SUMMARY
The present three-year study traces the diversity of four bee communities in fragmented pedemontane areas of Volcano Etna (Catania province, Sicily) near the Metropolitan City of Catania, under different land management regimes. The selected areas comprise two different urban parks within Catania (Parco Gioeni and Parco degli Ulivi), a Nature Reserve (Complesso Immacolatelle e Micio Conti, San Gregorio di Catania), and an agroecosystem (a citrus orchard, Aci Catena). Previous data obtained from a well-investigated area (Leucatia, north of Catania) have been used as a control for bee diversity for this study. The results include an outline of bee species richness, data on the composition of bee communities, and seasonal patterns, using several diversity indexes. The study of bee diversity shows a total of 163 species, arranged in five families. The four investigated locations include 104 species arranged in four families: Andrenidae (20 species), Halictidae (15 species), Megachilidae (31 species), and Apidae (38 species); with a similar number of species (102) recorded in the control site (Leucatia). The study highlights strong seasonal variations of bee communities in all investigated sites, with differentiated seasonal patterns, whose compositions are affected mainly by forage sources, suitable nesting sites, as well as human activities. The data obtained provide a rough but basilar framework to assess management strategies to maintain adequate levels of bee diversity, especially for those areas with moderate to high environmental fragmentation. Our findings highlight the importance of season-long sampling of bee population factors if used as indicators in ecological studies.