bee forage pesticides pollinator threats

Transgenic crops and honey bees

Transgenic crops were first introduced into the United States in 1996 and have become a major component of American agriculture. In a transgenic organism (also known as a genetically modified organism) some genes from one species are spliced into the chromosomes of another species. This is quite different from traditional plant or animal breeding in which individuals with desirable characteristics are crossed with other individuals having desirable characteristics.

By 2007 three transgenic crops—soybeans, cotton, and corn—were planted on 280 million acres worldwide, mostly in the United States. Many of these plants are registered as pesticides with the Environmental Protection Agency. (That’s right, your morning cornflakes may be made with a registered pesticide, but I digress.) In Canada, a large portion of the 17 million acres of oilseed rape (canola) is transgenic and the percentage is increasing every year.

There are two major types of genetic modification, both of which have implications for honey bees. One type of transgenic crop is resistant to certain herbicides, and one type is resistant to insects. Some crops, such as cotton, have been modified to resist both. Honey bees are regular pollinators of oilseed rape, frequently visit cotton and corn, and occasionally visit soybeans.

Insect-resistant crops

The insect-resistant genes have been transferred from Bacillus thuringensis (Bt), a bacterium that lives in the soil. The introduced genes produce an endotoxin throughout the plant that causes damage to the walls of the gut in susceptible insects. The damaged walls leak their contents into the lumen (interior space) of the gut, causing death of the insect. Researchers fear that Bt toxin in the pollen could damage the adult nurse bee gut or the larval honey bee gut.

Although many scientists have looked at the possible effects of Bt plant pollen on bees, so far there is no evidence of injury. However, because the toxins in the plants are able to kill the larval stages of other insects such as moths, butterflies, beetles, and weevils, many people believe that trouble may lie ahead as other plants—which may produce slightly different toxins or different quantities of toxin—become available. Currently only corn, cotton, potatoes, and tomatoes are commercially available with Bt genes. But in 2008 field trials were conducted on 30 additional crops, including apples, cranberries, grapes, peanuts, rice, soybeans, poplar, sunflowers, and walnuts.

Herbicide-resistant crops

The herbicide-resistant crops have a gene that resists glyphosate (RoundUp). This gene, too, was isolated from a bacterium. While the gene itself seems to have no adverse effect on insects, the application of glyphosate eliminates all the plant life except the resistant crops. Flowering weeds within the crops, as well as those in ditches, borders, paths, and irrigation canals are all killed, leaving the bees a very poor diet of only one flowering species.

A large number of researchers believe that these monoculture diets are a major factor in honey bee decline. Poor diet leads to loss of vigor and a depressed immune system which makes bees more susceptible to pathogens, parasites, and other stressors.



  • Yes, it’s directly related. I think about pesticides a lot and it makes me squirm because humans eat all that stuff too. Somehow, our government thinks it’s okay to have pesticides in our food.

    I hope it’s not too technical. I think pesticides, including transgenic crops, will end up being at least partially responsible for Colony Collapse Disorder. And they are a major reason why we are losing our wild bees. I want people to think about it because it’s important for the future of the earth.

    Maybe after I graduate (two more weeks) I will get off the pesticide thing for a while. There is so much other bee stuff to think about.

    Anyway, thanks for writing. It’s always good to hear from you!

  • I don’t think it’s too technical. You do a good job of organizing the information, which keeps it from being overwhelming. Pesticides make me shudder, too. And then I was reading something about how, if you think about jet fuel and chemtrails, well, nothing is really organic. We have built a very toxic place for ourselves to live.

    I would agree with you (with far less research into the matter) that we will ultimately find a link between the disappearance of our bees and pesticides/transgenic crops. We’ve got to keep growing those heirlooms and OP veggies and planting our good, native gardens.

  • I am a Chinese researcher for honeybee product. I want to know more information about transgenic honeybee product, so your website is pretty platform.

    Thanks a lot!

  • I hope you you’ve continued your studies. Thanks from me, a survivor of non-hodgkin lymphoma, who has multiple disciplines including plant science (horticulture) disease, environmental science and ergonomics (habitation). The one question I have had that no one in government can answer (for reasons known only to them). They flat out lie and then have the huspa to label themselves as “ethical” but if you call them on it the simply delete you, PERMANENTLY (no joke, ethics is part of their name).

    If the oncogene which is a known as the trigger for cancer and this trigger is stimulated by nicotine. WHY ARE WE USING NEO-NICOTINES AT ALL? IS THE OBJECTIVE TO SPREAD CANCER TO EVERY LIVING BEING ON THE PLANET? Is anybody doing any proof of data by expert witness. I can tell you that watching the entire planet be destroyed by this very specific targeting group of chemicals after I’ve come off of chemotherapy is very disturbing. The facts are that large chemical companies who are using the political tricks and scare tactics to defend and retain their power! And why not? After all they are self regulated. Honey bees are the “canary in the coal mine” but then so were the deformations of frogs discovered by high school students living in rural Minnesota. I’m expecting similar studies to show starfish wasting to show similar results. So what do we do to reverse this deviation caused by the neonicotinoids? Is the dollar return on investment really worth it?

    Obviously these chemicals NEED TO BE DESTROYED IMMEDIATELY! Then research labs worldwide are going to (if we have the time) address this problem that humanity has created. I’ll never see the results. You see I’ve heart disease with assorted goodies now from “complications”. I know from complications, my wife died 4 years ago from chemical complications while in a nursing environment (about as close and personal as one can get). Very soon I’ll need to make some hard decisions. Like where to park my 70-year-old homeless butt when and if I come out of hospital next time. Cancer is deviating physically, mentally and let’s not forget economically deviating – I hope it never happens to you. Best of luck every one.

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