18-Year Study Links Neonicotinoids to Bee Colony Decline

By Nathaniel Scharping | August 16, 2016 2:59 pm

(Credit: Dancestrokes/Shutterstock)

A type of insecticide used on oilseed rape plants in the U.K. is likely to blame for worrying declines in bee populations across the pond.

Over the past few decades, bee populations around the world over have declined precipitously. Habitat loss, viruses and pesticides are fingered as culprits, but a recent 18-year study in England focuses the blame largely on neonicotinoids, a type of insecticide approved there in 2002 for agricultural use. The researchers monitored 62 species of bees between 1994 and 2011, including 34 species of bees that forage on oilseed rape plants and 28 that do not.

Sharp Contrast

Species that rely on the oilseed plants are three times more likely to experience population declines than those that do not, researchers concluded. In five of the worst-affected species, the declines topped 20 percent, rising to 30 percent for the worst-hit species, the sharp-collared furrow bee. They published the results of their study Tuesday in Nature Communications.

Neonics have previously been shown to cause adverse effects in bees in small-scale laboratory studies, but this is the first time it has been linked to bee population decline in nature.

“Prior to this, people had an idea that something might be happening, but no-one had an idea of the scale,” said Ben Woodcock, lead author of the paper and a researcher at the Natural Environmental Research Council Center for Ecology and Hydrology in the U.K., speaking to Reuters. “(Our results show that) it’s long-term, it’s large scale, and it’s many more species than we knew about before.”

Bees Under Pressure

While neonicotinoids do not necessarily directly kill the bees, they cause a range of sub-lethal problems, say the researchers. Depending on the kind of bee, the chemical can cause bees to eat or forage less, negatively affect reproduction cycles, and disrupt flying and navigation, all of which reduce their overall fitness and place additional stress on the hive.

Neonics are no stranger to controversy, as studies have arrived at competing conclusions about how they affect hive health. According to a USDA-led study, neonicotinoids, in quantities used for agricultural purposes, “had negligible effects on colony health and are unlikely a sole cause of colony declines.”

Chensheng Lu, a Harvard environmental scientist, was also hit with a wave of criticism after he published a study in 2014 “definitively” linking colony collapse disorder with neonics. It turned out that bees in the study received doses of the pesticide at levels 10 to 100 times the level they would encounter in the wild. No surprise, his methods were called into question and dismissed as unreliable.

Bans Nonetheless

Neonicotinods were placed under moratorium by the European Union in 2013 after evidence of harm to bee colonies emerged. That temporary ban is set to be reviewed this year. The pending Brexit could affect the status of that ban, however, as the moratorium came from the EU — some exemptions to the ban are already in place in Britain.

Some U.S. states, such as Maryland, have already banned the chemical. Last year, sulfoxaflor, a neonicotinoid insecticide, was banned across the U.S. Several other forms of the pesticide are up for review by the EPA in the next two years.

CATEGORIZED UNDER: Environment, Living World, top posts
  • Doc2222

    But…but…but…how will poor corporate farmers be able to squeeze every last nickel out of every last living thing on earth if they can’t spew poison all over the landscape? Crazy communist liberals don’t want anybody to prosper like God said we should!

    • OWilson

      I assume you grow and catch your own food, and would never venture into a supermarket.

      That about right?

      • Doc2222

        Do you have a point?

        • OWilson

          Yeah, but it’s way over your pay scale. I’ll re-phrase it for you.

          “Like, I mean ah, Dude!, those dumb hicks, rubes, hayseeds, do more than poisoning your landscape.”

          Fixed it for ya!

          • Doc2222

            LOL…I didn’t think you had one. No surprise there…ho hum…..

          • OWilson

            “LOL” and “ho hum” in one short comment?

            You should see somebdy about those mood swings! :)

      • Maia

        It’s not necessary to use neonics to grow food…so…”just say no”…? There are farms/farmers who do not use it or most other supertoxins, we can support them AND the bees.
        Bees and other pollinators are well worth protecting if no other reason than for their “environmental services”.

