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ISU adds to declining honeybees study findings

By Staff | Mar 9, 2014

A PAIR OF researchers work with bee hives at a Cherokee County study site.

AMES – As concern continues to mount over the continuing decline in honey bee numbers, an Iowa State University researcher said there are several causes contributing to the population drop in all pollinators – not just honeybees – around the world.

“Each cause compounds the others,” said Amy Toth, an assistant professor of ecology, evolution and organismal biology at ISU, and one of the researchers in a report released Jan. 30 that analyzed the numbers loss. “People want a single issue to blame it on, and that would be great because we could fix it.

“But it’s not that simple.”

Toth described the decline as “a complex business” with the need to “unravel” all possible causes with each layer of the problem.

“Each factor and layer of the problem leaves the bees (and insects) more susceptible to the next,” she said.

“During planting, some of the treated coating on the seeds rubs off.” —Mary Harris ISU assistant professor of entomology

A good place to start, however, could be the dwindling variety of diet available to pollinators with urban sprawl and expanded agricultural production.

“These two factors have squeezed out in recent decades the diversity of flowering plants giving access to a wide range of flower pollen,” she said.

The resulting diminished nutrition weakens the bees and heightens their vulnerability to pesticides and viruses.

She pointed specifically to those viruses carried by parasitic mites encountered more often in recent years.

“When you combine worsening nutrition with limited habitat and an uptick in viruses, the predicament faced by pollinating insects comes into clearer focus.”

Other researchers and agencies, including the U.S. Department of Agriculture, have shared a similar concern as USDA statistics point to a bee decline of upward to 33 percent each year since the early 2000s.

Andrew Joseph, state apiarist with the Iowa Department of Agriculture and Land Stewardship, said average annual winter American bee losses over the last five years in Iowa is “nearly a third.”

USDA personnel among others citing bee colony collapse disorder as an active factor in the numbers drop – from 5 million in the 1940s to a level of 2.5 million today – is also attempting to accurately pinpoint the cause of the decline.

The agency has described the decline as “a very serious” one that in time can also impact consumers.

Continuing declines the USDA added “threaten the economic viability” of the bee pollination industry.

The agency has described the decline as “a very serious” one that in time can also impacts consumers.

Continuing declines, the USDA added, “threaten the economic viability” of the bee pollination industry.

According to May 1, 2013, report by USDA’s Agricultural Research Service without complete disappearance of the bees can cause an increase in needed pollination services translating into higher food costs for consumers.

The honeybee, a non-native pollinator in the United States, has been seen as a prolific and easy-to-manage pollinator on a commercial level, USDA spokespersons said, citing as one example the almond industry being completely dependent on bees for pollination.

Dr. Mary Harris, an ISU adjunct assistant professor joining with Toth, said she has welcomed the opportunity to contribute research to a team organized by the non-profit California-based Pollinator Partnership to study the cause of the falling honeybee numbers.

The partnership, whose mission is to promote the health of pollinators, critical to food and ecosystems, through conservation, education, and research, has earlier pointed to possible pesticides contamination of near-by healthy plants relied on by pollinating insects.

Harris’ portion of the research was conducted in Buena Vista, Cherokee and O’Brien counties in northwest Iowa with six cooperators. The producers and experimental site owners – four private landowners and ISU’s Allee Memorial Demonstration Farm, in Newell, and Northwest Research Farm, in Sutherland, cooperated with the project allowing the positioning of bee hives next to their corn fields to allow monitoring of the hives and near-by floral resources throughout the growing season.

Commenting on what she observed during her studies she described the picture this way.

“State of the art planters use air pressure and powder lubricants to plant individual seeds,” said, Harris an instructor in natural resource ecology and management. “During planting, some of the treated coating on the seeds rubs off, mixes with the lubricant and is exhausted.

“It’s a dusty process, and that’s what spreads the pesticide,” she said in the release.

“The study doesn’t prove that neonicotinoids (insecticides commonly used to coat seed corn) are responsible for the widespread collapse of bee colonies in Corn Belt states,” Harris said. “But it does show that pollinating insects are being exposed to pesticides inadvertently.

“We have to consider what sort of impact that exposure could be having on them.”

She said her own concerns focus on the “non-target” effects of neonicotinoid seed treatment on insects that are not plant pests.

“I am a proponent and practitioner of IPM, or Integrated Pest Management, in which scouting for pests and determining if pest numbers warrant a treatment or not is a regular part of operations,” she said. “By using any insecticide only when necessary you help maintain that insecticide’s efficacy for when it is needed for control of a specific pest.

“Past experience with the development of resistance to other insecticides has demonstrated what a slippery slope it is to use insecticides prophylactically, “Harris said. “Growers need to plant untreated seed if the pest problem is determined not to exist.

“To do this, growers need to demand their seed suppliers offer untreated seed.”

She further advised growers that if they do need to plant treated seed, they should buy the lower dose treatment and follow all label requirements for reducing the production of dust.

In Sioux City, meanwhile, Leonard Kurtz, a 48-year beekeeper and now retired SueBee Honey employee, terms the dwindling bee numbers resulting from “a tug of war” between chemical companies, food suppliers and producers.

“As the world population continues to grow,” Kurtz said, “the chemical and fertilizer companies and farmers are teaming up for food production efficiency and to maximize the production of every acre.

“In the process, chemicals are being used to control insects and are getting into our food supply. This has had a negative effect and become a burden for the honeybee.”

Nearly $3 million in technical assistance will be provided to farmers and ranchers looking to improve bee health, the USDA Natural Resource Conservation Service announced Tuesday.

The funding is a focused investment to improve pollinator health and will be targeted in five Midwestern states: Michigan, Minnesota, North Dakota, South Dakota and Wisconsin.

Bee health has been under scrutiny recently by the USDA and others looking for answers to an ongoing decline in populations. Bees assist agriculture naturally through crop pollination.

“Honey bee pollination supports an estimated $15 billion worth of agricultural production, including more than 130 fruits and vegetables that are the foundation of a nutritious diet. The future security of America’s food supply depends on healthy honey bees,” Ag Secretary Tom Vilsack noted in a press announcement.

“Expanded support for research, combined with USDA’s other efforts to improve honey bee health, should help America’s beekeepers combat the current, unprecedented loss of honey bee hives each year,” he added.

Pollinator plan

Funding will be provided through the Environmental Quality Incentives Program to promote conservation practices that will provide honey bees with nutritious pollen and nectar while providing benefits to the environment.

Recent studies have shown that beekeepers are losing approximately 30 percent of their honey bee colonies each year, up from historical norms of 10 percent to 15 percent overwintering losses experienced prior to 2006.

This assistance will provide guidance and support to farmers and ranchers to implement conservation practices that will provide safe and diverse food sources for honey bees, USDA said.

For example, appropriate cover crops or rangeland and pasture management may provide a benefit to producers by reducing erosion, increasing the health of their soil, inhibiting invasive species, providing quality forage and habitat for honey bees and other pollinators, as well as habitat for other wildlife.

Midwestern states were chosen because from June to September the region is the resting ground for over 65 percent of the commercially managed honey bees in the country. It is a critical time when bees require abundant and diverse forage across broad landscapes to build up hive strength for the winter.

Applications are due March 21.

Continuing honey bee research

Aside from Tuesday’s funding, the Agricultural Research Service maintains four laboratories across the country conducting research into all aspects of bee genetics, breeding, biology and physiology, with special focus on bee nutrition, control of pathogens and parasites, the effects of pesticide exposure and the interactions between each of these factors.

Other agencies, like the National Institute of Food and Agriculture and the Animal Plant Health Inspection Service also support bee research. APHIS conducts national honey bee pest and disease surveys and provides border inspections to prevent new invasive bee pests from entering the U.S.

The Farm Service Agency and NRCS work on improved forage and habitat for bees through programs such as the Conservation Reserve Program and EQIP. Additionally, the Economic Research Service is currently examining the direct economic costs of the pollinator problem and the associated indirect economic impacts, and the National Agricultural Statistics Service conducts limited surveys of honey production, number of colonies, price, and value of production which provide some data essential for research by the other agencies.

The agencies’ efforts follow a study completed early last year by the U.S. Environmental Protection Agency and the USDA that found several potential reasons for honeybee decline, including poor nutrition and parasites.

The report also recommended additional research and collaboration on honeybee protection and health, including additional review of honeybee pesticide exposure.

The report followed a European Commission temporary ban on selected neonicotinoid pesticides, which have been targeted as a potential cause for honeybee population declines.

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