The product of more than twenty years of study and field experience, this book is the first new work on the masarine wasps in over 30 years. In one volume it gathers current data on: biogeography, life history, nest-building behaviour, myriad flower associations, and associated insects and other microfauna. The role of these insects as potential pollinators of forage crops in southern Africa and the trends in land use in this part of the world as it impacts on their biodiversity is also considered.