Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Selenium impacts honey bee behavior and survival

26.04.2012
UC Riverside entomologists develop 'proof of concept' that selenium may negatively impact honey bee populations at selenium-polluted sites

Entomologists at the University of California, Riverside have a "proof of concept" that selenium, a nonmetal chemical element, can disrupt the foraging behavior and survival of honey bees.

Selenium in very low concentrations is necessary for the normal development of insects — and humans — but becomes toxic at only slightly higher concentrations when it replaces sulfur in amino acids. In soils, particularly in Pacific Rim countries and near coal-fired power plants worldwide, it occurs most often in soluble forms, such as selenate.

Wondering what effect selenium concentrations in plants has on honey bees, John T. Trumble, a professor of entomology, and Kristen R. Hladun, his graduate student, performed controlled greenhouse experiments in which they documented the selenium amounts that three plant species — two kinds of mustards and one weedy radish plant — incorporate into their nectar and pollen after the plants had been irrigated with low to moderate levels of the trace mineral.

They then allowed honey bees to visit the plants. They found that the bees fed on food sources, such as flowers that contained selenium at even very high concentrations.

"Nature has not equipped bees to avoid selenium," Trumble said. "Unless the rates of concentrations of selenium were extremely high in our experiments, the bees did not appear to respond to its presence."

Two of the rates of irrigation water Trumble and Hladun tested had selenium concentrations — 0.5 and 0.7 parts per million — that were well below concentrations considered by the US government to be of concern.

"We found, however, that in weedy radish plants even these low rates produced selenium amounts of 60 parts per million in the nectar and 400 to 800 parts per million in the pollen," Hladun said. "But despite these high amounts, the bees would not avoid the selenium."

The researchers also found that bees that had been fed selenate in the lab were less responsive to sugar (as sucrose).

"The selenium interfered with their sucrose response," Hladun explained. "Such bees would be less likely to recruit bees to forage because they wouldn't be stimulated to communicate information about sucrose availability to the sister bees."

Trumble and Hladun also measured the mortality of forager bees that were fed selenium chronically (moderate selenium amounts over a few days). They found that these bees died at a significantly younger age.

Study results appear this month in PLoS ONE.

The researchers note that their work, performed in the laboratory, needs to be done next in the field because the bees' reduced response to sugar could diminish floral resources needed to support coworker bees and larvae in the field.

In preliminary studies they conducted in the field, the researchers found that some foragers leaving radish plants were carrying pollen with high concentrations of selenium. Further, they noted that plants with high concentrations of selenium were being visited by foragers just as frequently as were plants with no selenium, suggesting that the bees do not avoid feeding on selenium.

"The consequences of their inability to avoid selenium could be substantial," Trumble said. "We must emphasize that our data do not show that large losses of honey bees are currently occurring or that there is any relationship with Colony Collapse Disorder (CCD). Field studies need to be conducted to determine if honey bees collect enough selenium from contaminated plants to cause significant effects on learning, behavior and adult or larval survival."

The researchers already have received a three-year 480,000 grant from USDA-NIFA to take their research from the lab to the field. The grant, which will support Hladun's postdoctoral work at UCR, will allow the researchers also to investigate other elements, such as cadmium and lead, which have been found in urban honeybee hives.

"In our lab experiments, we focused on individual bees," said Hladun, who will graduate with a Ph.D. this summer. "But bees are social insects. In our future work, we plan also to focus on whole colony health."

Selenium occurs naturally in certain soils from shale deposits of prehistoric inland seas. Agricultural drainage dissolves selenium from these soils and causes the buildup of selenate. One of the worst cases of selenium pollution is the San Joaquin Valley in California, a major drainage site for many of the state's agricultural regions and an area that has reported honey bee loss due to CCD.

Trumble and Hladun were joined in the study by Ray R. Morton at UCR; and Brian H. Smith and Julie A. Mustard at Arizona State University, Tempe.

A US Environmental Protection Agency Science to Achieve Results (EPA-STAR) fellowship to Hladun supported the study.

The University of California, Riverside (www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment has exceeded 20,500 students. The campus will open a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual statewide economic impact of more than $1 billion. A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. UCR also has ISDN for radio interviews. To learn more, call (951) UCR-NEWS.

Iqbal Pittalwala | EurekAlert!
Further information:
http://www.ucr.edu

More articles from Life Sciences:

nachricht Researchers at the University of Freiburg use new method to investigate neural oscillations
14.02.2020 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Dragonflies move to the city
14.02.2020 | Technische Universität Braunschweig

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Skyrmions like it hot: Spin structures are controllable even at high temperatures

Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices

The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...

Im Focus: Making the internet more energy efficient through systemic optimization

Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.

Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.

Im Focus: New synthesis methods enhance 3D chemical space for drug discovery

After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.

"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.

Im Focus: Quantum fluctuations sustain the record superconductor

Superconductivity approaching room temperature may be possible in hydrogen-rich compounds at much lower pressures than previously expected

Reaching room-temperature superconductivity is one of the biggest dreams in physics. Its discovery would bring a technological revolution by providing...

Im Focus: New coronavirus module in SORMAS

HZI-developed app for disease control is expanded to stop the spread of the pathogen

At the end of December 2019, the first cases of pneumonia caused by a novel coronavirus were reported from the Chinese city of Wuhan. Since then, infections...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

Electric solid propellant -- can it take the heat?

14.02.2020 | Physics and Astronomy

Pitt study uncovers new electronic state of matter

14.02.2020 | Physics and Astronomy

Researchers observe quantum interferences in real-time using a new extreme ultra-violet light spectroscopy technique

14.02.2020 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>