The stingless bees are one of the most diverse, attractive, fascinating, conspicuous and useful of all the insect groups of the tropical world. This is a formidable and contentious claim but I believe it can be backed up. They are fifty times more species rich than the honey bees, the other tribe of highly eusocial bees. They are ubiquitous in the tropics and thrive in tropical cities. In rural areas, they nest in a diversity of sites and are found on the flowers of a broad diversity of crop plants. Their role in natural systems is barely studied but they almost certainly deserve that hallowed title of keystone species. They are popular with the general public and are greatly appreciated in zoos and gardens. The chapters of this book provide abundant further evidence of the ecological and economic importance of stingless bees.