Paul H. Williams is a research entomologist at the Natural History Museum in London. Robbin W. Thorp is professor emeritus of entomology at the University of California, Davis. Leif L. Richardson is a doctoral candidate in the Department of Ecology and Evolutionary Biology at Dartmouth College. Sheila R. Colla is an NSERC postdoctoral fellow and project leader at Wildlife Preservation Canada.

• Introduction 7 Observing Bumble Bees 17 Attracting Bumble Bees 20 Bumble Bee Forage Guide by Ecoregion 22 Maps and Seasonal Activity 29 Bumble Bee Decline and Conservation 31 Threats to Bumble Bees 33 Natural Enemies 35 Mimicry 38 Distinguishing Bumble Bees from Other Insects 42 Bumble Bee Names and Classification 45 How to Use This Book to Identify Bumble Bee Species 48 Species Accounts 51 SQUARE- OR LONG-CHEEKED BEES WITH A ROUNDED ANGLE ON THE MIDLEG - Bombus vosnesenskii 52 - Bombus caliginosus 54 - Bombus vandykei 57 - Bombus impatiens 59 - Bombus bimaculatus 62 - Bombus perplexus 64 - Bombus vagans 67 - Bombus sandersoni 70 - Bombus jonellus 73 - Bombus frigidus 75 - Bombus mixtus 77 - Bombus ternarius 80 - Bombus huntii 82 - Bombus sylvicola 84 - Bombus melanopygus 87 - Bombus bifarius 90 - Bombus centralis 93 - Bombus flavifrons 95 - Bombus sitkensis 98 - Bombus polaris 100 - Bombus balteatus 103 - Bombus neoboreus 105 - Bombus hyperboreus 108 SHORT-CHEEKED BEES WITH A ROUNDED ANGLE ON THE MIDLEG - Bombus terricola 111 - Bombus occidentalis 114 - Bombus cryptarum 117 - Bombus franklini 119 - Bombus affinis 121 - Bombus griseocollis 123 - Bombus morrisoni 126 - Bombus fraternus 128 - Bombus crotchii 130 - Bombus rufocinctus 133 MEDIUM- OR LONG-CHEEKED BEES WITH A SHARP ANGLE ON THE MIDLET - Bombus fervidus 136 - Bombus borealis 139 - Bombus distinguendus 142 - Bombus appositus 144 - Bombus pensylvanicus 147 - Bombus auricomus 150 - Bombus nevadensis 152 HINDLEG (TIBIA) WITH THE OUTER SURFACE UNIFORMLY CONVEX AND DENSELY HAIRY (CUCKOO BUMBLE BEES, NO WORKERS) - Bombus citrinus 155 - Bombus variabilis 157 - Bombus insularis 159 - Bombus bohemicus 161 - Bombus suckleyi 163 - Bombus flavidus 165 Identification Keys to Female and Male Bumble Bees, with Photos 168 Glossary 199 Additional Resources 203 Acknowledgments 204 Photo Credits 206 Index 207

Winner of a 2015 Outstanding Reference Sources Award, Reference and User Services Association, American Library Association "A very helpful guide for any one interested in bumble bees."--Amanda Williams, buzzaboutbees.net "As bee populations plummet and environmental concerns continue to make the news, there is widespread interest in bees. This attractively priced guide helps users identify the 46 species found north of Mexico and offers insight into their ecology and habitats... This guide will be useful in public and academic libraries where there is an interest in bees or the environment."--Rebecca Vnuk, Booklist "Identif[ies] the 46 species of bumblebee that are found in North America (Mexico is not included), far more than previous guides. The introduction presents clear information on these bees generally, their distribution, colony cycle, and interactions with plants... An attractive, worthwhile purchase."--Margaret Heilbrun, Library Journal "Because of their importance as a pollinator, their ubiquity (in various species, of course) across the continent, and simply because the lives and behaviors bumble bees are so fascinating, Bumble Bees of North America should be considered as a must-read by all amateur naturalists. Professionals--be they entomologists, ecologists, general biologists, and most especially teachers of life science subjects at all levels--would also do well to add it to their reading lists for both its superb introduction to the genus as well as its value as a reference guide."