Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study finds higher pathogen loads in collapsed honeybee colonies

18.08.2009
Honeybees in colonies affected by colony collapse disorder (CCD) have higher levels of pathogens and are co-infected with a greater number of pathogens than their non-CCD counterparts, but no individual pathogen can be singled out as the cause of CCD, according to a study by an international team of researchers.

The researchers, who represented Penn State's College of Agricultural Sciences, University of Liege, Gembloux Agricultural University, North Carolina State University and the U.S. Department of Agriculture's Agricultural Research Service (ARS), collected samples of adult bees, wax comb, pollen and brood – developing larvae – from 91 colonies in 13 apiaries in Florida and California and quantified more than 200 variables, including the presence of parasites such as varroa and tracheal mites; infection by bacteria, viruses and fungi; pesticide levels; nutritional factors; and bee physiology. No single factor was found consistently only in those colonies suffering from CCD.

The study's findings, which were published in the online journal PLoS ONE, illustrate the complexity of solving the CCD problem, according to lead author and Penn State entomologist Dennis vanEngelsdorp. "Our results suggest that this condition may be contagious or the result of exposure to a common risk factor that impairs the bees' immune systems, making them more susceptible to pathogens," said vanEngelsdorp, who also is acting state apiarist for the Pennsylvania Department of Agriculture.

VanEngelsdorp noted that higher pathogen loads are likely to have caused CCD symptoms, but what causes the bees to become infected with so many pathogens is still not known. "Although pathogens seem likely to play a critical role in CCD, that role may be secondary, much like AIDS patients die from secondary diseases," he added.

No one of the screened pathogens had a higher prevalence in colonies that had CCD. There also was no significant difference in the prevalence nor in the total load of varroa or tracheal mites and Nosema, a protozoan that causes disease in bees.

But overall, CCD colonies were co-infected with a greater number of pathogens -- viruses, bacteria and microparasites such as Nosema. For instance, 55 percent of CCD colonies were infected with three or more viruses compared to 28 percent of non-CCD colonies.

The researchers also found detectable levels of residues from 50 different pesticides in all of the sampled colonies, but there was no association between increased pesticide levels and CCD.

In fact, the pyrethroid insecticide Esfenvalerate -- used for a wide variety of pests such as moths, flies, beetles and other insects on vegetable, fruit and nut crops -- was more prevalent in the wax in non-CCD colonies, being found in 32 percent of non-CCD colonies compared to 5 percent of the CCD colonies.

Coumaphos, which is used to treat varroa mites in honeybees, also was found in higher levels in non-CCD colonies.

Entomologist Jeff Pettis with the ARS Bee Research Laboratory in Beltsville, Md., said the study suggests that future research should focus on monitoring parasite, pathogen and pesticide loads, as well as potential interactions among pesticide and pathogen loads. "While the study's results don't indicate a specific cause of CCD, the results do help scientists narrow the direction of future CCD research by showing that some possible causes are less likely," said Pettis.

Study co-authors from Penn State are included Chris Mullin, professor of entomology; Maryann Frazier, senior extension associate in entomology; Jim Frazier, professor of entomology; and Diana Cox-Foster, professor of entomology and Robyn Underwood.

Other researchers included Jay D. Evans and Yanping Chen, ARS; Claude Saegerman, University of Liege; Eric Haubruge and Bach Kim Nguyen, Gembloux Agricultural University, Belgium and David R. Tarpy, North Carolina State University.

Chuck Gill | EurekAlert!
Further information:
http://www.psu.edu

More articles from Agricultural and Forestry Science:

nachricht New technique reveals details of forest fire recovery
17.05.2018 | DOE/Brookhaven National Laboratory

nachricht Mixed forests: ecologically and economically superior
09.05.2018 | Technische Universität München

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: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>