Helping our Bee Pollinators

Marla Spivak
Department of Entomology, University of Minnesota

Lady Bird Johnson had a great vision. In her words: “My special cause, the one that alerts my interest and quickens the pace of my life, is to preserve the wildflowers and native plants that define the regions of our land-to encourage and promote their use in appropriate areas and thus help pass on to generations in waiting the quiet joys and satisfactions I have known since my childhood…Though the word beautification makes the concept sound merely cosmetic, it involves much more: clean water, clean air, clean roadsides, safe waste disposal and preservation of valued old landmarks as well as great parks and wilderness areas. To me…beautification means our total concern for the physical and human quality we pass on to our children and the future. The environment is where we all meet; where all have a mutual interest; it is the one thing all of us share. It is not only a mirror of ourselves, but a focusing lens on what we can become.”

If I could add anything to what Lady Bird said, it would be: Planting and preserving wildflowers and native plants also provides refuges for our declining native and non-native bees, who, in turn, help propagate the flowers through pollination.

The decline of honey bees has received much public interest in the last two years, as an event called Colony Collapse Disorder (CCD) continues to sweep through the US leading to high losses of honey bee colonies. This winter, an estimated 35% of US bee colonies died, some from natural causes and others from symptoms specific to CCD. Those symptoms are the ones that piqued the interest of the press: colonies inexplicably and suddenly lose most of their adult population, and the dead bees are nowhere to be found.

The cause of this sudden collapse of bee colonies is still being investigated. Preliminary studies indicate that CCD is likely due to a combination of viruses and a single-celled gut parasite called nosema. Nosema is a formidable pathogen on its own, and in combination with viruses, seems to be even more virulent. There are two species of nosema that affect honey bees: Nosema apis and N. ceranae; the latter is a relatively new pathogen in the US Honey bees are particularly susceptible to these pathogens because there is evidence that their immune systems are weakened by a combination of things: 1) Parasitic mites (Varroa destructor) that shorten the lifespan and weaken bees; 2) Pesticides that we apply to our urban- and agro-ecosystems which can have sub-lethal and cumulative effects on bees, and, 3) Paucity of flowers which leads to low nutritional diversity and quality for bees. The fact is, increasing acreage of monoculture crops leads to lower plant diversity. Bees derive virtually no nutritional benefit from corn and soybeans; these crops are deserts for bees in Minnesota. And the plants the bees do derive good protein (pollen) and carbohydrates (nectar) from are often contaminated with insecticides or dead from herbicides.

Our native bee pollinators are also in decline, but not from the CCD symptoms. Native bees include bumble bees (Bombus sp), ground and twig-nesting bees (Andrenidae), sweat bees (Halictidae), leafcutter bees and orchard mason bees (Megachilidae); all beautiful and important pollinators. They are in decline due to our pesticide use and our land use, which limits their nesting sites and nutritional resources.

What can we do? Follow Lady Bird’s advice: Plant flowers. Take a moment to visit the Lady Bird Johnson Wildflower Center website through the University of Texas, Austin (www.wildflower.org). If you have driven through Texas, you know that the roadsides are awash with flowers. Promote the same effort in Minnesota! It would beautify our environment, make our drives much more interesting and pleasant, and would be the best possible gift to our bee pollinators we could offer. We also should promote plantings of bee conservation strips along agricultural field edges and in urban areas such as parks and golf courses to provide refuges for our pollinators. Seed mixes can be designed that bloom over the course of the season to provide continuous resources.

“Some may wonder why I chose wildflowers when there are hunger and unemployment and the big bomb in the world. Well, I, for one, think we will survive, and I hope that along the way we can keep alive our experience with the flowering earth. For the bounty of nature is also one of the deep needs of man.” -Lady Bird Johnson.-

Read Up

Pollinator Conservation Handbook, by M. Shepherd, SL Buchmann, M. Vaughan, S. Hoffman Black, The Xerces Society, 2003.

Helping Pollinators

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