You can help stem bee decline, say speakers at Prairie Day

By: Joel Stottrup, Princeton Union-Eagle
August 25, 2011

University of Minnesota professor Marla Spivak, renowned for her studies on honey bees, points to a slide of a honey bee at work in a honey comb, as part of her presentation at Prairie Day in Princeton.It was the kind of day and place for the pollinating bees to be out and about during the Prairie Day events last Saturday at Prairie Restorations, Inc., located along County Road 45 just south of Princeton city limits.

It was close to 80 degrees with sunny skies and the prairie flowers in the fields at Prairie Restorations were just the thing for honey bees and native bees to hang around in.

Such landscapes are needed more than ever across the countryside now, said two speakers at Prairie Day, as they voiced concern about the decline in numbers of honey bees and native bees.

The speakers were Marla Spivak, a professor in entomology at the University of Minnesota, and Elaine Evans, a graduate student at the U of M. Spivak lectured on honey bees, her specialty for which she has gained much recognition, and Evans talked on native bees. Honey bees are not native to the U.S., Spivak noted.

Both talked about the threats to these insects that are among the pollinators of many vegetables and fruits in the world.

As one of the pamphlets they handed out on bees explains, “pollinators are essential to our world,” and that bees, along with butterflies, hummingbirds, moths, wasps, flies, beetles and some bats, move pollen between flowers, enabling them to produce seeds.

The pamphlet, from the Xerces Society for Invertebrate Conservation, states that these pollinators are necessary for the reproduction of roughly 70 percent of the world’s flowering plants. The resulting seeds and fruits thus provide food for countless other animals ranging from songbirds to grizzly bears, it notes.

The pamphlet adds that pollinators are also essential to human life, in that one of three mouthfuls of food and beverage require the presence of a pollinator. It notes that without pollinators, there would be no apples, pumpkins, blueberries or many other fruits and vegetables.

Prof. Spivak says the decline of bees can be traced to post-World War II when agriculture turned to monoculture crops. She explains that clover, a critical foodstuff for bees, has been left out of corn and soybean rotations in vast Midwestern fields and replaced with synthetic fertilizers.

Also, the use of insecticides, pesticides and fungicides became widespread, which is detrimental to bees, she notes. At the same time, corn is wind pollinated and soybeans self-pollinate so they do not need bees, she adds.

According to Evans, diseases that had shown themselves in commercial bees, have spread to bees in the wild.

Some might recall within the past two decades hearing about the decline in honey bee populations and how a mite was considered one of the causes. Spivak and Evans said that the varroa mite has been a big problem for honey bees for 20 years. Because of these mites wiping out so many honey bees, Spivak and Evans said, there are very few honey bees in North America nesting in trees anymore. They were originally in the wild after escaping commercial colonies, Spivak noted.

Spivak and Evans pointed out differences between bees and wasps, the main one being that wasps have shiny bodies, while bees have fuzzy ones. When people state that bees are bothering them at their picnic, those aren’t bees, but are yellow jackets, a kind of wasp, Spivak explained.

Among the statistics Spivak pointed to in her lecture were:

• The value of United States crops that depend on pollination is $18.9 billion.

• The value worldwide is $217 billion.

• Bees pollinate alfalfa that is eaten by cows and pollination increases coffee yields by 30-40 percent.

• The decline of honey bee numbers began after World War II, but became precipitous since 2006.

You could go to many web sites on the honey bee problem and see that the decline has become a “global phenomenon” rather than just being a U.S. one.

When the decline of honey bees jumped since 2006 scientists called the problem colony collapse disorder, not knowing exactly what it was, Spivak said. Even before that, the number of honey bee colonies dropped from a high of about 6 million in 1945 to about 2 million in 2005, according to the U.S. Department of Agriculture.

Evans’ lecture

Evans, in giving a profile on native bees, said that the world has about 20,000 species of bees, and that North America has about 4,000 bee species. These North American bees collect nectar but don’t produce honey, she noted.

Evans explained that bumblebees are social bees that live in colonies similar to honey bees and that Minnesota has 17 species of bumblebees. Only the queen bumblebees survive the winter in bumble bee colonies, with the queen continuing to build a new colony the next year, Evans said.

Local beekeeper

attests to the decline

Rural Princeton beekeeper Paul Warpeha was asked this week about his experience with honey bees since beginning to keep them about 30 years ago.

It has been “very difficult in the last several years to winter the bees,” he said. “It seems they are not as vigorous going into the winter. Different mites, bacteria, environmental pollution, we are assuming are the causes.”

Warpeha noted bees declining in a hive from a high of 40,000 to 50,000 to a low of only 20,000. When that happens they are not making enough surplus honey to harvest, he explained. His problem with his honey bees has especially been during the winter, he noted, explaining that not as many survive that period.

Warpeha agreed with Spivak and Evans about the decline of bee-friendly crops in today’s agriculture. Yellow and white clover is not planted for forage anymore, he noted.

Warpeha and Spivak also said that alfalfa today is harvested earlier to maximize the amount of protein and that means fewer blooms for the bees to use.

What to do about the problem?

Find alternatives to pesticides, herbicides and fungicides, and enhance bee habitat with trees and forage plants that produce flowers that bees like, Spivak recommended to help stem the decline of bees. Also planting native grasses and flowers help, she said.

Leave some dead trees standing and some bare, untilled ground, along with grassy margins for bees to nest in as well, Spivak said.

The message from Spivak and Evans was clear. That was to try to turn landscapes back to more natural ones with plenty of diversity in flowers. Also leave places for bee nesting. Check out the Xerces Society web site for various recommended plants.

By providing more habitat for bees it could be that humans may also enjoy a more interesting view, one with more variety and color in both plant and animal life.

Read the article in Princeton Union-Eagle


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