In this Issue:

FEATURE ARTICLE

Helping Our Bee Pollinators

VEGETABLE NEWS

Vegetable Insect Pest Update

STRAWBERRY NEWS

Resource for Evaluating Strawberry, Blueberry, and Raspberry Cultivars

APPLE NEWS

The Importance of Pollinators

Weekly Trap Counts

Apple Scab Infections

Identifying Winter Injury in Apple Trees


Order: 2008 Minnesota Vegetable Guide

Insect, Pest Profiles

Vol 5 No. 2   May 16, 2008

Helping Our Bee Pollinators

Marla Spivak, Dept. of Entomology, U of MN, St. Paul, MN

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, which
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 U.S. leading to high losses of honey bee colonies.  This winter, an estimated 35% of U.S. bee colonies died, some from natural causes and others from symptoms specific to CCD.  Those symptoms peaked 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 U.S.  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 applied to 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 that the 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 MN. And the plants from which the bees do derive good protein (pollen) and carbohydrates (nectar) 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 pesticide use and 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

For more ideas and information, see:

 

 

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ACKNOWLEDGEMENTS

Co-Editors: Bill Hutchison (hutch002@umn.edu), Department of Entomology, University of Minnesota, Jeanne Ciborowski, Minnesota Department of Agriculture, Ag. Resources Management and Development Division, and Suzanne Wold-Burkness (woldx018@umn.edu), Department of Entomology, University of Minnesota

The Newsletter is published weekly from May through August, cooperatively, by the Minnesota Department of Agriculture (MDA) and the University of Minnesota (U of MN).  Reports are posted on the U of MN and MDA web sites on Fridays.  If you have suggestions and/or comments, please send your contributions by 4 p.m., Wednesday to Jeanne Ciborowski, 651-201-6217, jeanne.ciborowski@state.mn.us , MDA, 625 Robert St. North, St. Paul, MN  55155.  You can access the Newsletter at the U of MN web site in htm format at: www.vegedge.umn.edu/MNFruit&VegNews/mnindex.htm and at the MDA web site in pdf format at: www.mda.state.mn.us/plants/pestmanagement/ipm/ipmnews.htm

Partial funding for this publication is provided through partnership agreements with the Minnesota Fruit and Vegetable Growers Association (MFVGA) and the United States Department of Agriculture – Risk Management Agency (RMA).  These institutions are equal opportunity providers.

DISCLAIMER

Reference to products in this publication is not intended to be an endorsement to the exclusion of others which may have similar uses. Any person using products listed in this publication assumes full responsibility for their use in accordance with current manufacturer directions.

                    


Last Revised May, 2008 by woldx018@umn.edu
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