Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Two neonicotinoid insecticides may have inadvertent contraceptive effects on male honey bees

27.07.2016

Male honey bees, called drones, can be affected by two neonicotinoid insecticides by reducing male honey bee lifespan and number of living sperm. Both insecticides are currently partially banned in Europe. Researchers from Bern, Switzerland, together with partners from Thailand and Germany, call for more thorough environmental risk assessments of these neonicotinoids.

In recent years, beekeepers have struggled to maintain healthy honey bee colonies throughout the northern hemisphere. In the first study to investigate the effects of neonicotinoids on drones, and one of the first to study the effects of these agricultural chemicals on males in general, an international research team led by the University of Bern and Agroscope has found that two neonicotinoids may inadvertently reduce drone lifespan and number of living sperm.


A newly emerged male honey bee, known as a drone, on a wax bee frame.

© Geoffrey Williams, University of Bern / Agroscope.


Fluorescence microscopy revealing living (stained bluish-green) and dead (stained red) male honey bee sperm.

© Lars Straub, University of Bern

Because queen survival and queen productivity are intimately connected to successful mating with males, any influence on sperm quality may have profound consequences for the health of the queen, as well as the entire colony. In light of recent beekeeper surveys that identified poor queen health as an important reason for honey bee colony losses, this study further strengthens calls for more thorough environmental risk assessments of these insecticides, as well as other crop protection products, to protect bees and other beneficial organisms.

‘We know multiple stressors can affect honey bee health, including parasites and poor nutrition. It is possible that agricultural chemicals may also play an important role’, says senior author Geoff Williams of the University of Bern and Agroscope. In 2013, the European Union and Switzerland took a precautionary approach by partially restricting the application of the widely used neonicotinoid insecticides thiamethoxam, clothianidin, and imidacloprid, with the mandate to perform further environmental risk assessments.

A new inter-governmental review is currently taking place. Previous research suggests that these chemicals cause both lethal and sub-lethal effects on honey bee females from exposure, but nothing is known about how they may affect males of the species.

A research team from the institutes of bee health and veterinary public health at the University of Bern (Switzerland) and Agroscope at the Swiss Confederation (Switzerland), alongside collaborators from Chiang Mai University and Mae Fah Luang University (Thailand) and the University of Koblenz-Landau (Germany) recently demonstrated in an article in the prestigious scientific journal Proceedings of the Royal Society of London B: Biological Sciences that male honey bees, also called drones, are vulnerable to the neonicotinoids thiamethoxam and clothianidin.

Reduced longevity and sperm quality

The study showed that males maintained in the laboratory after colony-level exposure had a shorter lifespan and produced fewer living sperm. This could have important consequences for colonies because queens, which are essential to colony functioning, must be properly inseminated with healthy sperm from multiple males. Factors affecting the health of drones could therefore have profound consequences not just for the queen, but for the entire colony, as replacement of poorly mated queens is resource intensive and not without risks.

‘Most neonicotinoid studies that employ honey bees have focused on workers, which are typically the non-reproductive females of the colony. Male honey bees have really been neglected by honey bee health scientists; while not surprising, these results may turn a few heads’, says lead author and doctoral student Lars Straub from the University of Bern. Co-author Peter Neumann from Bern states ‘these results, coupled with the importance of males to honey bee reproduction, highlight the need for stringent environmental risk assessments of agricultural chemicals to protect biodiversity and ecosystem functioning.’

Bees, pollination, and honey

Honey bees, like all insect pollinators, provide crucial ecosystem and economic services. Annually in Europe and North America, millions of honey bee colonies produce honey and contribute to the pollination of a range of agricultural crops – from carrots to almonds to oilseed rape – that is valued at billions of Euros.

Publication details:

Straub, L., Villamar-Bouza, L., Bruckner, S., Chantawannakul, P., Gauthier, L., Khongphinitbunjong, K., Retschnig, G., Troxler, A., Vidondo, B., Neumann, P., Williams, G.R. 2016. Neonicotinoid insecticides can serve as inadvertent insect contraceptives. Proc. R. Soc. B 20160506 doi: 10.1098/rspb.2016.0506. Available at: http://dx.doi.org/10.1098/rspb.2016.0506

Weitere Informationen:

http://www.unibe.ch/news/media_news/media_relations_e/media_releases/2016_e/medi...

Nathalie Matter | Universität Bern

More articles from Agricultural and Forestry Science:

nachricht Researchers discover natural product that could lead to new class of commercial herbicide
16.07.2018 | UCLA Samueli School of Engineering

nachricht Advance warning system via cell phone app: Avoiding extreme weather damage in agriculture
12.07.2018 | Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>