Declining Bees and Toxic Insecticides: Sources for A Complex Story

By Carl Zimmer | March 30, 2012 8:48 am

Earlier this week, my editor at the New York Times asked if I’d write a story about a pair of new papers in Science detailing experiments on how insecticides affect bees. Bees have been in decline in many places, and scientists have been trying to figure out the cause–or causes–of their fall. These two new experiments represent a new wave of more realistic tests, taking place on farms instead of in labs. They’re also important because they were designed to look at what happens when bees are exposed to more realistic, sublethal doses.  My story appears in today’s issue.

I found this story to be especially challenging to sum up in a single nut graph. To begin with, these experiments came after many years of previous experiments and surveys, which often provide conflicting pictures of what’s going on with insecticides and bees. The experiments themselves were not–could not–be perfect replicas of reality, and so I needed to talk to other scientists about how narrow that margin was. As they should, the scientists probed deep, pointing out flaws and ambiguity–in many cases even as they praised the research. At the same time, these two papers did not appear in a vacuum. Other scientists have recently published studies (or have papers in review at other journals) that offer clues of their own to other factors that may be at work. And, biology being the godawful mess that it is, it seems that these factors work together, rather than in isolation.

There’s a lot at stake with all this complexity. The insecticides in question–a class called neonicotinoids–earn well over a billion dollars a year for their manufacturers. These insecticides are everywhere. Virtually all corn in the U.S. is treated with them, for example. Meanwhile, just this month (before the latest studies came out), environmental groups stepped up their calls to get these insecticides off the market.

You can see for yourself how I tried to sketch out all this complexity in my piece. And if you want more information, here’s a list of key papers and other documents:

The two new papers, on honeybees and bumblebees.

A new review of previous research: “Dietary traces of neonicotinoid pesticides as a cause of population declines in honey bees: an evaluation by Hill’s epidemiological criteria,” by James E. Cresswell, Nicolas Desneux, Dennis vanEngelsdorp. Pest Management Science

Another new review: “Neonicotinoids in bees: a review on concentrations, side-effects and risk assessment.” Tjeerd Blacquière, Guy Smagghe, Cornelis A. M. van Gestel and Veerle Mommaerts. Ecotoxicology.

A recent paper finding that these insecticides let parasitic fungi grow faster. 

A recent paper finding that insecticides and fungi don’t kill a lot of bees separately, but are deadly in combination

A recent paper very similar to the new honeybee paper (tracking the insects with radio tags) that did *not* find the same kind of ominous changes.

A report that came out earlier this week from the Xerxes Society (an insect conservation group that supports lots of scientific research) calling for the suspension of neonicotinoids

An emergency petition from beekeepers and environmental groups to the EPA earlier this month calling for suspension of neonicotinoid insecticides. pdf

Pesticide Risk Assessment for Pollinators: an executive summary of a 2011 meeting organized by Bayer CropScience and the EPA, the Society of Toxicology and Environmental Chemistry, which will become a book later this year. pdf

[Photo by wwarby – via Flickr/courtesy of Creative Commons]

CATEGORIZED UNDER: Environment, Writing Elsewhere

Comments (15)

  1. 1) 50% decline of honey bees in the past 25 years.
    2) CDC: 78% increase in autism rates since 2002

    What changes were implemented in these time frames?

    1. Colony Colapse: Dual polarization weather radar capabilities were implemented in 1985, corresponding to the 25 year time frame of honey bee decline. (WEATHER RADAR DEVELOPMENT HIGHLIGHT OF NATIONAL SEVERE STORMS LABORATORY’S FIRST 40 YEARS) The Neonicotinoid class of insecticides implicated by the recent bee decline research, by comparison, were only introduced in the 1990s. (Economist, March 31 2012)

    2. Beginning in 1999, a secret program was implemented to track sex offenders using airborne weather radar (including commercial passenger airliners) pointed at the ground to scan pedestrians’ radar profiles. This corresponds to increased autism rates since 2002.

