A key element of any organism's pesticide risk is its natural history, and the routes by which it may be exposed to pesticides in foraging and nesting activities. In this respect, a series of presentations on the natural history of wild bee groups and pesticide exposure were solicited for a session on "Exploring pesticide effects on non-Apis bees" at the X International Symposium on Pollination, convened by the International Commission on Plant-Bee Relations, in Mexico, 27-30 June, 2011. The presentations have been more fully developed for the present publication, as a contribution to knowledge management of pollination services in sustainable agriculture. A careful look at pollinators, as presented in these chapters, can help to understand how they may live and carry out their vital functions in agroecosystems, and how farmers and land managers may mitigate their impacts on key pollinator groups.