--John Riutta, Well-read Naturalist "The timely arrival of Bumble Bees of North America on bookstore shelves is as welcome as its namesake insects are in gardens... Given that the last comprehensive guide to North American bumble bees was published in 1913, Williams, Thorps, Richardson, and Colla's Bumble Bees of North America offers a much?needed review of the status and identification of the 46 bumble bee species north of Mexico... [A] much?needed milestone in the ability of scientists and citizens alike to sort bee species found afield and at home. With bees on the decline, the ability to identify and inventory the buzz in our backyards may prove critical in future conservation efforts."--Matthew Bettelheim, (bio)accumulation "[T]his book [is] a useful addition to any gardener or wildlife watcher's library. The really nice thing about this guide is the number and quality of the photographs they provide: I really need to get a copy of this book to help me identify the bumble bees I catch in my surveys."--AC, Wildlife Activist "Accessible to both the layman and serious apiologist. Carefully organized, it begins with an introduction that is a must-read before moving on to the comprehensive bumble bee ID guide... I commend this book to all lovers of native plants."--Harold Smith, Blazing Star, publication of The North American Native Plant Society "This reasonably priced, attractive volume with excellent photographs and color plates will be valuable to professionals as well as anyone interested in identifying or learning more about bumblebees."--Choice "I encourage all melittologists to obtain a copy for ready use, as well as anyone interested in the conservation, ecology, biology, natural history, or simple appreciation of bumble bees."--Michael S. Engel, Entomologist's Monthly "[A] most desirable book. Each species is beautifully photographed and then described in detail, with maps and identification markings as well as comprehensive text to inform you about the particular bee in question."--Mary Montaut, An Beachaire "This is a very well-written book which presents and updates information from a wide range of sources in a very readable and clear way."--Mike Edwards, Journal of the British Entomology and Natural History Society "Bumble Bees of North America has not only provided casual observers and professionals with a comprehensive treatment of North American bumblebees, it has delivered utility while preserving aesthetics."--Samuel O'Dell, Prairie Naturalist "This book is primarily an identification manual that also describes the distribution of the species. It is the perfect size for a field guide but it may be even more helpful when you are using microscopic characteristics for identification. The Bumble Bees of North America is also an invaluable reference for those of us who want to learn about and identify which bumble bees are our neighbours."--Tracy Ferreira, Bulletin of the Entomological Society of Canada

Paul H. Williams is a research entomologist at the Natural History Museum in London. Robbin W. Thorp is professor emeritus of entomology at the University of California, Davis. Leif L. Richardson is a doctoral candidate in the Department of Ecology and Evolutionary Biology at Dartmouth College. Sheila R. Colla is an NSERC postdoctoral fellow and project leader at Wildlife Preservation Canada.

