Light Therapy Can Protect Bees From Pesticide Poisoning

UPI Science News     November 15, 2016

Light therapy protects bees from the harms of pesticide exposure, new research shows.
Photo by Ismael Mohamad/UPI | License Photo

LONDON, Nov. 15 (UPI) --
 Light therapy offers protection to honey bees exposed to neonicotinoid pesticides, according to new research from University College London.

In a new study, scientists at UCL studied the effects of pesticides and light therapy on commercial honey bee hives. Two of the four studied hives were exposed to a neonicotinoid pesticide called Imidacloprid for 10 days. One of the two exposed haves were also treated with twice-daily 15-minute doses of near infrared light.

Previous research has proven pesticide exposure undermines honey bees' ability to produce ATP, the energy necessary for healthy cellular function.

In the experiments, pesticide-poisoned bees not treated to light therapy showed drastically reduced ATP levels. They also showed symptoms of diminished mobility. Bees poisoned and treated with near infrared light were more mobile and boasted better survival rates.

One of the two control groups was treated with light even though they hadn't been exposed to pesticides. The light-treated group had higher survival rates than the control group that was neither poisoned nor treated.

"Long-wavelength light treatments have been shown in other studies to reduce mitochondrial degeneration which results from aging processes," Glen Jeffery, a researcher with the UCL Institute of Ophthalmology, said in a news release. "It's beneficial even for bees that aren't affected by pesticides, so light therapy can be an effective means of preventing loss of life in case a colony becomes exposed to neonicotinoids. It's win-win,"

The new findings -- detailed in the journal PLOS ONE -- suggest light therapy works best as a preventative method, but can also trigger recovery in bees if doses begin within two days of pesticide exposure.

"We found that by shining deep red light on the bee which had been affected by the toxic pesticides that they could recover, as it improved mitochondrial and visual function, and enabled them to move around and feed again," added Michael Powner, a former UCL researcher now working at City, University of London.

Bees are now one of several animals shown to benefit from regular exposure to near infrared light.

"When a nerve cell is using more energy than other cells, or is challenged because of a lack of energy, red light therapy can give it a boost by improving mitochondrial function," Jeffery explained. "Essentially, it recharges the cell's batteries."

http://www.upi.com/Science_News/2016/11/15/Light-therapy-could-cure-pesticide-poisoned-bees/9591479240027/

Millions of Honeybees Killed by Zika Spraying in SC County

CNN    By Sandee LaMotte     September 2, 2016 

(CNN) The pictures are heartbreaking: Millions of honeybees lie dead after being sprayed with an insecticide targeting Zika-carrying mosquitoes.

"On Saturday, it was total energy, millions of bees foraging, pollinating, making honey for winter," beekeeper Juanita Stanley said. "Today, it stinks of death. Maggots and other insects are feeding on the honey and the baby bees who are still in the hives. It's heartbreaking." 

Stanley, co-owner of Flowertown Bee Farm and Supply in Summerville, South Carolina, said she lost 46 beehives -- more than 3 million bees -- in mere minutes after the spraying began Sunday morning. 

Juanita Stanley says she lost more than 3 million bees."Those that didn't die immediately were poisoned trying to drag out the dead," Stanley said. "Now, I'm going to have to destroy my hives, the honey, all my equipment. It's all contaminated." 

Stanley said Summerville Fire Capt. Andrew Macke, who keeps bees as a hobby, also lost thousands of bees. She said neither of them had protected their hives because they didn't know about the aerial spraying. 

"Andrew has two hives," Stanley said. "He didn't know they were going to spray. His wife called him. His bees are at their porch right by their home, and she saw dead bees everywhere." 

It's a tragedy that could be repeated across the country as cases of Zika continue to rise and local mosquito control districts struggle to protect their residents and ease local fears. 

The spray fell from the skies between 6:30 and 8:30 a.m. Sunday. It was the first aerial spraying in 14 years, according to Dorchester County Administrator Jason Ward, part of the county's efforts to combat Zika after four local residents were diagnosed with the virus. 

