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

Vanishing Monarchs

Animals that consume a narrow diet are much more vulnerable than those eat a varied diet. While the honey bee derives its nutrition from many flower sources, the larvae of another insect, the monarch butterfly, relies solely upon one, the milkweed plant. Recent years have seen dramatic declines in the number of monarch butterflies. Robert F. Kennedy Jr. writes in the Chicago Tribune, http://www.chicagotribune.com/news/opinion/commentary/ct-monarch-butterfly-herbicide-kennedy-perspec-102-20141021-story.html, that this past summer he saw no monarch butterflies in an area where he saw hundreds per day in previous years. Kennedy explains that scientists blame the loss of monarch butterflies in part on deforestation in Mexico, drought, climate change. However, the greatest cause of this migrating butterfly’s disappearance is the widespread use of the herbicide glyphosate, first marketed by Monsanto as Roundup. When Monsanto introduced “Roundup Ready” corn and soybeans in the late 1990s, farmers started spraying agricultural fields with the herbicide to kill everything except the desired crop. As a result of this change in farming practice, milkweed has been largely eliminated from much of America’s crop lands. To combat the loss of the monarch’s food, Kennedy suggests that we plant milkweed to create a “butterfly highway” along the monarch’s migratory route from the U.S. and Canada to Mexico. These plantings fit in nicely with efforts to help save bees, butterflies, and other at-risk pollinators.

The monarch’s treacherous migration of 2500 miles involves several generations. Butterflies east of the Rockies fly to Mexico to spend the winter, and monarchs west of the Rockies winter in California. The Arkansas Democrat Gazette illustrates their migration route through Arkansas at http://www.arkansasonline.com/news/2014/oct/25/milkweed-and-monarchs-20141025/. Those wanting to provide milkweed for the passing butterflies can find sources of seed from the Xerces Society at http://www.xerces.org/milkweed-seed-finder/.  The monarch, considered by some as the most beautiful insect may respond to plantings of its required food in pollinator gardens. With flowers added, these gardens are important food plots for honey bees and native pollinators as well.

--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

Resistant Pests and Weeds

Agricultural weeds and honey bee pests regularly develop resistance to chemical treatments, especially when the chemicals are used repeatedly. Six authors present diverse views on the increasing problem facing American industrial agriculture as the list of weeds resistant to the most commonly used herbicide increases. Log onto today’s New York Times opinion piece at http://roomfordebate.blogs.nytimes.com/2010/05/06/invasion-of-the-superweeds/ to read these authors’ thoughts on the causes of ten species of weeds evolving a resistance to Glyphosate. They also offer a range of possible solutions to correcting the problem by changing agricultural practices. Glyphosate, known by the name Roundup and other names, is used extensively with genetically modified crops that have been designed to be tolerant of the effect of the herbicide. While weeds evolve a resistance to Roundup in the fields, honey bee pests evolve a resistance to chemicals in the small environment of the bee hive. Beekeepers have seen American foulbrood, a bacterial disease, become resistant to antibiotics. Parasitic Varroa mites rapidly evolved to become resistant to each of the chemical miticides used in the bee hive. Corn, soybean, and cotton farmers are finding it necessary to use different herbicides and mechanical cultivation techniques to control Roundup-resistant weeds. Many beekeepers are moving away from the use of antibiotics and miticides in an effort to keep bees healthy without building strains of resistant pathogens and pests.

Today’s picture shows Palmer pigweed, one of the six species of Roundup-resistant weeds found in Arkansas. The plant, taller than a person’s head, stands outside a hundred-year-old barn at Peace Bee Farm. I regularly see Palmer pigweed standing above crops in nearby fields. Roundup is a most useful herbicide used by beekeepers to control foliage around bee hive stands. As a test, I sprayed the pigweed by the old barn with Roundup. The tall weed was easily killed by a single spraying at the labeled concentration; it was not resistant. Row-crop farmers and bee farmers should continuously evaluate their Integrated Pest Management approaches.

--Richard

Elderberry and Pigweed

The elderberry is a tall, common shrub of roadsides and forest margins. Throughout July, the plants were crowned with broad clusters of small, white, fragrant flowers. Now the flowers, pollinated by honey bees and other insect pollinators, are giving way to prolific bunches of berries. In the photo, the elder berry shows white flowers as well as green and dark purple berries. The ripe berries will darken and turn black in color. Elderberry is one of the flowering plants that go a long way toward supporting wildlife. The plant is browsed by deer. The berries are eaten by rabbits, fox, and squirrels. At least 25 species of birds including indigo bunting, bluebird, catbird, mockingbird, brown thrasher, phoebe, robin, dove, quail, turkey, and woodpeckers regularly eat the fruit of the elder berry plant. The elderberries are used to make pies, preserves, and wine.

The Memphis Commercial Appeal reported yesterday that hundreds of thousands of acres of soybean and cotton fields in the Mid-South have been infested by an herbicide-resistant strain of a common weed, Palmer pigweed. The pigweed is thriving in the presence of the most commonly used chemical herbicide, glyphosate, which is commonly sold under the trade name Roundup. Soybeans, cotton, and other plants have been genetically engineered to withstand glyphosate, allowing the weed killer to be sprayed directly on the crops. The herbicide-resistant pigweed can’t be controlled by glyphosate, so farmers are being required to return to labor-intensive hand chopping of the weed. We find in agriculture that chemical resistance commonly occurs. That has been the case with beekeeping, as strains of miticide-resistant mites replaced the first mites to enter this country. The beekeepers are having to adjust their mite control tactics; now the row-crop farmers will have to do the same.
--Richard