• Introduction 7 Observing Bumble Bees 17 Attracting Bumble Bees 20 Bumble Bee Forage Guide by Ecoregion 22 Maps and Seasonal Activity 29 Bumble Bee Decline and Conservation 31 Threats to Bumble Bees 33 Natural Enemies 35 Mimicry 38 Distinguishing Bumble Bees from Other Insects 42 Bumble Bee Names and Classification 45 How to Use This Book to Identify Bumble Bee Species 48 Species Accounts 51 SQUARE- OR LONG-CHEEKED BEES WITH A ROUNDED ANGLE ON THE MIDLEG - Bombus vosnesenskii 52 - Bombus caliginosus 54 - Bombus vandykei 57 - Bombus impatiens 59 - Bombus bimaculatus 62 - Bombus perplexus 64 - Bombus vagans 67 - Bombus sandersoni 70 - Bombus jonellus 73 - Bombus frigidus 75 - Bombus mixtus 77 - Bombus ternarius 80 - Bombus huntii 82 - Bombus sylvicola 84 - Bombus melanopygus 87 - Bombus bifarius 90 - Bombus centralis 93 - Bombus flavifrons 95 - Bombus sitkensis 98 - Bombus polaris 100 - Bombus balteatus 103 - Bombus neoboreus 105 - Bombus hyperboreus 108 SHORT-CHEEKED BEES WITH A ROUNDED ANGLE ON THE MIDLEG - Bombus terricola 111 - Bombus occidentalis 114 - Bombus cryptarum 117 - Bombus franklini 119 - Bombus affinis 121 - Bombus griseocollis 123 - Bombus morrisoni 126 - Bombus fraternus 128 - Bombus crotchii 130 - Bombus rufocinctus 133 MEDIUM- OR LONG-CHEEKED BEES WITH A SHARP ANGLE ON THE MIDLET - Bombus fervidus 136 - Bombus borealis 139 - Bombus distinguendus 142 - Bombus appositus 144 - Bombus pensylvanicus 147 - Bombus auricomus 150 - Bombus nevadensis 152 HINDLEG (TIBIA) WITH THE OUTER SURFACE UNIFORMLY CONVEX AND DENSELY HAIRY (CUCKOO BUMBLE BEES, NO WORKERS) - Bombus citrinus 155 - Bombus variabilis 157 - Bombus insularis 159 - Bombus bohemicus 161 - Bombus suckleyi 163 - Bombus flavidus 165 Identification Keys to Female and Male Bumble Bees, with Photos 168 Glossary 199 Additional Resources 203 Acknowledgments 204 Photo Credits 206 Index 207

Winner of a 2015 Outstanding Reference Sources Award, Reference and User Services Association, American Library Association "A very helpful guide for any one interested in bumble bees."--Amanda Williams, buzzaboutbees.net "As bee populations plummet and environmental concerns continue to make the news, there is widespread interest in bees. This attractively priced guide helps users identify the 46 species found north of Mexico and offers insight into their ecology and habitats... This guide will be useful in public and academic libraries where there is an interest in bees or the environment."--Rebecca Vnuk, Booklist "Identif[ies] the 46 species of bumblebee that are found in North America (Mexico is not included), far more than previous guides. The introduction presents clear information on these bees generally, their distribution, colony cycle, and interactions with plants... An attractive, worthwhile purchase."--Margaret Heilbrun, Library Journal "Because of their importance as a pollinator, their ubiquity (in various species, of course) across the continent, and simply because the lives and behaviors bumble bees are so fascinating, Bumble Bees of North America should be considered as a must-read by all amateur naturalists. Professionals--be they entomologists, ecologists, general biologists, and most especially teachers of life science subjects at all levels--would also do well to add it to their reading lists for both its superb introduction to the genus as well as its value as a reference guide."--John Riutta, Well-read Naturalist "The timely arrival of Bumble Bees of North America on bookstore shelves is as welcome as its namesake insects are in gardens... Given that the last comprehensive guide to North American bumble bees was published in 1913, Williams, Thorps, Richardson, and Colla's Bumble Bees of North America offers a much?needed review of the status and identification of the 46 bumble bee species north of Mexico... [A] much?needed milestone in the ability of scientists and citizens alike to sort bee species found afield and at home. With bees on the decline, the ability to identify and inventory the buzz in our backyards may prove critical in future conservation efforts."--Matthew Bettelheim, (bio)accumulation "[T]his book [is] a useful addition to any gardener or wildlife watcher's library. The really nice thing about this guide is the number and quality of the photographs they provide: I really need to get a copy of this book to help me identify the bumble bees I catch in my surveys."