Wild Bees: Diversity, Ecology, and Stressors of Non-Apis Bees

Bees comprise a large group of over 20 000 species that show a wide range of forms, habits, plant associations, and degree of social interactions. The steep decline in managed honey bee colonies in North America and Europe since the mid 2000s has precipitated a big investment on developing a better understanding of the diversity of life history traits among the non-Apis bees, their role in pollination services and how these species are responding to the rapid and multiple facets of environmental change. Here, I provide an overview of the evolutionary history of bees (where do they come from), their diversity (how many species and lineages), and their variation in social behavior and life cycles. Then, I discuss in what ways abiotic stressors such as land use change, pesticides, and climate warming are affecting populations of non-Apis bees. Last, I present a summary of the diversity, transmission routes and prevalence of the most common pathogens affecting non-Apis bees. This chapter provides a broader framework about the ecology and evolution of bees and their importance to assess and improve bee health.