten days of September). The large size of malaria mosquitoes and the presence of imported cases of malaria make it possible to deteriorate the malaria epidemiological situation. The larvicidal activity of a preparation derived from shepherd's-purse (Capsella bursa pastoris) [correction of caseweed (Bursae pastoris)] was tested. 80-85% deaths of larvae of second-third ages occurred 48 hours after treatment with the preparation, 1 kg/ha.