From the Front Lines: Waging War on Bugs.

Healthy Roots on corn with no sign of corn rootworm

Healthy Roots on Corn with no sign of Corn Rootworm

In 1901 the bacterium Bacillus theringiensis (Bt) was found to be lethal to silkworms and soon after it was introduced as a pesticide for moths (order Lepidoptera). It was not until 1956 that the method of toxicity of this protein was understood by researchers and by 1961 the pesticide was commercially used in the United States. Research continued into the protein to include the discovery of strains that are toxic to flies (Order Diptera) and beetles (Order Coleoptera).1 Research has dramatically accelerated into molecular biology to encode the genes that produce the toxic proteins into plants. One of the most notable examples is corn where the following genetically modified corn variants (Bt Corn) are currently approved for use by the EPA: Cry1Ab, POCry1F, POCry1Ab, POCry34Ab1, MOCry1F, Cry34Ab1, Cry35AB1, Cry3Bb1, Cry3A, Cry1A.105, CryAb2, and Cry2Ab2. 2

Bt Corn made headlines in September of 2000 when the StarLink® brand (Cry9C) was approved by the EPA for use in domestic animal feed only. While StarLink® corn or any other variant has not shown to pose a risk to human health or the environment it was voluntarily pulled from the market when taco shells were found to contain Cry9C corn. 3,4,5

Until recently all of these strains have been highly effective at controlling crop damage from a large variety of insects, such as the major pest the Corn Rootworm (CWR). In areas where rootworms overpopulate, large sections of corn fall down as if knocked over by wind. In August 2011 Bt corn in Iowa began falling over, their roots nearly completely gone from rootworms. 6 The EPA issued a statement early in 2013 confirming resistance to Cry3Bb1 and will issue its findings later this year. 7 Farmers that have detected rootworm in their Bt Corn have resorted to using targeted organophosphate pesticides (OPs) like Force 3G® (Tefluthrin), Counter® 20CR (Terbufos), Lorsban®4E (chlorpyrifos), Fortress® 5G (chlorethoxyfos)and Aztec®(Tebupirimphos & Cyfluthrin) to name a few. Farmers not using Bt corn are left with more expensive alternatives that offer total protection against nematodes, insects and fungus for example Avicta Complete Corn 500 which contains a neonicotinoid pesticide thiamethoxam. 8  Some researchers believe the Neonicotinoids are a contributing factor in colony collapse disorder in bee colonies. 9,10

                        Bt crops has reduced the use of organophosphate pesticides but overall herbicide use has increased during that same time period.11 Analysis of common herbicides can be performed in 13 minutes using the Rtx-CLPesticides / Rtx-CLPesticides2 column pair fully optimized by Jason Thomas.12 The OP pesticides can also be analyzed using this same column pair. There are applications using these columns provided here:

US corn production for 2013/2014 is expected to exceed 13 billion bushels as the battle to protect crops continues.

Agrisure 3000GT combines two different Bt insecticidal proteins Cry1AB + mCry3A

Agrisure 3000GT combines two different Bt insecticidal proteins Cry1AB + mCry3A



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