Long-term changes in the species composition and distribution of Bombini (Apidae) in Cracow since the mid 1850s

Current distribution of bumblebee species in Cracow was studied in 2000-2003 in 23 atlas squares. The results were compared with historical data available for last 150 years, including published materials and museum collections. A total 28 bumblebee species were recorded throughout that period. Among them, 11 species are currently threatened in the study area. There were stated three tendencies among the studied bumblebee species. After 1850, 10 species were strongly regressing (withdrew from the Cracow area altogether or range contraction); further 11 species were more or less stable in their area; the next 6 species were strongly expanding in Cracow. 6 species were stated as a new for Cracow, including 2 species recorded between 1901-1972 and 4 between 1973-2003. Negative population tendencies by the Bombini in the Cracow area were the result of both natural and anthropogenic factors. Species protection and conservation of the most valuable areas as nature reserves are expected to prevent further decrease of bumblebees in the Cracow area.