Bees from Southern Brazil: diversity, floral visitation, and conservation

ABSTRACT Understanding bee diversity and their relationships with plants is crucial for conserving pollination services. Here, we focused on the southern region of Brazil to: i) provide an overview of bee diversity based on fauna inventories, ii) compile studies on floral visitation in natural and agricultural systems, and iii) discuss the threats and conservation status of bee fauna, particularly through endangered species lists., we conducted a systematic review of the literature, and retrieved 138 papers. Among the 68 systematic bee inventories, most were carried out in Paraná, followed by Santa Catarina and Rio Grande do Sul. Studies indicate bee richness up to 400 species at regional scale (multiple localities). Of the total visitation studies, 48 involved cultivated plants, while 22 were focused on non-cultivated species. Canola was the most researched among the 16 species of cultivated plants, appearing in nine papers, followed by soybean with eight articles. In the case of non-cultivated plants, a total of 23 plant species were studied, with Bromeliaceae and Orchidaceae as the most common families. We identified a need for increased research efforts in the western regions of the Atlantic Forest, as well as in the Cerrado and Pampa biomes based on the scarcity of initiatives in these areas. There is a significant gap in our knowledge regarding the pollination of neglected crops and native plants. Regarding bee conservation, comprehensive monitoring and data collection efforts are urgently needed to assess the status of bee populations and identify areas where conservation actions are most critical.