Abstract
An increasing number of studies show that urbanized areas are habitats of high biological value and ecological significance. Most bee species live in areas altered by man, either in cities - fragmented urban habitats - or in large rural monocultures. Our research is based on three-year observations of population development of the solitary bee Osmia rufa L. in three habitat types: city, suburbs and villages. We compared reproductive parameters and diversity of accompanying nest fauna. Population growth rate was high in all habitats, exceeding five times the number of cocoons placed in the previous year. We found no significant differences in the number of cocoons and brood mortality between areas with different urbanization levels. In nests located in suburbs, parasites and cleptoparasites occupied almost three times more nest chambers than in other habitats. Changes in the habitat structure had a significant impact on the diversity and abundance of accompanying fauna. Our study shows that red mason bees are flexible and easily adapt to new conditions, despite changes caused by urbanization and agriculture.