"We chose Sunday morning because few people would be out and about that early on a weekend," Ward said. "To protect the bees, you don't want to spray after the sun has been up more two hours, so we scheduled it early."

The county used a product called Trumpet, which contains the pesticide naled, recommended by the Environmental Protection Agency and the Centers for Disease Control and Prevention for control of adult Aedes aegypti, the mosquito that transmits Zika. 

According to the manufacturer's label (PDF), Trumpet is "highly toxic to bees exposed to direct treatment on blooming crops or weeds. To minimize hazard to bees, it is recommended that the product is not applied more than two hours after sunrise or two hours before sunset, limiting application to times when bees are least active." 

"We followed that recommendation," said Ward, "which is also the policy laid out by the state, using a pesticide the state has approved for use." 

Ward says the county also notified residents of the spraying by posting a notice on its website at 9 a.m. Friday, two days before the spraying. He added that it alerted beekeepers who were on the local mosquito control registry by phone or email, a common practice before truck spraying. 

The loss of her "honey girls" is devastating, says Juanita Stanley."That's true when they sprayed by trucks; they told me in advance, and we talked about it so I could protect my bees," Stanley said. "But nobody called me about the aerial spraying; nobody told me at all." 

Stanley said she "would have been screaming and pleading on their doorstep if they had." 

"'Do it at night when bees are done foraging,' I would have told them," she added, breaking into tears. "But they sprayed at 8 a.m. Sunday, and all of my bees were out, doing their work by then."

Macke was also not informed, Ward said, because he, like many hobby beekeepers, is not on the local mosquito control registry. 

"We are obviously saddened by the fact people have lost their hives, and we have gone back and looked at our procedures," Ward said. "We will now give up to five days of advance notice, and we have expanded our list to include more local beekeepers." 

Stanley says she doesn't think there was malice involved, but that doesn't make the loss of her "honey girls" any less painful. 

"This wasn't about the honey," she said. "It was about raising bees and selling them to other people, and spreading the honey girls out there into the world. Now, I can't help anyone anymore, because all of them are dead."

http://www.cnn.com/2016/09/01/health/zika-spraying-honeybees/index.html

 

RELATED ARTICLE: The Washington Post: http://www.msn.com/en-us/news/us/%e2%80%98like-it%e2%80%99s-been-nuked-millions-of-bees-dead-after-south-carolina-sprays-for-zika-mosquitoes/ar-AAim4q3?li=BBnbcA1&srcref=rss&ocid=iehrs

 

Bees 'Dumb Down' After Ingesting Tiny Doses of the Pesticide Chlorpyrifos

Phys.org   Provided by: University of Otago  March 1, 2016

Honeybees suffer severe learning and memory deficits after ingesting very small doses of the pesticide chlorpyrifos, potentially threatening their success and survival, new research from New Zealand's University of Otago research suggests.

In their study, researchers from the Departments of Zoology and Chemistry collected bees from 51 hives across 17 locations in the province of Otago in Southern New Zealand and measured their chlorpyrifos levels. They detected low levels of pesticide in bees at three of the 17 sites and in six of the 51 hives they examined.

Detecting chlorpyrifos was not a surprise. In 2013, Associate Professor Kim Hageman and her team from Otago's Department of Chemistry showed that chlorpyrifos was detectable in air, water, and plant samples even in non-sprayed areas of the country, because this pesticide has a high ability to volatilise and travel great distances.

In the laboratory they then fed other bees with similar amounts of the pesticide, which is used around the world to protect food crops against insects and mites, and put them through learning performance tests.

Study lead author Dr Elodie Urlacher says they found that chlorpyrifos-fed bees had worse odour-learning abilities and also recalled odours more poorly later, even though the dose they ingested is considered to be "safe".

"For example, the dosed bees were less likely to respond specifically to an odour that was previously rewarded. As honeybees rely on such memory mechanisms to target flowers, chlorpyrifos exposure may be stunting their effectiveness as nectar foragers and pollinators," Dr Urlacher says.

The study identified the threshold dose for sub-lethal effects of chlorpyrifos on odour-learning and recall as 50 picograms of chlorpyrifos ingested per bee, she says.

"This amount is thousands of times lower than the lethal dose of pure chlorpyrifos, which is around 100 billionths of a gram. Also, it is in the low range of the levels we measured in bees in the field."

The current study is the first to establish the threshold at which a pesticide has an effect on memory specificity in bees while also measuring doses in bee populations in the field, she says.

"Our findings raise some challenging questions about regulating this pesticide's use. It's now clear that it is not just the lethal effects on  that need to be taken into account, but also the serious sub-lethal ones at minute doses," Dr Urlacher says.

Explore further: Diet affects pesticide resistance in honey bees

More information: Elodie Urlacher et al. Measurements of Chlorpyrifos Levels in Forager Bees and Comparison with Levels that Disrupt Honey Bee Odor-Mediated Learning Under Laboratory Conditions, Journal of Chemical Ecology (2016). DOI: 10.1007/s10886-016-0672-4 

Read more at: http://phys.org/news/2016-03-bees-dumb-ingesting-tiny-doses.html#jCp

Bees Threatened By A Common Pesticide, EPA Finds

Los Angeles Times    By Geoffrey Mohan   January 6, 2016

A queen bee is seen in the center of a hive. (Rich Pedroncelli / Associated Press)

The U.S. Environmental Protection Agency said Wednesday that imidacloprid, a nicotine-imitating chemical found in at least 188 farm and household products in California, “potentially poses risk to hives when the pesticide comes in contact with certain crops that attract pollinators.”

The EPA's decision was prompted by increasing concern that the chemicals might be contributing to the sudden collapse of commercial honey bee colonies over the last decade. Those bees pollinate crucial food crops and contribute about $14 billion in value to the agricultural economy nationwide.

This is the first of four risk assessments conducted by the EPA on the class of pesticides known as neonicotinoids. The rest are slated for completion by the end of the year, after which the agency could tighten controls over the insecticides.

“Clearly, as a result of this, there might be more restrictions coming,” said Charlotte Fadipe, spokeswoman for the California Department of Pesticide Regulation.

California's almond crop, valued at about $7 billion, is completely dependent on nearly 1 million commercial hives brought in to pollinate about 870,000 acres of trees. Other crops that depend strongly on commercial honeybee colonies include oranges and grapefruits, blueberries, cherries, alfalfa, apples, avocados, cucumbers, onions, cantaloupe, cranberries, pumpkins and sunflowers.

The single biggest user, however, was the predominantly urban structural pest control industry, which applied nearly 37 tons, according to the agency.

Several studies have linked high levels of neonicotinoids to decreased foraging, failures of queen bees, breakdowns in hive communication and other colony-threatening phenomena. Last year, however, a study suggested that exposure to levels of the pesticide expected on most farms would pose no significant negative effects on bee colonies.

Many factors have been blamed for the bee die-offs: exposure to multiple pesticides, poor hive management practices and natural pathogens such as mites and viruses. Although full-scale colony collapses have largely abated over the last several years, bees are continuing to die at a higher-than-normal rate. The USDA last year reported winter colony losses of about 23%, based on a survey of beekeepers. A winter decline of about 19% is considered normal.

The EPA and its research partners weighed evidence from several hundred scientific studies before concluding that chemical traces of more than 25 parts per billion on plants probably will harm bees.

Last year, the agency halted approval of any new outdoor uses of neonicotinoid pesticides until it completes a full risk assessment. It also has proposed banning use of any pesticide found to be toxic to bees while crops are in bloom and commercial colonies are present.

Bayer CropScience said the EPA's assessment “appears to overestimate the potential for harmful exposures in certain crops, such as citrus and cotton, while ignoring the important benefits these products provide and management practices to protect bees.”

The company added that it hoped the agency further considers “the best available science, as well as a proper understanding of modern pest management practices.”

Pesticide industry advocates said it was premature to talk about a ban on the chemical.

“I think there's a lot more work to be done, but we're pretty confident that the product is ultimately going to be found safe either as registered or with potentially any mitigation measures that need to be added,” said Renee Pinel, president of the Western Plant Health Assn. in Sacramento.

The Center for Biological Diversity, an environmental advocacy group, chided EPA for not broadening its investigation beyond the honey bee, to the more than 4,000 wild bee species, and to other pollinators, including butterflies and bats.

“You can't claim to do a ‘pollinator risk assessment' and really only look at one pollinator, the honeybee,” said Lori Ann Burd, environmental health director of the group. “That's not only cheating on the purpose of this work but also cheating the native bees, birds, butterflies and other species threatened by this pesticide.”

Two other groups, the Center for Food Safety and the Pesticide Action Network, filed a lawsuit Wednesday against EPA, seeking tighter regulation of seeds coated in neonicotinoids.

Jeff Anderson, a Minnesota beekeeper and plaintiff in the suit, said EPA “didn't say anything of substance” and did not commit to changing any regulations on neonicotinoids.

Anderson rents hives to California almond growers, then to growers of cherries, apples and blueberries, before bringing them back to Minnesota for honey production in the late spring and summer. There, he has lost as much as 50% of his 3,000 bees, at a time when coated seeds are planted and cultivated.

Dust from the seeds can spread the pesticide, which also is taken up into the plant, and can be detected in its nectar and pollen, said Scott Black, executive director of the Xerces Society, which pushes for conservation of insects.

“You really can't look at total risk to pollinators without looking at seed coating, and you really can't look at total risk to pollinators without looking at the 4,000 or so other species,” Black said.

http://www.latimes.com/business/la-fi-pesticide-bees-20160106-story.html

Bee Expert: USDA Punished Me For Research on Pesticides

MPR News   By Dan Gunderson   October 28, 2015

A top federal bee scientist from South Dakota says he's being punished for publicizing work on pesticides and pollinators.

Jonathan Lundgren's research found bees and monarch butterflies can be harmed by a widely used class of insecticides. In a whistleblower case filed Wednesday, the United States Agriculture Department entomologist alleges he faced retaliation because of his research.

"Once he started publishing this work, he went from golden boy to pariah, and that's what this case is about," said Jeff Ruch, executive director of the Washington, D.C.-based group Public Employees for Environmental Responsibility, which is representing Lundgren in his complaint to a federal whistleblower protection board.

Lundgren's 11-year career at USDA appeared stellar. He had excellent performance reviews. USDA even named him its Outstanding Early Career Research Scientist in 2011.

The complaint says that all changed when Lundgren began to study how neonicotinoid insecticides affect bees and other beneficial insects. His research and work travel fell under intense scrutiny and he was suspended for violating agency protocols.

Ruch contends that pressure from the pesticide industry has led USDA to stifle scientists like Lundgren. He had no evidence, but said the complaint will let attorneys seek information and interview USDA officials about the Lundgren case. He believes that work will prove USDA targeted Lundgren because of his neonicotinoid research.

Those pesticides are among the most widely used in the world and are used heavily on farm fields and in backyards.

But they're under fire for contributing to an international decline in bee populations. Neonicotinoid insecticides are systemic. Plants take up the chemical along with nutrients. It's in the leaves, flowers and pollen.

Lundgren claims his trouble started in early 2014 when he began to talk publicly about negative effects of neonicotinoids. He reviewed a study by the Center for Food Safety. The study was critical of overuse of neonicotinoids on crops. He also did media interviews about the topic.

Lundgren declined an on-the-record interview, saying he fears additional retaliation. He alleges a USDA official asked him to stop talking publicly about the pesticide.

A USDA spokesperson said that while the agency can't discuss individual cases it takes scientific integrity seriously. "We fully review allegations of wrong-doing and make the results of those reviews available to the public online. USDA, he added, has "procedures for staff to report any perceived interference with their work, seek resolution, and receive protection from recourse for doing so."

In September 2014, Lundgren filed an internal complaint alleging USDA was violating its scientific integrity policy by retaliating because of the content of his research.

"Within one week of these late-March press interviews and the release of the CFS study, improper reprisal, interference and hindrance of my research and career began in earnest," according to the internal complaint.

He said "national program staff" removed his research objective examining pesticide risk. Instead, the goals focused on "strategies to improve diversity and health of beneficial insects," a change he said makes examining pesticide risk risky since it would "no longer be officially supported by USDA."

USDA found his scientific integrity complaint was without merit. Lundgren appealed. The appeal is awaiting a USDA response.

Lundgren was suspended in October 2014 for three days after USDA investigators found emails among his research staff which included off-color jokes.

Entomologist Jonathan Lundgren examined a pollinator food plot with colleague Christina Mogren, a postdoctoral researcher, near Brookings, S.D., in July. Dan Gunderson | MPR News file

Ruch says no employees had complained about the emails and employees in Lundgren's lab wrote letters of support for their boss.

"This is a scientist who has many prestigious journals publishing his work. He is invited to make presentations both nationally and internationally," Ruch said. "If it was not the sensitive nature of his research this would be somebody they would be promoting, not on the verge of terminating."

Earlier this year Lundgren again ran afoul of USDA supervisors.

He wrote a paper on research that showed neonicotinoid insecticides killed or stunted growth of monarch butterfly larvae. Monarch populations have plummeted in recent years because of habitat loss. Lundgren's research showed milkweed plants growing near farm fields treated with the insecticide could harm monarch larvae.

He believed he had permission from USDA to publish the paper.

Lundgren was interviewed about his research for an MPR News story in February. The whistleblower complaint says that interview prompted a sharp response two weeks later from his supervisor in Brookings, S.D.

Lundgren says he was told USDA considered his research "sensitive" and requiring additional layers of approval. The paper was published in March.

In early March, Lundgren traveled to speak at a National Academy of Sciences gathering and to an agricultural group in Pennsylvania.

While he was traveling to the meetings, he received a message saying his travel was not approved because he failed to get a required supervisor's signature.

He was considered absent without leave and ordered to return immediately to South Dakota.

Ruch said the travel paperwork mistake is one often overlooked at USDA.

In early August USDA area supervisor John McMurtry wrote to Lundgren imposing a 14-day unpaid suspension for "blatant disregard of Agency rules and regulations."

McMurtry said Lundgren's behavior "suggests a low potential for rehabilitation."

According to an internal USDA document, Lundgren was told that "additional misconduct will not be tolerated and may result in disciplinary action up to and including your removal from the Federal service."

Ruch says that that threat led to the whistleblower complaint to the Federal Merit Systems Protection Board.

Ruch's group says the charges are "patently exaggerated, and the punishment is disproportionate to the alleged wrongdoing." Ruch also believes the case will show the conflicts were about the research, not rule violations.

"There were repeated expressions about the sensitivity of the subject matter that made it clear there was concern that went much higher than (USDA's) Agricultural Research Service office in South Dakota," he said. "We believe that there was communication among high level managers of USDA that predetermined what they were going to do."

LISTEN and Read at: http://www.mprnews.org/story/2015/10/28/bee-expert

Related: http://www.panna.org/blog/usda-suppressing-bee-science

Bee Losses. Pesticides or Habitat Loss? EPA Uncertain

CATCH THE BUZZ    By Kim Flottum  November 26, 2014

By Paul Bedard, in Washington Secrets.

Over 100 scientists worldwide, citing 800 studies, are demanding that the Obama administration follow Europe’s lead and put a moratorium on the use of a new-style pesticide blamed for the deaths of 30 percent of American honeybees every year.

In a letter to the EPA and Agriculture Department, the scientists said there is overwhelming evidence from 800 studies that the pesticide family called neonicotinoids are to blame for the substantial declines in honeybees, bumblebees and butterflies, all pollinators needed to help farmers produce billions of dollars worth of food every year.

“The 108 signers of this letter therefore urge you to take immediate action to protect bees and other pollinators, particularly from pesticides known to be harmful,” said the letter provided to Secrets.

Despite actions by the European Union and some U.S. cities and states to limit use of the “neonics,” the administration is taking a go-slow approach.

“We share concerns about the decrease in the honey bee population, without question,” EPA Director Gina McCarthy told Secrets during a recent media roundtable sponsored by the Christian Science Monitor.

She seemed to blame the decade-long die-off of bees on development. “There are a number of factors that need to be considered, a lot of it could be attributable to habitat loss, and much of it might be,” she said.

McCarthy added that the EPA, under President Obama’s direction, is looking into the issue and holding listening sessions around the nation, but is not ready to act until the agency has thoroughly studied the science of the pesticides.

“There is no resolution off the table,” she said. But, she added, the agency won’t be “quick to judge.”

The scientists, from schools such as Harvard University and University of California, and as far away as Germany, however, said the issue has already been studied. They cited a June 2014 worldwide review of 800 studies by 29 independent researches that blamed the bee kills onneonics, which are typically treated on seeds and can stay in the ground for years.

They are blamed for disrupting the homing ability of bees heading back to the hive, a key issue on Colony Collapse Disorder.

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com

Read at... http://live.ezezine.com/ezine/archives/1636/1636-2014.11.26.11.32.archive.html

Find EVERY BUZZ Archive at www.BeeCulture.com

California Stung by Lawsuit to Protect Bees

Pesticide Action Network    By Paul Towers    July 8, 2014

They’re in our garden plants, sprayed on orchards throughout the state, and used as seed coatings on commodity crops in California and across the country. After five years of review, California officials have not only failed to complete an evaluation of neonicotinoid pesticides (neonics), they continue to allow more and more of these bee-harming chemicals into the market.

Fed up with the years of hand-sitting, PAN and our partners brought the state and pesticide manufacturers to court today.

PAN and partners at Beyond Pesticides and Center for Food Safety warned the California Department of Pesticide Regulation (DPR) in February that they were violating the law by approving new neonics. They ignored our concerns, despite a mounting body of evidence showing harms to bees. We reminded them again in June, only to have the agency approve more pollinator-toxic products.

Our attorney Greg Loarie at Earthjustice summed up our decision to bring DPR to court pretty well:

“It’s past time for DPR to fix its broken evaluation system and protect our bees and our agricultural economy. It obviously will take legal action to accomplish this.”

Despite five years of review, the agency has yet to finish an evaluation of any neonic product. And over the past couple of years, state officials have either allowed significantly expanded use of neonics or brought new products to market in at least fifteen separate instances.

As I recently noted, this lack of action persists even as independent scientists from around the globe concluded — after review of over 800 studies — that it’s time for international action to restrict neonics and protect bees.

Beekeepers are weighing in too, demanding accountability. Todd Bebb, vice president of the Santa Barbara Beekeepers Association and sponsor of bee-protective legislation in California, said:

“Bees are in trouble unless California officials do their part. Our food system, including farms and backyard gardens, rests on bees and beekeepers for continued pollination and support.”

While beekeepers and food and farming groups duke it out with state officials and pesticide manufacturers in court, the California legislature continues to move ahead with a bill that would force DPR to complete its evaluation of neonics on a specific timeline. That bill will be taken up after the July recess.

Local governments in Oregon and Washington have stepped up with bee-protective policies in recent months. And news out of Canada just this week is that at least one province is considering a licensing system to better regulate widespread use of the products.

With legal pressure building on California policymakers and related legislation on the horizon, it's time for the Golden State to get serious about protecting bees from harmful pesticides too.

Read at... http://www.panna.org/blog/california-stung-lawsuit-protect-bees

Perils of Commercial Beekeeping

Canada Free Press     By Paul Driessen    4/6/14
Honeybees pollinate crops but endure stress, parasites and disease.  Solutions are coming.

 

One of America’s earliest food crops – almonds – is also one of the most important for commercial beekeepers. Almonds depend on bees for pollination, but the explosive growth of this bumper crop taxes the very honeybees the industry needs to thrive. 


California’s Central Valley produces over 80% of the world’s almonds, valued at over $4 billion in 2012. The boom is poised to continue, with new food products and expanding overseas markets increasing demand to the point that no young almond trees are available for purchase until 2016.

Demand for almonds translates into demand for pollination. So every year commercial beekeepers transport some 60% of all US honeybees to California’s almond groves in February and March, when it’s still winter in most other states. It’s one of their biggest challenges.

For one thing, bee colonies...

Read more...  
http://canadafreepress.com/index.php/article/62226

Note: Paul Driessen is a senior fellow with the Committee For A Constructive Tomorrow and Center for the Defense of Free Enterprise, nonprofit public policy institutes that focus on energy, the environment, economic development and international affairs. Paul Driessen is author of Eco-Imperialism: Green power, Black death

Pesticides 'Making Bees Smaller'

The Guardian    1/20/14

Bumblebees exposed to a widely-used pesticide produced workers with lower body mass, scientists find

Bumblebees could be shrinking because of exposure to a widely-used pesticide, a study suggests. 

Experts fear smaller bees will be less effective at foraging for nectar and carrying out their vital task of distributing pollen. 

Scientists in the UK conducted laboratory tests which showed how a pyrethroid pesticide stunted the growth of worker bumblebee larvae, causing them to hatch out reduced in size. 

Gemma Baron, one of the researchers from the School of Biological Sciences at Royal Holloway, University of London, said: "We already know that larger bumblebees are more effective at foraging. 

"Our result, revealing that this pesticide causes bees to hatch out at a smaller size, is of concern as the size of workers produced in the field is likely to be a key component of colony success, with smaller bees being less efficient at collecting nectar and pollen from flowers." 

Pyrethroid pesticides are commonly used on flowering crops to prevent insect damage. 

The study, the first to examine the pesticides' impact across the entire lifecycle of bumblebees, tracked the growth of bee colonies over a four month period. 

Researchers exposed half the bees to a pyrethroid while monitoring the size of the colonies as well as weighing individual insects on micro-scales. 

They found that worker bees from colonies affected by the pesticides over a prolonged period grew less and were significantly smaller than unexposed bees. 

Findings from the study, funded by the Natural Environment Research Council (Nerc), appear in the Journal of Applied Ecology

Professor Mark Brown, who led the Royal Holloway group, said: "Bumblebees are essential to our food chain so it's critical we understand how wild bees might be impacted by the chemicals we are putting into the environment. 

"We know we have to protect plants from insect damage but we need to find a balance and ensure we are not harming our bees in the process." 

Currently a Europe-wide moratorium on the use of three neonicotinoid pesticides is in force because of their alleged harmful effect on bees. 

As a result, the use of other types of pesticide, including pyrethroids, is likely to increase, say the researchers. 

Dr Nigel Raine, another member of the Royal Holloway team who will be speaking at this week's national Bee Health Conference in London, said: "Our work provides a significant step forward in understanding the detrimental impact of pesticides other than neonicotinoids on wild bees. 

"Further studies using colonies placed in the field are essential to understand the full impacts, and conducting such studies needs to be a priority for scientists and governments." 

The scientists sprayed the pesticide on the bees' pollen feed at the concentration recommended for oilseed rape. 

Colony growth and reproductive output were monitored for up to 14 weeks. 

http://www.theguardian.com/environment/2014/jan/20/pesticides-making-bees-smaller