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