        • OWilson

          Nobody out there wants to kill bees, least of all farmers.

          People, yes! :)

        • AshleyNicely ✓ᵀᴿᵁᴹᴾ

          Do you have first-hand experience with this? Very minute quantities of neonicotinoids have better effectiveness that huge quantities of pesticides that are far more harmful to life forms other than insects. your statement,”Bees and other pollinators are well worth protecting if no other reason than for their “environmental services” is correct only in an argument that has no opposing viewpoint; we are choosing not just to protect bees or not, we are choosing bees over other agricultural products; this does not necessarily put European honey bees in the mix. Many native bee species do not operate like honey bees, and as a result may not experience the effects of a very long term hive existence like honey bees do. The subject is being overrun by shrill eco-hysteria instead of intelligence science.

          • Maia

            “we are choosing bees over other agricultural products; this does not
            necessarily put European honey bees in the mix as being sacrosanct” Products? Inappropriate verbiage. I agree about European honeybees not being at the top of a list, but they are on the list. Native bees show evidence of harm just as Europeans do, and their numbers are falling as well. I read a couples of books about the situation in England: bumblebees are endangered. There are groups trying to save them by planting flowering species back where they were before so many were killed off. I agree, too, that doing deeper research is a help for conversations on controversial topics. When I said other pollinators, I had in mind nectar flies, beetles, butterflies, moths, some hummingbirds, and more… NONE are unharmed by ingesting toxins, whether or not there are also new viral, bacterial, fungal, etc threats. All of the above are happening. It helps to take out the toxins whenever possible. Pollinators are not farm animals because they are mostly “wild”, not owned by a human.

            European bees are “slaves” allowed to eat sugarwater in their quarters, expected to gather pollen, nectar, and do their work, but they are not free. And they don’t get time off, either. This is part of what is killing them off. Plus toxins.

            We have to be willing to look at the whole picture, and it points to humans as the main problem. As usual.

          • Gerald Wonnacott

            Uh, native bees are in serious decline for reasons similar to European bees.

          • Maia

            Yes, that’s right, native bees, and most all pollinators are in trouble due to habitat loss and pesticides. But, so far, they are not captive, trucked around the country and fed sugar, doused with chemicals in their hives, and alll the other “industrial” practices.

  • Stewart Herring

    If you want farmers to stop using neonics, then appeal to their parsimony.
    I believe that studies have shown that there is NO increase in crop yields where neonics are used. The farmers should be asking “Why pay for a treatment that has no effect on my yields?”

    • AshleyNicely ✓ᵀᴿᵁᴹᴾ

      As a part-time farmer, I can assure you that small applications of these pesticides have tremendous effects in increasing crop production. What these arguments against consistently leave out is the use of these pesticides on crops which are not pollinated by bees and which would have no effect on bee populations. They are applicable by soil drench so there is no problem with drift. The issue is never expolored in full to relate and discuss honey as a crop, honeybees as a pollinator, wind pollinated crops (corn, nuts, etc.) self-polinating crops, and the like. Eliminating neonicotinoids to protect a product, European honey bees, with a certain commercial value, at the detriment of other crops whose simple increase in value more than outweighs the value of the honey bee as a form of produce or pollinator simply makes no sense. The honey bee in not native to 90% of its range, and is not necessary for most crop production. A more balanced and scientific approach to the entirety of the contributions/harm of these products needs to be taken before shrill voices lead to unnecessary and detrimental regulation. Certainly, banning the non-agricultural use of these neonicotinoids should be considered; but the fact remains that this is an amazingly eco-friendly product which can be a great boon to the crop production necessary to human life.

  • Eric Thorson

    Proper citation needed. Here fixed it for you!

    How to cite this article: Wu-Smart, J. and Spivak, M. Sub-lethal effects of dietary neonicotinoid insecticide exposure on honey bee queen fecundity and colony development. Sci. Rep. 6, 32108; doi: 10.1038/srep32108 (2016).


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