Bumble Bees of North America

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