GMO Crops and Bees

New technologies are, rightfully, viewed with skepticism. One of our blog readers asks, “Is there any effect of transgenic crops on bees?” The use of genetic engineering involves transgenic material, a portion of one plant or animal, being inserted into another organism. The resulting plant or animal is described as being a “genetically modified organism,” or GMO. In the case of crops, the purpose of the transfer of genetic material is to produce a new crop with desired traits. A number of crops are regularly produced using transgenic technologies include corn, rice, soybean, cotton, and rapeseed. Some GMO crops, especially soybean, cotton, and canola (rapeseed), are regularly foraged by honey bees. Careful study continues to determine any effect that the planting of GMO crops that are food sources for honey bees will have on the health of the bees and the safety of the honey that the bees produce.

Currently, there are two principal uses of GMO technology used to produce agricultural crops. The first employs Bt (Bacillus thuringiensis) genes to produce a toxin in crop plants as a means of controlling insect pests. The second GMO technology in common usage is designed to control crop weeds. The herbicide glyphosate, known as Roundup, is in widespread use to control broad-leaf weeds and grasses. Genetically modified corn, canola, alfalfa, sugar beets, and cotton are resistant to glyphosate. The herbicide can be sprayed over the genetically modified, glyphosate-resistant crop plants and weeds, killing only the weeds. Neither Bt toxin nor glyphosate-resistant GMO technologies appear to be harmful to honey bees and other pollinators, nor do they contaminate honey. The use of glyphosate-resistant technology does have a negative effect on bees and insect pollinators when it destroys the weedy field margins that previously provided food and habitat for these insects. Today’s photo shows a GMO soybean field. Glyphosate herbicide killed the weeds and grass in the crop area and along the field margin, leaving soybean plants growing without competition.

--Richard

Superweeds and Superpests

The use of genetically modified crops was intended to reduce the need for herbicides to control weeds and insecticides to control pest insects. However, The New York Times reports that instead herbicide use increased over 16 years, while insecticide use decreased somewhat. The widespread use of a single herbicide glyphosate, sold under Monsanto’s brand name Roundup, has resulted in the evolution of a number of glyphosate-resistant weeds. The Times piece, http://green.blogs.nytimes.com/2012/10/05/the-legacy-of-pesticides-superweeds-and-superpests/?src=rechp, describes different approaches to the use of these genetically modified organisms. “Roundup Ready” corn, soybeans, and cotton seeds were planted on 1.37 billion acres from 1996 to 2011. The GMO plants, tolerant of the herbicide glyphosate, were supposed to reduce or eliminate the need to till fields and reduce the need for harsher chemicals. The use of these GMOs was supposed to also save money and be less stressful on the environment. As glyphosate-resistant weeds increased, increases in the use of glyphosate slowed; and in 2010 the National Research Council warned that, “Eventually, repeated use will render glyphosate ineffective.”

Those deploying the genetically modified seed containing the Bt gene producing toxins from the soil bacterium Bacillus thuringiensis recognized the potential for evolving resistant insects, and they took precautions. They required that a percentage of non-Bt seed be planted with Bt crops to ensure that some insects susceptible to the Bt toxin survive to mate with survivors of the Bt crops. Otherwise, surviving pest insect populations could become increasingly resistant to the Bt toxin with each generation. The mechanism for ecological harm from chemical pesticides was described by Rachel Carson in Silent Spring 50 years ago: “First, many of these chemicals are indiscriminate, killing not only pest but also the predators and parasites that help to keep them at bay. Second, surviving pest populations become increasingly resistant to the applied toxins with each generation, as those most susceptible to the toxins die off. It’s natural selection in overdrive.” Today’s photo: applying herbicide to control grasses in GMO soybeans.

--Richard

GMO Safety Questioned

I recently spoke with knowledgeable individuals from Europe, Africa, and Asia about their concerns with genetically modified crops grown in the United States. I explained that GMOs, genetically modified organisms, have been in use for nearly two decades, and we have been assured they are safe. Genetic modification involves inserting genetic material from one species into another to produce new properties. Current GMO technology has two purposes: pesticide production and herbicide resistance.  The first technology, “Bt,” inserts genetic material from Bacillus thuringiensis bacterium into plants to produce bacterial toxins to kill insects. The second technology involves creating “Roundup-Ready” crops resistant to the herbicide glyphosate, the active ingredient in the broadleaf week killer Roundup.

