INTRODUCTION

Did you know that more than 4000 species of bees live in the United States and Canada? To put that in perspective, there are 4 times more species of bees in these two countries than all the bird species north of Mexico, 6 times more kinds of bees than butterflies, and about 10 times as many bee species as mammal species. Despite their diversity, few people know anything about bees, even the ones in their own backyards. For example, everyone knows that robins nest in trees, that bears hibernate, and that butterflies start out as caterpillars, but most people don't know where bees live, how they spend the winter, or what they eat. This book is designed to introduce you to the bees of the United States and Canada, including their lifestyles and habitat preferences, and what you can do to attract them to your neighborhood. Understanding bees is beneficial not only to the bees, but also to your gardens.

Over 20,000 species of bees have been identified around the world. New species are being found every year, even in places like New York City. Because new species are continually discovered, scientists estimate that up to 30,000 species might exist worldwide. Bees can be found on every continent (except Antarctica), on small islands, on treeless mountaintops, in jungles and deserts, and on top of high-rises in Chicago. They are most abundant in dry and hot environments, like Mediterranean Europe, and the southwestern United States.

Though the drab reddish-brown honey bee is the default image conjured by most when they hear the word "bee," these creatures are in fact diverse and stunning beauties, and the menagerie includes blue and green jewels like Osmia and Agapostemon, fire-engine red Nomada, jet-black fuzz-balls like Anthophora, and zebra-striped Anthidium. Some of the smallest bees in the world are found in North America. Perdita, found in the southwest United States, measure only 0.1 inch, smaller than George Washington's nose on a quarter. At the other extreme, North America is home to giant bumbling carpenter bees (Xylocopa). At more than an inch long, they sound like miniature helicopters as they hover near flowers.

Bees are thought to increase seed set in 70% of all flowering plants, including many of the fruits and vegetables we enjoy. The special relationship that exists between bees and the flowers they visit is not only economically (and gastronomically) important; it is also unique from a biological perspective. Although there are other organisms that are capable of pollination (and are, in fact, good at it), bees are the only ones to actively gather pollen from the flowers they visit, creating an evolutionary dynamic seen nowhere else in the animal kingdom. Despite the particular talents and unquestionable importance of bees, scientists have reason to believe that some bee species may be experiencing widespread population declines. While the specifics are still being assessed, some things are certain: bees are all around us, they enhance the quality of our lives, and they benefit from our improved understanding of them and their needs.

Our hope is that this book will turn amateur naturalists, gardeners, entomologists, and curious souls on to the amazing lives of the bees that not only reside in untamed wild areas, but also flourish in our very neighborhoods. With understanding comes appreciation; in addition to describing the life stories associated with the many bee species of the United States and Canada, we provide examples of ways to encourage these wonderful pollinators on your own plot of land.

1.1 IS THIS A BEE?

Even though bees are common in most neighborhoods, frequently seen on hikes, and ubiquitous residents of city parks, it is hard to tell whether an insect buzzing nearby is a bee or something else. It's no wonder people get confused. Because bees sting, resembling one is a successful strategy for vulnerable insects, and many a bug has evolved the appearance of a buzzing bee; however, a keen eye and a little practice are all you need to see past the ruse.

Bees and wasps are the most similar in appearance, and they are the most easily confused. It is not uncommon to hear complaints about the "bee" that landed on somebody's hamburger at a recent family picnic. Stories of the pesky nest dangling from a branch in the backyard abound. Hikers complain about the horrible buzzing creatures that swarmed from a log they used as a backrest halfway up the trail. And every summer, someone is attacked by "ground bees" while mowing the lawn. In all cases, the annoying insect was probably not a bee but a wasp. Wasps (including hornets and yellow jackets) and bees are close relatives, sharing in common a grandmother 100 million "greats" ago. In some instances the two are so similar that even trained scientists have difficulty distinguishing them. The bee called Neolarra (see section 9.1), for example, was thought to be a wasp by the first researchers to see it. It didn't help that the bee was dead and stuck to a pin, because the most telling differences between bees and wasps are their mannerisms and day-to-day behaviors.

Most important among these behavioral differences is that bees are pollen eaters. Wasps, in contrast, are meat eaters. While both visit flowers for nectar (the "energy drink" of the insect world), bees also visit flowers in order to collect pollen for their young. On the contrary, wasps pursue other insects and drag them back to the nest for their offspring to devour. This one dietary difference has resulted in very different bearings. To aid in the gathering of pollen, bees are usually hairy (pollen sticks to hair), and many species look like cotton candy with wings. Rooting around in flowers is messy business, and a few minutes rummaging among floral parts leaves a bee coated in hundreds of tiny grains of pollen. Using her many legs, the bee grooms herself, wiping all the pollen to the back of her body, where she stuffs it into the spaces between special stiff bristles on her legs or belly. These tufts or masses of special hairs are called scopa. Quite the opposite of the furry bee, wasps look like Olympic swimmers, devoid of all hair, skinny-waisted, and with long spindly legs.

There are exceptions to every rule, of course. Some bees have scant hair on their bodies and are wasp-thin. In these cases, look for silvery or golden hairs on the face; wasps tend to have glistening mugs, while bee hairs don't shimmer from any angle. Behavior, as mentioned above, can be telling, too. Bees spend more time on flowers than wasps do; wasps in contrast are more likely to raid your backyard barbeque in search of animal proteins accidentally left on a plate.

Since bees and wasps are difficult to distinguish, many stung victims often blame the hapless bee for crimes not committed. The culprit in these cases is likely a paper wasp, a hornet, or a yellow jacket. All live...