Earlier this year, research conducted by the University of Minnesota and Iowa State University linked the declining monarch butterfly population to the rise in genetically modified crops.
Monarch butterflies lay their eggs on milkweed, which used to often be present on the edges of cornfields. The caterpillars then feed exclusively off of the milkweed.
However, since the introduction of crops that can withstand heavy herbicide use, more herbicide has been used on farms and milkweed has disappeared. Without this food source, caterpillars struggle to survive.
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