    “There are two major systems when talking about the receiver/transmitter: the first is high-powered systems, and the second is low-powered systems; both of which operate in the X-band frequency range (8,000 to 12,500) MHz. High-powered systems operate at power levels between 10,000 and 60,000 watts.” (Weather radar-Wikipedia)

    “all nerve tissue, especially the optic nerve, is very susceptible to X-band radiation and care should be taken to observe all manufacturers and FAA recommended safety procedures when working around a weather radar system that is radiating radio-frequency (RF) energy.” (Airborne Weather Radar-Separating Fact from Fiction)

    [CZ: Wow. I just have four words to offer in response: Pirates cause global warming.]

  2. Jim

    One of the fascinating aspects of honeybees is – despite what a common cultural fixture they are – how counterintuitive is the reality of their lives – contrary to what is generally observed and believed about their biology. This little piece seeks to convey the massive turnover of individual bees in the spring and summer months, such that – despite a constant or expanding total hive population, survival of individual bees is irrelevant to hive function and hive survival. Indeed, the hive is the thing, the hive – the colony – is the superorganism.

    Late winter

    Somewhere among the teeming masses,
    clustered thick as bees in the hive’s dark halls,
    comes a signal to turn up the heat :
    from low 80’s,
    the central set point moves to 95 …
    the nursery now opens for the season.

    The queen begins her labor,
    touching down into
    each clean wax cradle
    a single oblong pearl,
    its thin shell enclosing the one-cell spawn
    – egg of mother bee –
    fertilized as it’s laid
    by seed from one of a dozen fathers
    – each dead as he gave his all last year.

    This simple act she does
    again and again and again,
    cell after cell after cell,
    day after day after day
    in the warm darkness of the brood comb
    … constant production for the season
    – hundreds laid each day –
    hundreds each day emerging,
    adults after 3 weeks’ growth,
    foraging force for the coming harvest.

    Yet among the colony’s tens of thousands,
    as winter turns to spring,
    and on throughout the summer,
    hundreds each day die without fanfare
    after a month of flight in sunlit air …
    by mid-year – though it can’t quite be seen –
    every one of these will be gone, save the queen,
    a river of younger sisters and a stream of brothers
    filling and overfilling the hive …

    life of the resplendent whole
    dependent upon, yet indifferent to
    the brief lives of its parts.

  3. Mary

    If only there were ways to generate more target-specific treatments, with, I don’t know–proteins or RNAs or something instead.

    Oh wait, no, we don’t like GMOs. I do note that this work is done where there are few GMOs around, which are often blamed.

    (Btw: I get the same paper from both honeybee and bumble bee links)

  4. Cade DeBois (@lifepostepic)


    I have autism. Asperger’s Syndrome, to be exact, which I was dx’d with in 1999. I was born in 1971. My father had the same autistic traits as I do, no more or less “severe.” He was born in 1933. My grandfather was just like my dad and me is terms of autistic traits. He was born in 1901. My grandfather’s mother’s family considered these traits simply a quirk within the family, so it’s a good possibility to assume others in previous generations of my family had these traits. Another thing about my family: since they were francophones living within their own french-speaking community here in the US, they largely relied on one another. Families tolerated and accommodated certain quirks in certain members. But since my father’s generation, that tight community has been lost, and now my generation doesn’t have that to fall back on. Not surprisingly, I have struggled as an adult with getting by in a world that isn’t so accommodating towards quirky people like me as the community that my father and grandfather relied so much upon. This is large part why I ended up seeking a dx.

    I was able to get dx’d because of a sudden increase of awareness in autism in the 1990’s that led to Asperger’s being accepted as a dx in my country. It wasn’t like I suddenly started acting autistic in 1999–my first symptoms appeared as sensory issues when I was just an infant in the early 70’s. I had a long wait to find out why I am the way I am. I am the first person in my family to be officially dx’d with autism, and I wasn’t dx’d until I was in my late twenties.

