Phenology of wild and honey bees (Hymenoptera: Apoidea) in the Sudanian Savannas of West Africa

Wild and honey bees in West Africa are very crucial for plant pollination and ecosystem functioning. However, the study on the phenology of bee species in this region is poorly documented, jeopardizing their conservation. The current study was carried out in three localities across two climatic zones in Southern Burkina Faso. During one-year fieldwork, 19,022 specimens of bees were captured using colored pan traps (UV: white, blue and yellow). Bees were identified at the species level in the Royal Belgian Institute of Natural Sciences. A total of 105 bee species belonging to 32 genera and 4 families (Apidae, Megachilidae, Halictidae and Colletidae) were identified. Halictidae was the most diverse family. The diversity of bee species varied between land-use intensity and climatic zones. The highest diversity was found in low-disturbed zone (H’ = 2.73) and in the most humid zone. The lowest richness of bees (17 species) was recorded in January corresponding to the coolest period, while the highest richness was obtained in August (62 species). The high abundance of bee species was recorded during the wettest months (July and August) whereas lower abundance was observed in the dry season (October). According to the phenology diagrams, seven wild bee species Braunsapis sp. 1, Braunsapis sp. 2, Braunsapis sp. 3, Ceratina sp. 1, Hypotrigona gribodoi, Pseudapis interstitinervis, Seladonia jucunda and the honeybee Apis mellifera were present throughout the year. The other bee species were encountered at different periods of the year. The knowledge of bee phenology constitutes an important database for bee monitoring and bee conservation and their ecosystem services that they provide free to humans.