--AC, Wildlife Activist "Accessible to both the layman and serious apiologist. Carefully organized, it begins with an introduction that is a must-read before moving on to the comprehensive bumble bee ID guide... I commend this book to all lovers of native plants."--Harold Smith, Blazing Star, publication of The North American Native Plant Society "This reasonably priced, attractive volume with excellent photographs and color plates will be valuable to professionals as well as anyone interested in identifying or learning more about bumblebees."--Choice "I encourage all melittologists to obtain a copy for ready use, as well as anyone interested in the conservation, ecology, biology, natural history, or simple appreciation of bumble bees."--Michael S. Engel, Entomologist's Monthly "[A] most desirable book. Each species is beautifully photographed and then described in detail, with maps and identification markings as well as comprehensive text to inform you about the particular bee in question."--Mary Montaut, An Beachaire "This is a very well-written book which presents and updates information from a wide range of sources in a very readable and clear way."--Mike Edwards, Journal of the British Entomology and Natural History Society "Bumble Bees of North America has not only provided casual observers and professionals with a comprehensive treatment of North American bumblebees, it has delivered utility while preserving aesthetics."--Samuel O'Dell, Prairie Naturalist "This book is primarily an identification manual that also describes the distribution of the species. It is the perfect size for a field guide but it may be even more helpful when you are using microscopic characteristics for identification. The Bumble Bees of North America is also an invaluable reference for those of us who want to learn about and identify which bumble bees are our neighbours."--Tracy Ferreira, Bulletin of the Entomological Society of Canada

Paul H. Williams is a research entomologist at the Natural History Museum in London. Robbin W. Thorp is professor emeritus of entomology at the University of California, Davis. Leif L. Richardson is a doctoral candidate in the Department of Ecology and Evolutionary Biology at Dartmouth College. Sheila R. Colla is an NSERC postdoctoral fellow and project leader at Wildlife Preservation Canada.

• Introduction 7 Observing Bumble Bees 17 Attracting Bumble Bees 20 Bumble Bee Forage Guide by Ecoregion 22 Maps and Seasonal Activity 29 Bumble Bee Decline and Conservation 31 Threats to Bumble Bees 33 Natural Enemies 35 Mimicry 38 Distinguishing Bumble Bees from Other Insects 42 Bumble Bee Names and Classification 45 How to Use This Book to Identify Bumble Bee Species 48 Species Accounts 51 SQUARE- OR LONG-CHEEKED BEES WITH A ROUNDED ANGLE ON THE MIDLEG - Bombus vosnesenskii 52 - Bombus caliginosus 54 - Bombus vandykei 57 - Bombus impatiens 59 - Bombus bimaculatus 62 - Bombus perplexus 64 - Bombus vagans 67 - Bombus sandersoni 70 - Bombus jonellus 73 - Bombus frigidus 75 - Bombus mixtus 77 - Bombus ternarius 80 - Bombus huntii 82 - Bombus sylvicola 84 - Bombus melanopygus 87 - Bombus bifarius 90 - Bombus centralis 93 - Bombus flavifrons 95 - Bombus sitkensis 98 - Bombus polaris 100 - Bombus balteatus 103 - Bombus neoboreus 105 - Bombus hyperboreus 108 SHORT-CHEEKED BEES WITH A ROUNDED ANGLE ON THE MIDLEG - Bombus terricola 111 - Bombus occidentalis 114 - Bombus cryptarum 117 - Bombus franklini 119 - Bombus affinis 121 - Bombus griseocollis 123 - Bombus morrisoni 126 - Bombus fraternus 128 - Bombus crotchii 130 - Bombus rufocinctus 133 MEDIUM- OR LONG-CHEEKED BEES WITH A SHARP ANGLE ON THE MIDLET - Bombus fervidus 136 - Bombus borealis 139 - Bombus distinguendus 142 - Bombus appositus 144 - Bombus pensylvanicus 147 - Bombus auricomus 150 - Bombus nevadensis 152 HINDLEG (TIBIA) WITH THE OUTER SURFACE UNIFORMLY CONVEX AND DENSELY HAIRY (CUCKOO BUMBLE BEES, NO WORKERS) - Bombus citrinus 155 - Bombus variabilis 157 - Bombus insularis 159 - Bombus bohemicus 161 - Bombus suckleyi 163 - Bombus flavidus 165 Identification Keys to Female and Male Bumble Bees, with Photos 168 Glossary 199 Additional Resources 203 Acknowledgments 204 Photo Credits 206 Index 207

