A comprehensive, multi-author treatise on the social insects of the world, with some auxiliary attention to such adjacent topics as subsocial insects and social arachnids. The work is to serve as a very convenient, yet authoritative reference work on the biology and systematics of social insects of the world.  

This is a project of the International Union for the Study of Social Insects (IUSSI), the worldwide organizing body for the scientific study of social insects.