An article published in Mother Earth News, “The Threats from Genetically Modified Foods,” http://www.motherearthnews.com/sustainable-farming/genetically-modified-foods-zm0z12amzmat.aspx, points to possible health risks. Though we have been told by the makers of GMO seed and glyphosate of their safety, the article strongly questions this. It explains that the manufacturers make it nearly impossible for independent scientists to study genetically modified seeds. Researchers point to possible risks to human health with Bt crops causing damage to the small intestines and glyphosate causing malformations in animals. Also, glyphosate causes damage to wetlands through run-off, and causes soil damage. Researchers state that glyphosate “can significantly increase the severity of various plant diseases, impair plant defense to pathogens and disease, and immobilize soil and plant nutrients, rendering them unavailable for plant use.” These researchers also warn that glyphosate “may have dire consequences for agriculture such as rendering soils infertile, crops nonproductive and plants less nutritious.” Glyphosate herbicide can lead to disease and toxins in plants including toxin levels in straw high enough to make cattle and pigs infertile. In another GMO technology, “rBST,” genetically modified cattle growth hormone is injected into dairy cattle to increase milk production, resulting in high levels of a milk protein that increases the risk of breast, colon, and prostate cancer. Surely, GMO crops deserve independent scientific investigation. Photo: GMO Corn.

--Richard

Are GMOs Safe?

The recently reported study of a significant Indiana honey bee kill that was traced to the insecticide clothianidin drew questions about the crops involved. The study followed the flow of a systemic insecticide, coated onto corn seed, from crops and the surrounding soil to the bees and their hives. The study by Krupke et al. is published in the Public Library of Science at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0029268. Several readers questioned the safety of the treated crop, genetically modified, or GMO, corn. A large percentage of grain and food crops grown in the United States involve plants known as genetically modified organisms, crops that have been modified to have desirable traits either by altering the plant’s genes or by introducing genetic material from other organisms. Most crop GMOs accomplish two purposes: The first is to provide resistance in the crop plants to herbicides used to control competing weeds and grasses, and the second is to allow the crop plants to control insect pests. Genetically modified crops are tested for safety to beneficial insects, like honey bees, and for livestock and humans that consume the crops. While testing and observation continue, genetically modified crops appear to be safe. GMO grains have a history of safe use over a number of years. Researchers find no connection between GMO crops and honey bee Colony Collapse Disorder.

GMO crops also offer a number of advantages for modern agriculture. Crops resistant to specific herbicides, like glyphosate, can be grown weed-free by spraying the entire field. Weeds are killed, but the crop is not damaged. Glyphosate-resistant crops are often known as “Roundup Ready.” The use of genetically modified crops can reduce the need for mechanical cultivation, saving labor, fuel, and soil moisture by employing no-till practices. Also, GMO crop plantings often reduce the need for insecticides such as clothianidin. In today’s photo greater white-fronted geese, “specklebellies,” wintering in the Arkansas Delta, forage in a harvested soybean field. The Delta is seeing increased numbers of migratory waterfowl.

--Richard

GMOs and Neonicotinoids

Corn, or maize, is the most widely grown crop in the Americas. A beekeeper asked me if Bt corn and Roundup-Ready corn are dangerous to honey bees. This is among the commonly asked questions as beekeepers are facing annual colony losses of 30 percent. Beekeepers question the safety of chemicals used in the environment and changes in agricultural practices. Bt corn and Roundup-Ready corn are both Genetically Modified Organisms. In Bt corn, a gene is borrowed from the Bacillus thuringiensus bacteria. This modification allows the corn plant to produce its own Bt insecticidal protein. This technology allows for corn production with lesser application of insecticides, as the plant is producing its own insect killer. The effect of Bt corn on honey bees was tested in Germany from 2001 through 2004. Michael Schacker reports in A Spring Without Bees: How Colony Collapse Disorder Has Endangered Our Food Supply, 2008, that Bt crops and GMOs are not correlated with Colony Collapse Disorder. There may possibly be some benefits for bees and other pollinators from the use of Bt technology in corn, as this may lead to a reduction in the use of crop insecticides. Roundup-Ready corn can withstand the herbicide glyphosate. Herbicides, like Roundup, are being tested now; however, results have not been published.

Following the appearance of Colony Collapse Disorder in 2007, the effect on honey bee health is questioned for all chemicals used around bee hives. A relatively new class of insecticides, the neonicotinoids, is highly suspected by many beekeepers as being involved in CCD and honey bee health problems. Among these systemic insecticides are imidacloprid and clothianidin. Of particular concern is the effect upon the bees of a less than lethal dose of a neonicotinoid insecticide when combined with certain honey bee viruses or the newly detected strain of Nosema disease. Honey bee colony collapses often occur in the winter. This winter has seen greater than normal snowfalls in the Arkansas Delta. Today’s photo: common starlings weather the snow.

--Richard