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.
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.
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
Nathalie Matter | Universität Bern
New technique reveals details of forest fire recovery
17.05.2018 | DOE/Brookhaven National Laboratory
Mixed forests: ecologically and economically superior
09.05.2018 | Technische Universität München
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...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
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...
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...
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...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology