# Newly Published Article Raises Questions About Pesticide Loads In Pollen



## BigDawg (Apr 21, 2013)

In what may be one of the most "real world" studies yet on the impacts of sub-lethal doses of pesticides upon honeybee colonies, researchers collected pollen samples from the field and analyzed them for pesticide loads. 

_"Pesticide exposure and pathogens may interact to have strong negative effects on managed honey bee colonies. *Such findings are of great concern given the large numbers and high levels of pesticides found in honey bee colonies. Thus it is crucial to determine how field-relevant combinations and loads of pesticides affect bee health.* We collected pollen from bee hives in seven major crops to determine 1) what types of pesticides bees are exposed to when rented for pollination of various crops and 2) how field-relevant pesticide blends affect bees’ susceptibility to the gut parasite Nosema ceranae."_

_"*We detected 35 different pesticides in the sampled pollen, and found high fungicide loads.* The insecticides esfenvalerate and phosmet were at a concentration higher than their median lethal dose in at least one pollen sample. While fungicides are typically seen as fairly safe for honey bees, we found an increased probability of Nosema infection in bees that consumed pollen with a higher fungicide load."
_

_"While multiple studies have shown negative effects of specific pesticides on honey bee individual and colony health [14], [15], [22], [26] and high pesticide exposure [27], [28], ours is the first to demonstrate how real world pollen-pesticide blends affect honey bee health."_

*"Insecticides and fungicides can alter insect and spider enzyme activity, development, oviposition behavior, offspring sex ratios, mobility, navigation and orientation, feeding behavior, learning and immune function [9], [13], [14], [16]–[22]. Reduced immune functioning is of particular interest because of recent disease-related declines of bees including honey bees [3], [23]. Pesticide and toxin exposure increases susceptibility to and mortality from diseases including the gut parasite Nosema spp. [14], [15]. These increases may be linked to insecticide-induced alterations to immune system pathways, which have been found for several insects, including honey bees [22], [24]–[26]."*


http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070182


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## BlueDiamond (Apr 8, 2011)

BigDawg said:


> In what may be one of the most "real world" studies yet on the impacts of sub-lethal doses of pesticides upon honeybee colonies, researchers collected pollen samples from the field and analyzed them for pesticide loads.


The study did not find the neonics are causing serious and widespread bee health problems.


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## BigDawg (Apr 21, 2013)

BlueDiamond said:


> The study did not find the neonics are causing serious and widespread bee health problems.


Correct, neonics did not play a huge part in this study--though it's worth noting that they were exclusively studying pollen and not nectar, AND, the only crop out of the seven they were studying that are routinely treated with neonics were Apples, and they did find neonics in the pollen from apples.

What's more troubling is the fact that fungicides appear to be having a much larger impact than previously thought. In fact, fungicides were previously considered pretty benign for bees. 

*“There’s growing evidence that fungicides may be affecting the bees on their own and I think what it highlights is a need to reassess how we label these agricultural chemicals,” Dennis vanEngelsdorp, the study’s lead author, told Quartz."*

Even more problematic is the discovery that there is a veritable witches brew of pesticides and fungicides inside the hives. Very little is known about how these pesticides interact with each other once they are brought into the hive:

*"The pollen was contaminated on average with nine different pesticides and fungicides though scientists discovered 21 agricultural chemicals in one sample. Scientists identified eight ag chemicals associated with increased risk of infection by the parasite."*

In addition, the research showed that a lot of the pesticide load was coming from weeds and wildflowers near the planted crops--even though those plants are not the targets of spraying--and yet they still carry heavy pesticide loads.

*"The study found another complication in efforts to save the bees: US honey bees, which are descendants of European bees, do not bring home pollen from native North American crops but collect bee chow from nearby weeds and wildflowers. That pollen, however, was also contaminated with pesticides even though those plants were not the target of spraying."*

I agree with the author's conclusions--that this problem is much more complicated than previously thought. 

“The pesticide issue in itself is much more complex than we have led to be believe,” he says. “It’s a lot more complicated than just one product, which means of course the solution does not lie in just banning one class of product.”

Clearly, much more research is needed. Clearly, many people have vastly underestimated the cumulative negative impacts upon non-target pollinator species from the multitude of agricultural pesticides and fungicides currently applied to the world's food supply.

http://qz.com/107970/scientists-discover-whats-killing-the-bees-and-its-worse-than-you-thought/


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## Barry (Dec 28, 1999)

BigDawg said:


> Clearly, many people have vastly underestimated the cumulative negative impacts upon non-target pollinator species from the multitude of agricultural pesticides and fungicides currently applied to the world's food supply.


I don't think so. It appears that _most_ people here hold this view and fewer hold the extreme views that it's all neonics or neonics have no impact at all.


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## jim lyon (Feb 19, 2006)

Good observation Barry and its the crux of what I have been arguing for quite some time. I guess blaming neonics is just in vogue right now. There are just so many stressers out there (some of them beekeeper applied) that to simply pick one group primarily because it "plays well" in the media is just an oversimplification of a really complex problem. I would agree that there is at least as much evidence out there implicating fungicides with bee losses yet no one seems to want to research them.


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## BernhardHeuvel (Mar 13, 2013)

jim lyon said:


> .. fungicides with bee losses yet no one seems to want to research them.


Some do. http://www.tandfonline.com/doi/abs/10.1080/15287394.2013.798846#.UfA7LWthiSM


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## BlueDiamond (Apr 8, 2011)

jim lyon said:


> There are just so many stressers out there (some of them beekeeper applied) that to simply pick one group primarily because it "plays well" in the media is just an oversimplification of a really complex problem. I would agree that there is at least as much evidence out there implicating fungicides with bee losses yet no one seems to want to research them.


But the beekeeper applied stressors and fungicides were present 10-20 years ago when annual colony losses were only 15%; e.g. I know from first hand experience working at an ag chemical dealership that way back in the early 1990's beekeepers were purchasing Mavrik to make their own fluvalinate based varroacide. So I don't see how additional research on the impact of fungicides or even beekeeper applied chemicals is going to help improve the current 30% annual colony loss statistics. I sometimes wonder how accurate those statistics really are; i.e. might the 15% figure actually be an underestimate of pre-2006 annual colony losses or the 30% figure an overestimate of post 2005 annual losses?


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## jim lyon (Feb 19, 2006)

BernhardHeuvel said:


> Some do. http://www.tandfonline.com/doi/abs/10.1080/15287394.2013.798846#.UfA7LWthiSM


Let me rephrase. "Few want to implicate them as a potential factor in some bee losses"


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## Keith Jarrett (Dec 10, 2006)

BlueDiamond said:


> But the beekeeper applied stressors and fungicides were present 10-20 years ago when annual colony losses were only 15%;


True, But likes the fungicide Pristine is a death sentence on queen cell production. Most of the cell buildiers in Cali are kept far away from any almond blooming orchard during the month of March.


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