Tag Archives: honey bees

Insecticide appears to reduce live bee sperm

A new study finds that a commonly used insecticide kills much of the sperm created by male drone honey bees, one reason why the bees are dwindling.

The class of insecticide called neonicotinoids didn’t kill the drones.

But bees that ate treated pollen produced 39 percent less live sperm than those that didn’t, according to a controlled experiment by Swiss researchers published in late July in the journal Proceedings of the Royal Society B.

It essentially acted as an accidental contraceptive on the drones, whose main job is to mate with the queen — but not one that prevented complete reproduction, just making it tougher, said Lars Straub, lead author of the study and a doctoral student and researcher at the University of Bern. Drones, which are the product of unfertilized eggs, don’t gather nectar or pollen and don’t sting; they die after mating.

Both the drones that ate insecticide-treated pollen and those not exposed to the chemicals produced about the same amount of sperm. The difference was clear when the researchers put the sperm under the microscope: The bee that didn’t have pesticide in its pollen produced on average 1.98 million living sperm, the one with neonicotinoids in its food about 1.2 million.

“There’s a reduction in sperm viability and the amount of living sperm, but that doesn’t mean there’s no living sperm at hand,” Straub said. The big question is there still enough of sperm that survive to do the job, he said. Queens generally have one mating flight and store sperm.

Study co-author Geoffrey Williams, a senior bee researcher at the University of Bern, said the team doesn’t know how the insecticides might be damaging the sperm, but it seems to be happening after they are produced.

This comes on top of a study published earlier this year in PLOS One that reported the high rate of U.S. honey bee colonies dying coincides with failures of queens. And the queen failure was linked to drones’ dead sperm.

“Queen failure is a big problem and this helps explain it,” said U.S. Department of Agriculture bee scientist Jeff Pettis, who wasn’t part of the neonicotinoid study but was lead author of the PLOS study on queen health. “It’s not the queens themselves, it’s the drones. It’s significant.”

There are many problems — mites, parasites, disease, pesticides and poor nutrition — that seem to combine to shrink the numbers of bees and other pollinators, Straub, Pettis and other scientists said. Pettis said he guesses that poor sperm health may account for about a third of the problem.

Neonicotinoid-maker Bayer Crop Science spokesman Jeffrey Donald said the firm’s scientists will review the study, but in general “artificial exposure to pesticides under lab conditions is not reflective of real-world experience.”

Another team of outside researchers, Jerry Bromenshenk and Colin Henderson at the University of Montana, praised the Straub study as careful and significant. But they said in an email there are still unanswered questions on how much this matters.

Court blocks use of insecticide believed to contribute to bees’ disappearance

A federal appeals court has blocked the use of a pesticide over concerns about its effect on honey bees, which have mysteriously disappeared across the country in recent years.

In her opinion, Judge Mary M. Schroeder, one of three judges who sit on the U.S. Court of Appeals for the Ninth Circuit panel, wrote that the Environmental Protection Agency had initially decided to conditionally approve the chemical — sulfoxaflor  — but ordered more studies to better understand the effects of the systemic insecticide on bees.

“A few months later, however, the EPA unconditionally registered the insecticides with certain mitigation measures and a lowering of the maximum application rate,” Schroeder wrote. “It did so without obtaining any further studies.”

“Given the precariousness of bee populations, leaving the EPA’s registration of sulfoxaflor in place risks more potential environmental harm than vacating it,” she added.

“Because the EPA’s decision to unconditionally register was based on flawed and limited data, we conclude that the unconditional approval was not supported by substantial evidence,” the court wrote.

The product, sold in the U.S. as Transform or Closer, must be pulled from store shelves by Oct. 18.

The judgment is a huge victory for environmentalists.

Sulfoxaflor belongs to a group of insecticides known as neonicotinoids (NEE-OH-NIC-DUH-NIDES), according to the Ninth Circuit ruling. Neonicotinoids are suspected of being among several factors that have contributed to the collapse of honey bee colonies throughout the U.S.

Bees, especially honeybees, are needed to pollinate crops, and they are considered essential to the U.S. food supply.

But a disorder has caused as much as one-third of the nation’s bees to disappear each winter since 2006. A 2013 report issued by the EPA and U.S. Department of Agriculture cited a parasitic mite, multiple viruses, bacteria, poor nutrition, genetics, habitat loss and pesticides as factors for the bees’ disappearance.

“We’re certainly extremely happy,” said Greg Loarie, an attorney with the group Earthjustice, which challenged the EPA’s approval of sulfoxaflor on behalf of groups in the beekeeping industry. “It means that sulfoxaflor comes off the market while the EPA does the work it should have done a long time ago.”

Loarie said the pesticide was used on cotton in southern states, but it had only been approved on an emergency basis for one crop in California.

Environmental groups petition president for new rules to protect honey bees

Environmental groups representing millions of Americans this week urged President Barack Obama to take action against neonicotinoid insecticides that are devastating honey bee and wild bee populations.

In a letter to the White House, the 11 groups called on the president to immediately suspend neonicotinoid use, take steps to curb the insecticides’ adverse impacts and to instruct his administration to close a legal loophole that allows insecticides sales before the chemicals are adequately assessed for safety.

The letter was sent three weeks after more than 100 businesses, many of them members of the American Sustainable Business Council and the Green America Business Network, sent a similar plea to the White House.

“We hope that you will prioritize action on this issue of vital importance to our food system, economy and environment and make saving bees a key piece of your legacy as president,” the letter stated.

Signers include Trip Van Noppen, president of Earthjustice; Peter Lehner, executive director of the Natural Resources Defense Council; Erich Pica, president of Friends of the Earth U.S., and nine other green CEOs.

Citing “a significant loss” of bees and other pollinators last summer, Obama created an interagency Pollinator Health Task Force to be co-chaired by the Environmental Protection Agency and the Agriculture Department. The president gave the task force 180 days to develop a national strategy.

The task force missed its December deadline and is expected to release a strategy paper in the coming weeks.

The letter charges that the EPA is unable “to properly regulate insecticides impacting bees” and notes the “EPA announced it will not release a regulatory decision on neonicotinoids before 2016.”

The letter urges the president to speed up the review of neonicotinoids and hasten the development of better tests for the insecticides’ effect on bees.

“If current rates of bee die-offs continue,” the letter stated, “it is unlikely that the beekeeping industry will survive EPA’s delayed timeline, putting our agricultural industry and our food supply at serious risk.”

Also, according to the letter, “EPA has allowed millions of acres of crop seeds treated with neonicotinoids to be planted annually with no registration of the pesticide-treated seeds and no enforcement against them in cases of misuse.”  Bees are critical for pollinating dozens of important American food crops and contribute nearly $20 billion to the U.S. economy annually.

Neonicotinoids, often applied to seeds before planting, are particularly dangerous for bees because they poison the whole plant, including the nectar and pollen which bees eat. At very high doses, they can kill bees directly; but they more commonly affect and impair bees’ ability to breed, forage, fight disease and survive the winter, scientists say. Yet a recent EPA analysis found that neonicotinoid treatment on soybean seeds offers little or no economic benefit to soy producers.

The U.S. Fish and Wildlife Service will phase out use of neonics in wildlife refuges by 2016. Meanwhile, the European Union has a two-year ban on the most widely used neonics.