America’s Bee Crisis: Part 2 – Our Big, BEE-utiful World
This is the 2nd part of an ongoing series about the state of bees in America. Read Part 1 to learn how an invasive species, the European honeybee, became the cornerstone of modern industrial agriculture.
CRISIS (from Merriam-Webster): a: an unstable or crucial time or state of affairs in which a decisive change is impending; especially: one with the distinct possibility of a highly undesirable outcome, b: a situation that has reached a critical phase
This is where we find ourselves now. We have built a food system that is entirely divorced from the natural world: we grow crops in areas of low precipitation and drain our rivers to irrigate them; we plant vulnerable monocultures and spray pesticides to protect them; we decimate the local bee populations and then truck in honeybees to serve our needs. For many years this system seemed to work well, but the European honeybee is buckling under the enormous pressure we have put on it to maintain a massive agribusiness model which operates on economies of scale. Can we figure out a way to stave off the ravages of Colony Collapse Disorder and keep this system going for a while longer? Possibly. But, just in case, we should probably have another trick up our sleeve.
America’s Bee Crisis: Part 2 – Our Big, BEE-utiful World
Enter: Native Bees
North America has an estimated 4,000 species of native bees. That’s right – 4,000 different kinds of bees that vary widely in size, appearance, habitat, active season, food preferences, and more! There are so many bees here that they haven’t all been documented. Some form colonies, like honeybees, but most live alone. Some are nearly as big as your thumb, while others are as tiny as a grain of rice. Some are a vibrant, shiny metallic green, while others are black and inconspicuous. They can live in hives, or in the ground, or in hollow reeds, or holes in wood. With such a wide variety of bees to choose from, it seems kind of silly that we’ve picked just one to be our partner in pollination, doesn’t it?
What is a Bee?
With so many striking differences between the various species of bees, you might be wondering: “What makes a bug a bee, anyway?” Bees belong to an order of insects called Hymenoptera. All bees share some common features: a head with two long antennae and two large compound eyes on the sides; a thorax where the wings and legs are connected; two sets of wings; and a long abdomen that is very flexible. Their most notable physical characteristic is a“wasp waist,” or a narrowing of the abdomen where it connects to the thorax. Bees also have tongues for drinking nectar and mandibles (jaws) for constructing their nests. Bees build nests to protect their young from predators and the elements. They provide their young with food – pollen and nectar – and have special hairs for pollen collection.
A Bee is not a Fly
Flies belong to an order of insects called Diptera. Their bodies are stout and they have only one set of wings. Their two large compound eyes are near the top of their heads, and they have short, stubby antennae. They do not possess stingers. Flies also lack mandibles because they do not construct nests for their young. Nor do they gather food, so they have no specialized hairs for pollen collection. Instead they lay their eggs on or near a food source and do not return. Fly larvae are often predators on other garden insects, such as aphids, and are beneficial. Flower flies mimic bees in their coloring and feed on nectar and pollen, serving as minor pollinators.
A Bee is not a Wasp
Bees and wasps are cousins, and they have many traits in common. The main difference between them is that wasps are predators and bees are vegetarians. Instead of pollen and nectar, wasps feed their young other insects – aphids and caterpillars that they find in your garden. Wasps lack hairs on their bodies for collecting pollen, and their coloring is very striking. Their overall appearance is more menacing. Wasps are in general more aggressive than bees, and some species have a reputation for harassing picnickers. However, wasps are beneficial for your garden because they feed on undesirable insects and visit flowers for nectar, serving as minor pollinators.
Bees – The Best Pollinators
Because bees are vegetarians who gather pollen to feed their young, they are the rock stars of pollination! Bees have adapted to this diet by growing special hairs on their bodies for collecting pollen. Pollen sticks to their hairs while they forage; later bits of it will fall off on other flowers they are visiting, achieving pollination. Flowers have thus evolved to attract bees, both by displaying colors bees find alluring, and by offering them nectar, a sugary liquid bees drink to fuel their flights. Other insects and birds also enjoy drinking nectar and even pollinate flowers while they do, but bees are hands-down the champions of pollinators because of their pollen-gathering efforts.
Most of us tend to think of bees as social creatures who live in large colonies. We’re familiar with the idea of queens and workers, hives and honey. Social bees actually make up a minority of bee species, but their way of life is so successful that they are the most familiar pollinator in home gardens. Honeybees are the most famous social bees. They construct large hives housing many thousands of bees. Hive maintenance is delegated to the worker bees, who are all sisters, while their mother, the queen, spends her life laying eggs. Honeybee hives are perennial, lasting 2-3 years. Because honeybee colonies persist through the winter months, they must store large quantities of honey to sustain themselves when no forage is available. Their honey and their queen are so invaluable that honeybees guard the hive at all times.
Bumblebees are another social bee. Their colonies are similar in structure to the honeybee’s but much smaller in scale. A bumblebee colony will usually house just a few dozen adults. Bumblebee colonies are are short-lived: the bees of the colony are very active throughout the warm seasons, but as cold weather sets in they make new queens who hibernate underground during winter. The rest of the bees perish as cold weather sets in. The following spring the hibernating queens awake to start new colonies. Bumblebees will sting to defend their hive if it is disturbed.
Most of the rest of the 4,000 different kinds of bees in America are solitary bees. These bees have no hives, and they make no honey. Instead, each female bee does her own thing. She builds her own little nest and lays her own eggs in it and fills it with food for her young. The solitary bee works ceaselessly to build and provision a nest – often working herself to death. Her life’s purpose is only to lay as many eggs as possible before dying.
Solitary bees nest in a lot of different places, but most of their nests have some common characteristics: they will generally nest in some sort of tunnel which is not much wider than their own bodies, they will provide each egg with its own nest chamber and food source, and they will lay their eggs on or very near a cache of pollen moistened with nectar. Some solitary bees build their nests by burrowing a tunnel in the ground that has little branches off to the sides with chambers for their eggs. Others use hollow reeds, separating the eggs with partitions made of mud, leaves, or flower petals. They may also make use of holes bored in wood by other insects. Solitary bees spend most of their lives within these nest chambers, in a pupal state. They hibernate within the nest chamber and do not emerge until the following year.
The Gentlest Pollinators
Because solitary bees work alone and lay each egg in its own little space and do not make honey, they are the gentlest bees. They have no hive to protect, no honey stash to defend, and nobody to team up with in the event of an intruder. In a fight or flight situation they will always choose flight, because they want only to live to lay more eggs. If one nest site is disturbed they can find another. Solitary bees never swarm because they have no sister bees to rally to their defenses.
So, now you know what a bee is and why they excel as pollinators. However, not all bees gather pollen in the same way, and it turns out that some bees are better pollinators than others, and our native bees are often better pollinators than honeybees.
More on that in Part 3. 🙂
P.S. This is a series of blog posts that will include a giveaway of 2 complete mason bee kits; be sure to follow me here and on Facebook so you won’t miss an installment!
The Nitty Gritty
Since acquiring my mason bees in 2008 I have developed a passionate interest in bees in general, and solitary bees in particular. This series is a culmination of my last 6 years spent reading books, scientific studies, and news articles, as well as observing bees in the wild. For further reading on this topic, I suggest:
For information about bee anatomy, life cycle, nesting habits, and more: Bees of the World, by Chistopher O’Toole & Anthony Raw (out of print), and Bees, Wasps, and Ants by Eric Grissell.
For further comparison of bees with wasps and flower flies: Attracting Native Pollinators, by The Xerces Society.