1. Department of Zoology, Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic; e-mail: , honza@riegert.cz
2. Nature Conservation Agency of the Czech Republic, Praha 11 – Chodov, Czech Republic, e-mail: , jan.vrba@nature.cz
3. Department of the Environment, Agriculture and Forestry, Regional Office of the South Bohemian Region, České Budějovice, Czech Republic; e-mail: