Utah Pest News Summer 2010

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News from the USDA-ARS Pollinating Insects—Biology, Management and Systematics Research Unit in Logan, UT

By Rosalind James, Research Leader of the “Logan Bee Lab” on the Utah State University Campus. Click here for website.

bee lab shot
Rosalind James (front) and Theresa Pitts-Singer collect field samples in an alfalfa leafcutting bee shelter in an alfalfa seed field in Cove, UT.
healthy mature leafcutting larva bee larva sporulating chalkbrood disease
One of the lab’s projects is developing methods to improve the health of the alfalfa leafcutting bee.  On the left is a healthy bee larva, and on the right is a larva infested by the fungal-caused chalkbrood disease. 

With the warmth of summer sun comes the first round of flowers that are quietly being pollinated by bees.  Most of us are familiar with the honey bee, as it buzzes around flowers gathering nectar and pollen, creating stores of sweet, golden honey.  But in addition to the honey bee there are several other bees, some smaller, some larger, all with their own interesting life stories.  North America is the native home of some 3500 different species of bees, and Utah is the native home to just over 1500 of those.

The Pollinating Insects Laboratory is part the USDA Agricultural Research Service, located in Logan, UT, on the Utah State University campus.  We specialize in the study of these native bees, the ones that so often go unnoticed by the casual observer.  Most people are familiar with the large, fuzzy, black and yellow bumble bee, but even that is not only one species, but actually many different species. Unfortunately, bumble bees are in a crisis.  At least five North American species are disappearing, with one species thought to have already gone extinct within the last 5 years.  We have developed a method for determining the extent and cause of these losses using geographic information systems (GIS) and historic records of bumble bee collections, creating models that predict the geographic range of bees at different times in history. These models will help scientists identify possible causes for the disappearance of these bees.

Another bee extensively studied by our research group is the alfalfa leafcutting bee, which is used by alfalfa seed growers for pollination.  Unlike honey bees and bumble bees, the alfalfa leafcutting bee is a solitary bee, meaning that it does not form large colonies headed by a queen.  Instead, every female forms her own nest and lays eggs, in this case the nests are built inside holes in wood, or most any hole a female can find that is the right size.

Alfalfa seed growers are actually beekeepers of this special bee, and release them in their fields with boards containing rows and rows of holes made for the bees to nest in.  You may have seen the shelters for these bees in alfalfa seed fields as you drive by on the highways.  Unfortunately, this bee is prone to health problems in the U.S., and most leafcutting bees used in the U.S. are imported from Canada.

Approximately 30 million leafcutting bees are imported into Utah from Canada every year.  Nationwide, it is approximately 2 billion bees—although these are really purchased by the gallon, so more accurately, about 200,000 gallons a year.  Our laboratory is working on developing methods to improve the health of U.S. bees, and have made some important discoveries about the immune system in leafcutting bees, and how weather and pesticide use can keep this bee from reproducing successfully.

The blue orchard bee is also a solitary bee.  It nests in the spring, making it an excellent pollinator for fruit trees like cherries, apples, pears, and almonds. Utah is among the top two suppliers of blue orchard bees for California almond pollination, and this market is the direct result of methods developed by our laboratory.  We continue to work to improve the effectiveness of this bee for almond production.

Meanwhile, we also have worked for many years to better understand the diversity of bees in the West, and the importance of our wild bees for pollination of native plants.  Our laboratory houses the National Pollinating Insect Collection, and serves as an important taxonomic resource for scientists who study pollination.  We have documented the diversity of bees from several national parks in the West, including Escalante National Monument, Zion National Park, Yosemite National Park, and the Pinnacles National Monument, helping to build a catalog of bees, and identifying several new species in the process.  The mission of the Pollinating Insects Research Unit is to help keep our pollinators safe, for both food production and sustaining our wildlands, and to increase public awareness of the importance of native bees.