Winner of a 2015 Outstanding Reference Sources Award, Reference and User Services Association, American Library Association "A very helpful guide for any one interested in bumble bees."--Amanda Williams, buzzaboutbees.net "As bee populations plummet and environmental concerns continue to make the news, there is widespread interest in bees. This attractively priced guide helps users identify the 46 species found north of Mexico and offers insight into their ecology and habitats... This guide will be useful in public and academic libraries where there is an interest in bees or the environment."--Rebecca Vnuk, Booklist "Identif[ies] the 46 species of bumblebee that are found in North America (Mexico is not included), far more than previous guides. The introduction presents clear information on these bees generally, their distribution, colony cycle, and interactions with plants... An attractive, worthwhile purchase."--Margaret Heilbrun, Library Journal "Because of their importance as a pollinator, their ubiquity (in various species, of course) across the continent, and simply because the lives and behaviors bumble bees are so fascinating, Bumble Bees of North America should be considered as a must-read by all amateur naturalists. Professionals--be they entomologists, ecologists, general biologists, and most especially teachers of life science subjects at all levels--would also do well to add it to their reading lists for both its superb introduction to the genus as well as its value as a reference guide."--John Riutta, Well-read Naturalist "The timely arrival of Bumble Bees of North America on bookstore shelves is as welcome as its namesake insects are in gardens... Given that the last comprehensive guide to North American bumble bees was published in 1913, Williams, Thorps, Richardson, and Colla's Bumble Bees of North America offers a much?needed review of the status and identification of the 46 bumble bee species north of Mexico... [A] much?needed milestone in the ability of scientists and citizens alike to sort bee species found afield and at home. With bees on the decline, the ability to identify and inventory the buzz in our backyards may prove critical in future conservation efforts."--Matthew Bettelheim, (bio)accumulation "[T]his book [is] a useful addition to any gardener or wildlife watcher's library. The really nice thing about this guide is the number and quality of the photographs they provide: I really need to get a copy of this book to help me identify the bumble bees I catch in my surveys."--AC, Wildlife Activist "Accessible to both the layman and serious apiologist. Carefully organized, it begins with an introduction that is a must-read before moving on to the comprehensive bumble bee ID guide... I commend this book to all lovers of native plants."--Harold Smith, Blazing Star, publication of The North American Native Plant Society "This reasonably priced, attractive volume with excellent photographs and color plates will be valuable to professionals as well as anyone interested in identifying or learning more about bumblebees."--Choice "I encourage all melittologists to obtain a copy for ready use, as well as anyone interested in the conservation, ecology, biology, natural history, or simple appreciation of bumble bees."--Michael S. Engel, Entomologist's Monthly "[A] most desirable book. Each species is beautifully photographed and then described in detail, with maps and identification markings as well as comprehensive text to inform you about the particular bee in question."--Mary Montaut, An Beachaire "This is a very well-written book which presents and updates information from a wide range of sources in a very readable and clear way."--Mike Edwards, Journal of the British Entomology and Natural History Society "Bumble Bees of North America has not only provided casual observers and professionals with a comprehensive treatment of North American bumblebees, it has delivered utility while preserving aesthetics."--Samuel O'Dell, Prairie Naturalist "This book is primarily an identification manual that also describes the distribution of the species. It is the perfect size for a field guide but it may be even more helpful when you are using microscopic characteristics for identification. The Bumble Bees of North America is also an invaluable reference for those of us who want to learn about and identify which bumble bees are our neighbours."--Tracy Ferreira, Bulletin of the Entomological Society of Canada