    I think my family story indicates at least two reasons for the increasing numbers of autism dxs–simple increase in awareness and a shift in how our society accommodates (or doesn’t) “odd” people who may need more assistance socially. I know, I know–kind of anticlimatic after all the drama and hyperbole about this “epidemic.” Personally I suspect there is a complex of reasons, but don’t listen to me-I’m just someone with autism, from a family with a history of autism, who had spent over 15 years working with special ed children to booT. I’m clearly an unreliable voice in all of this. However, the simple, historical fact that people like myself and my dad and granddad exist show that whatever novel theory people throw around abut what causes autism, if it doesn’t take into account of generations of undx’d autistics who existed prior to 2000/2002/2006/whatever convenient cut-off date you want to use, it’s probably not worth the comment space it’s posted in.

  5. maria

    gmo and neconics have similar effects on honeybees. The EU has banned both on the precautionary principle and the honeybee population is rebounding. Hmm….also….”There’s a lot at stake with all this complexity. The insecticides in question–a class called neonicotinoids–earn well over a billion dollars a year for their manufacturers. These insecticides are everywhere. Virtually all corn in the U.S. is treated with them, for example. Meanwhile, just this month (before the latest studies came out), environmental groups stepped up their calls to get these insecticides off the market.” as stated by the author of this article, this is why the USA is not abiding by this principle and instead chooses to coin phrases like “colony collapse disorder” rather than give the public the TRUTH about why honeybees do not do well when nature is manipulated to serve the purpose of the chemical/biotech industry. Honeybees and nature as well as our own species would be much better off without the use of these toxins and instead work on developing renewable and regenerative practices and technologies that are proven to work while protecting our resources and biodiversity.

  6. jd

    @Cade: Bravo.

    I know it’s off-topic (hey, I didn’t start it), but many Aspies don’t consider their “problem” a problem at all. What is the biggest difference between Aspies and NTs (“normal” people, neurotypical)? We understand we suck at communication and reading body language. NTs seem to be under the delusion they can with a great deal of confidence, despite the huge mountain of literature showing their error. I can’t tell you how many times I’ve had the following conversation:
    Them: Why are you mad at me?
    Me: I’m not. I’m quite happy in fact.
    Them: Yes you are. I can see it in your face.
    Me: No, I’m really not. I’m just concentrating on what you are saying so I can understand you. This is my concentration face.
    Them: Yes you are mad.
    Me: I’m not angry.
    Them: Yes you are.
    Me: No, I’m not.
    Them: Yes.
    Me: No
    Them: Yes.
    Me: DAMMIT! I’m not mad at you!…Ok, now I’m angry, satisfied?
    Them: See? I told you.
    Me: GAAAAH!

    Why are NTs so flipping illogical and apparently crazy?

  7. David B. Benson

    The precautionary principle indicates…

  8. @ Carl – It’s nice to hear that you can have trouble with this sort of thing too. When all we ever see is the polished final version, it’s hard to remember sometimes that it’s not supposed to be effortless.

    One critique on something I know you have very little control over – the small image associated with your story shows protestors holding up a banner with “GMO” written on it. Conflating the environmental concerns of pesticides with protests against GMO’s seems like reinforcing a misleading stereotype. Just thought I’d bring it to your attention.

  9. Geack

    @ 6 maria,
    “gmo and neconics have similar effects on honeybees”… based on what, exactly? The phrase GMO encompasses a huge range of modified and modifiable traits in a huge range of plants. Which ones do you believe mimic the effects of neonicotinoids? Why?

    It’s pretty useless to lump a bunch of unrelated things together and then claim “these are all bad”. It’s purely dishonest to lump them together and then claim they’re all bad in the same way.

    The “precautionary principle” you mention basically boils down to “this stuff sounds scary, and since it’s impossible to prove that it’s 100% safe we’ll ban it.” The US, for better or worse, is working on the principle that everything we know about GMOs so far suggests they’re safe, and their benefits are unquestioned, so we’ll move ahead with cautious use.


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The Loom

A blog about life, past and future. Written by DISCOVER contributing editor and columnist Carl Zimmer.

About Carl Zimmer

Carl Zimmer writes about science regularly for The New York Times and magazines such as DISCOVER, which also hosts his blog, The LoomHe is the author of 12 books, the most recent of which is Science Ink: Tattoos of the Science Obsessed.


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