Wild Bees and Pollination

Pollination is almost as essential to life as water and oxygen.
— Eric Mader, Assistant Pollinator Program Director, The Xerces Society; Extension Professor of Entomology, Univ. of Minnesota
 Photo by David Cappaert, Michigan State University, Bugwood.org

 Photo by David Cappaert, Michigan State University, Bugwood.org

As you lean on your hoe in that lovingly tended, highly productive early August vegetable patch, do you ever think about who else is helping you to get those vegetables to the table? Sometimes unseen, often unheard, paid only in nectar and pollen, those assistants are absolutely essential to the process of turning flowers into fruit and seed. Pollinators, be they beetles, bees, flies, ants, butterflies, hummingbirds, or bats, are responsible for apples, beans, cranberries, squash, tomatoes, sunflowers and hundreds more. Globally, one out of every three mouthfuls of food depends on a pollinator. And pollinators are in trouble.

 
 

Bees are the most important pollinators in temperate North America. Since there are no native North American honey bees, the introduced European honey bee (social, lives in colonies, makes honey!) is the species of bee most often raised by North American beekeepers. Since the winter of 2006/2007, unusually large numbers of apparently healthy worker honey bees have abandoned their hives en masse, a phenomenon that has come to be called Colony Collapse Disorder. But focusing on Colony Collapse Disorder, which is real and dramatic and troubling (and imperfectly understood), has in many ways obscured the more powerful fact that honey bees have been in accelerating decline for the last seventy years. Why?

Wild bees are struggling as well, perhaps more than the honey bees. I suspect that most of us aren’t aware that there are bees other than honey bees and bumble bees, but in fact there are 20,000 species of bees worldwide, 4000 of them found in the United States, 500 native to Minnesota and Wisconsin. They include sweat bees, orchard mason bees (early spring pollinators), and leafcutter bees (summer pollinators who wrap their eggs into pouches made of pieces of cut leaf). Most wild bees nest either in the ground or in holes in dead wood, stone walls, hollow stems, or other crevices in the landscape. They are docile and hardly ever sting. Although they don’t make honey, they are terrific pollinators because they’ve evolved alongside the flowers that they pollinate. Wild bees’ numbers have been dropping. Some bumble bee species are on the verge of extinction.

 
Nests in soil

Nests in soil

 

What has gone wrong? Of course there is no simple answer to that question; over the last 50 years, almost every change we have made as a society to how we live and how we farm has been unfriendly to bees. We have more concrete, more lawns, more pesticides, and more giant farms growing corn and soybeans. We have fewer weeds and fewer flowers. As individuals who are concerned about the health of bees, there are some things we can’t do much about (bee diseases, bee genetics) but we can make some helpful changes in our relationship to our immediate environment. Make some simple changes, and then persuade your neighbor and their neighbor to do the same. It can make a difference.

 

What CAN you do?

  1. Minimize your pesticide use. Learn to accept imperfection. Think of the “weeds” in your lawn (clover, chickweed, violets) as “grass companions”. Read about integrated pest management.
  2. If you have a garden, plant flowers that appeal to bees: flowers with landing platforms, single flowers, particularly in white, yellow or blue (bees see in the UV range, which means that, unlike hummingbirds, they don’t see red). Be slow to deadhead. Plant in clumps.
  3. Plant natives. This is an important one. Studies of bumblebees show that they prefer natives 4:1 over introduced plants. Dense stands of native flowers give “more bang for the buzz”.
  4. Try to have at least three things flowering in your landscape at all times; critical times are early spring and late fall, think squill and crocuses, goldenrod and asters. Plan your yard vertically (canopy, understory, shrubs, ground layer) to fit in more plants. Reduce or get rid of your lawn.
  5. Include some nesting space for wild bees. Sixty to seventy percent are ground nesters; just leave an area of exposed, undisturbed soil. No mulch, sorry. Thirty to forty percent of wild bees are cavity nesters; except for the carpenter bees, wild bees can’t excavate their own holes, so they need ready-made tunnels. Consider a bee house made of either an untreated, drilled wood block or hollow sticks. Leave rotting dead wood in your yard.
  6. Read. Educate yourself. Educate your neighbor (if your neighbor is using pesticides, I hate to tell you where they are ending up).
  7. Consider becoming a beekeeper. Really, why not?
 
a Bee hotel

a Bee hotel

 
 
 
 
A note on wasps: Wasps are different from bees. Paper wasps, yellow jackets and hornets are all types of wasps. Most wasps are carnivorous predators that feed on insects but have little to do with pollination (one notable exception; the tiny fig wasp which is the sole pollinator of figs). If you have ever been stung at a picnic, it was probably by a wasp, and not by a bee. Foraging bees hardly ever sting. Yellow jackets in August, watch out!

This article was originally written for the Friends School Plant-Sale catalog.