This guide allows amateur and professional naturalists to identify all 46 bumble bee species found north of Mexico and to understand their ecology and changing geographic distributions.-- Source other than Library of Congress.

Introduction -- Observing bumble bees -- Attracting bumble bees -- Bumble bee forage guide by ecoregion -- Maps and seasonal activity -- Bumble bee decline and conservation -- Threats to bumble bees -- Natural enemies -- Mimicry -- Distinguishing bumble bees from other insects -- Bumble bee names and classification -- How to use this book to identify bumble bee species -- Species accounts -- Square-or long-cheeked bees with a rounded angle on the midleg -- Short-cheeked bees with a rounded angle on the midleg -- Medium- or long-cheeked bees with a sharp angle on the midleg -- Hindleg (tibia) with the outer surface uniformly convex and densely hairy (cuckoo bumble bees, no workers).