[Use of original plant communities as indicators for the occurrence of common ticks].

In an investigation conducted in the South and West Bohemian region the author paid attention to the incidence of the tick Ixodes ricinus and foci of tick-borne encephalitis in original plant communities. In Southern Bohemia in places of original communities of acidophil oak forests, oak-hornbeam woods and their mosaic combinations as well as combinations of flowers and beech forests and meadows and alder trees the author detected 93.5% of the breeding places of ticks. In Western Bohemia in original oak forests there were 97.2% breeding places of Ixodes ricinus. In other original plant communities, although influenced and partly altered by human activities--i.e. in highly located beech woods and pine tree woods and in damp communities--in peatbogs, meadows and grassland no ticks were found. Evaluation of a territory, based on plant and animal communities and typical species as their indicators, is a useful method as regards the prognosis of the prevalence of ticks or possibly foci of tick-borne encephalitis, as was demonstrated on the example of an uncommon focus of tick-borne encephalitis and tick-borne borreliosis on the upper Vltava river.