Quantcast
Environmental News for a Healthier Planet and Life

This Popular Insecticide Is Lowering Sperm Count in Honey Bees by 40%

Science
Bees are dying in unsustainable numbers, and this latest study is further evidence that an extremely common pesticide might be behind it. / Flickr

Neonicotinoids, a common and highly controversial class of insecticides linked to catastrophic bee deaths, could be significantly lowering the sperm count of male drone honey bees and cutting their life span by a third, Swiss researchers found.

Researchers from the Institute of Bee Health at the University of Bern, Switzerland discovered that male drone honeybees that ate pollen treated with two popular "neonics"—thiamethoxam and clothianidin—produced nearly 40 percent less sperm than those that did not.


When sperm from both sets of drones were put under the microscope, the ones treated with neonics produced 1.2 million living sperm on average while the control group produced 1.98 million. The authors said that the insecticides "can serve as inadvertent insect contraceptives." A drone's main role is to mate with the queen bee.

"While no significant effects were observed for male teneral (newly emerged adult) body mass and sperm quantity, the data clearly showed reduced drone lifespan, as well as reduced sperm viability (percentage living versus dead) and living sperm quantity by 39 percent," the report states.

The results showed, for the first time, that neonicotinoids can negatively affect male insect reproductive capacity. The authors said their study might explain the declining population of wild insect pollinators as well as queen bee failure in managed fields.

"Because queen survival and productivity are intimately connected to successful mating, any influence on sperm quality may have profound consequences for the fitness of the queen, as well as the entire colony," the report said.

Geoffrey Williams, the study's co-author and University of Bernsenior bee researcher, told the Associated Press he does not know how exactly the insecticides might be damaging the sperm, but it seems to be happening after they are produced.

In another alarming discovery, the researchers found that 32 percent of the neonic-exposed drones died before reaching sexual maturity, compared to 17 percent of the unexposed controls. The average lifespan of insecticide drones was around 15 days, significantly lower than controls's lifespan of 22 days.

"This could have severe consequences for colony fitness, as well as reduce overall genetic variation within honeybee populations," the authors said.

The study was published today in the British journal Proceedings of the Royal Society B.

As the Associated Press pointed out, the worrisome population decline of pollinators can come down to a combination of many culprits, such as mites, parasites, disease, pesticides and poor nutrition. However, U.S. Department of Agriculture bee scientist Jeff Pettis, who was not part of the neonicotinoid study, suggested that poor sperm health may account for about a third of the growing crisis.

Neonicotinoid-maker Bayer Crop Science spokesman Jeffrey Donald told the AP that the company will review the study, but in general "artificial exposure to pesticides under lab conditions is not reflective of real-world experience."

Peter Campbell from Syngenta, the maker of thiamethoxam, told the Guardian that the study was interesting but added, "given the multiple mating of honeybee queens it is unclear what the consequences of a reduction in sperm quality would actually have on queen fecundity."

This latest study adds to the mounting scientific evidence that neonicotinoids—which are used on many crops in the U.S.—are harmful to pollinators. As Friends of the Earth wrote, bees are crucial to food production but are dying at unsustainable rates, with an unprecedented average of 30 to 40 percent loss of all honeybee colonies each year.

An investigation by the environmental group, Buzz Kill: How the Pesticide Industry is Clipping the Wings of Bee Protection Efforts Across the U.S., has found that the pesticide industry is stifling urgently needed reforms that would help these essential pollinators survive and rebuild their numbers.

EcoWatch Daily Newsletter

Pexels

By SaVanna Shoemaker, MS, RDN, LD

An Important Note

No supplement, diet, or lifestyle modification — aside from social distancing and practicing proper hygiene ⁠— can protect you from developing COVID-19.

The strategies outlined below may boost your immune health, but they don't protect specifically against COVID-19.

Read More Show Less
Pexels

By Zak Smith

It is pretty amazing that in this moment when the COVID-19 outbreak has much of the country holed up in their homes binging Netflix, the most watched show in America over the last few weeks has been focused on wildlife trade — which scientists believe is the source of the COVID-19 pandemic. Make no mistake: Tiger King: Murder, Mayhem and Madness is about wildlife trade and other aspects of wildlife exploitation, just as surely as the appearance of Ebola, SARS, MERS, avian flu and probably COVID-19 in humans is a result of wildlife exploitation. As a conservationist, this is one of the things I've been thinking about while watching Tiger King. Here are five more:

Read More Show Less
Sponsored
Pexels

By Hector Chapa

With the coronavirus pandemic quickly spreading, U.S. health officials have changed their advice on face masks and now recommend people wear cloth masks in public areas where social distancing can be difficult, such as grocery stores.

But can these masks be effective?

Read More Show Less
Jörg Carstensen / picture alliance via Getty Images

By Carey Gillam

Bayer AG is reneging on negotiated settlements with several U.S. law firms representing thousands of plaintiffs who claim exposure to Monsanto's Roundup herbicides caused them to develop non-Hodgkin lymphoma, sources involved in the litigation said on Friday.

Read More Show Less
Tom Werner / DigitalVision / Getty Images

By Jillian Kubala, MS, RD

With many schools now closed due to the current COVID-19 outbreak, you may be looking for activities to keep your children active, engaged, and entertained.

Although numerous activities can keep kids busy, cooking is one of the best choices, as it's both fun and educational.

Read More Show Less