Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Can Bumble Bees Fill Pollination Void?

A recent study at Oregon State University has shown that native bumble bee species have consistently high pollination and seed production levels in red clover.

The findings, which will be published in the November/December 2009 issue of Crop Science, offer promise for the use of bumble bee crop pollinators as an alternative to European honey bees, whose populations have recently declined in many areas of the United States.

Red clover, which is grown for forage and as a rotation crop to improve soil, is raised for seed in western Oregon's Willamette Valley. It will not produce seed without pollination, so growers typically place two to five European honey bee hives on each hectare. However, bee diseases, mites, and colony collapse disorder have recently limited availability and resulted in higher costs for hive rentals. Given these changes, an alternative pollinator for red clover seed crops is needed.

Worldwide there are over 200 species of bumble bees; some of whom are known to pollinate red clover. While commercially reared bumble bee species are available to growers elsewhere, they are considered exotic species in Oregon and cannot be introduced into the state. This leaves Oregon growers dependent on naturally occurring populations of bumble bees as pollinators. However, there is currently no information on the pollination efficiency of native bumble bee species.

Through funding from the Clover Commission, scientists at Oregon State University investigated native bumble bees in commercial fields of red clover seed crops in the Polk County region of the Willamette Valley. Prior to bloom, researchers covered plants with mesh-screened cages. European honey bee hives were placed in some cages and nests of B. vosnesenskii, a native Oregon bumble bee,in others. Some cages were also left vacant. After bloom, seed yield and seed set were compared amongst the different cages. Seed set was also evaluated in four different fields without cages to assess the efficiency of existing bee pollinators. In addition to analyzing seed set, researchers assessed the diversity and abundance of native bumble bees through visual observations of foragers on red clover flowers and through trapping bumble bees in blue vane traps.

While there were no differences in seed yield or average seed set in cages with bumble bees compared to honey bees, the study revealed that variability across cages was lower with bumble bees indicating that bumble bee pollination is more uniform than pollination by European honey bees. The researchers observed that the abundance of bumble bee peaked during mid-to-late bloom. They recorded six species of bumble bees gathering pollen from red clover flowers. Of these, more than 92 percent consisted of B. vosnesenskii, indicating that it is the key pollinator in Oregon. In addition to the six native bumble bee species that were seen gathering pollen from the red clover, 25 more species of native solitary bees, belonging to 12 genera and five families, were collected in the bee traps.

The study has not only documented a great diversity of native bees in synchrony with red clover bloom, but it has also found that seed set was uniform and high across four fields. Under current pollinator regimes, researchers believe red clover seed production is close to its maximum in Oregon.

"To sustain these high yields in Oregon, we must conserve the habitat of bees, use pesticides judiciously and provide floral resources prior to red clover bloom," said Oregon State University entomologist Sujaya Rao, one of the researchers on the study. "Globally, where red clover seed is produced, similar studies are needed. If seed set is found to be well below the maximum, appropriate alternative options such as augmentation with commercial bumble bees could be considered."

Research is ongoing at Oregon State University to determine whether high yields can be achieved by native pollinators alone. If so, European honey bee hive rentals would not be required, and this could lead to more economic red clover seed production in Oregon.

The full article is available for no charge for 30 days following the date of this summary. View the abstract at

Crop Science is the flagship journal of the Crop Science Society of America. Original research is peer-reviewed and published in this highly cited journal. It also contains invited review and interpretation articles and perspectives that offer insight and commentary on recent advances in crop science. For more information, visit

The Crop Science Society of America (CSSA), founded in 1955, is an international scientific society comprised of 6,000+ members with its headquarters in Madison, WI. Members advance the discipline of crop science by acquiring and disseminating information about crop breeding and genetics; crop physiology; crop ecology, management, and quality; seed physiology, production, and technology; turfgrass science; forage and grazinglands; genomics, molecular genetics, and biotechnology; and biomedical and enhanced plants.

CSSA fosters the transfer of knowledge through an array of programs and services, including publications, meetings, career services, and science policy initiatives.

Sara Uttech | Newswise Science News
Further information:

More articles from Agricultural and Forestry Science:

nachricht “How trees coexist” – new findings from biodiversity research published in Nature Communications
21.03.2018 | Technische Universität Dresden

nachricht Earlier flowering of modern winter wheat cultivars
20.03.2018 | Georg-August-Universität Göttingen

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

TRAPPIST-1 planets provide clues to the nature of habitable worlds

21.03.2018 | Physics and Astronomy

The search for dark matter widens

21.03.2018 | Materials Sciences

Natural enemies reduce pesticide use

21.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>