Neonicotinoids and their Effect on Honey Bees

Neonics and Bees

Last week Morgan Spurlock’s Inside Man was all about bees. He did a nice job of skimming a few really important issues in beekeeping and bee population. He visited with small and commercial keepers, gave an overview of Colony Collapse Disorder, showcased commercial pollination, investigated honey imports, and addressed pesticide use and its effect on honeybees. Last weekend I attended the Michigan Beekeepers Conference at Michigan State University and specifically a class about the effects of pesticides on honey bees.  The man, a professor at MSU, who presented did not seem completely convinced that resolving the pesticide issue alone would resolve the bee crisis. While I do agree that it will not solve the bee problem, I certainly feel that it would help it considerably.  Additionally, as a human who eats food, I’d prefer to eat fewer chemicals, so there is that food safety component as well. The pesticides we’re talking about here are neonicotinoids.  These are insecticides and, since bees are insects, they can and will kill bees. The question is, are they? Certainly if bees are on a plant being sprayed, they will be killed, but what about plants, like corn, soy, or sorghum, whose seeds are coated with it?


These seeds might be pretty to look at, but according to Walter Pate (the MSU entomology professor who taught the class I was in) just one insecticide-coated corn kernel contains enough poison to kill 80,000 bees. That’s in a concentrated form, of course. And most large-scale farmers use machinery to plant seed, almost blasting it into the dirt. The concern in this case, is the dust. Dust produced while these chemically-coated seeds are being planted settles on nearby plants, flowers, and in puddles – all places bees land and feed. So bees are then carrying insecticide residue back to the hive with them. Can this kill a hive outright? Yes. Can exposure leave lasting issues? Affect the brood? The general workings of the hive? The queen’s ability to lay? We aren’t sure.  That’s a lot harder to study. The other issue affects both bees and humans. If we are planting insecticide-coated seeds, and that insecticide is present enough in the plant and fruit that it kills insects, then it is also clear that we are consuming insecticides on a daily basis. The amount of neonicotinoid residue found in a tomato, for example, is safe for human consumption, according to the EPA. However, there have not been adequate studies recording long term exposure. For example, it might be perfectly safe to eat a tomato, but what about the cucumber also on your salad? What about the ear of corn you have with dinner? Or the many, many food products that contain soybean oils? And do these residues accumulate in your body? These are details that have not been researched in any great extent. There is some evidence to suggest that the excretions of plants does contain chemicals and in such a quantity that it is deadly to pollinators. This paper, published in 2009 by several Italian entomologists, explains how insecticides like neonicotinoids can be transferred from a corn plant to a honey bee.

Guttation is a natural plant phenomenon causing the excretion of xylem fluid at leaf margins. Here, we show that leaf guttation drops of all the corn plants germinated from neonicotinoid-coated seeds contained amounts of insecticide constantly higher than 10 mg/l… The concentration of neonicotinoids in guttation drops can be near those of active ingredients commonly applied in field sprays for pest control, or even higher. When bees consume guttation drops, collected from plants grown from neonicotinoid-coated seeds, they encounter death within few minutes.


So what can we do? There is a website called Driftwatch that is just gaining momentum and is being utilized by some states more than others.  This site allows farmers and beekeepers alike to enter their information. This way, farmers and keepers can coordinate and help protect the bees when seeds are being planted and/or fields being sprayed. As a beekeeper, if I know a farmer within a 2-5 mile radius is planting corn Tuesday and Wednesday, then Monday night (after all the bees are home for the evening), I’ll close the hive up. This could help keep bees safe from direct spray and initial run-off and early residues, but the other way to get the insecticides out of the plants, is to stop using them. Also, the EPA recently released a new labeling for neonicotinoids that details how harmful they are to honey bees along with directions for usage. There has not been any information about enforcement, however.  

**To learn more and to donate to our cause, visit our fundraising page HERE


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