New Study: Neonicotinoids Found to Drive Butterfly Declines More Than Any Other Environmental Variable

A new study published in PLOS ONE indicates that agricultural insecticides are significantly contributing to the decline of Monarchs and other butterfly species across the American Midwest. Using 17 years of land use, weather, multiple classes of pesticides, and butterfly survey data across 81 counties in 5 Midwestern states, researchers found that shifts in pesticide use are associated with an 8 percent decline in butterfly species diversity and individual population declines. These findings include the decline of the migratory Monarch Butterfly, with insecticides contributing to a comparative decline of 33 percent. Among the biggest culprits are seeds coated with neonicotinoids, or “neonics,” providing further scientific evidence that stricter regulations must be put in place to halt population declines of insect pollinators and the birds they sustain.

“With this alarming study, the mountain of evidence for the environmental harms of neonics continues to grow,” said Hardy Kern, Director of Government Relations, Pesticides and Birds Campaign at American Bird Conservancy (ABC). “We now know for a fact that neonics are directly causing populations of insects to decline, reducing a critical food source for birds, as well as harming birds directly. To ensure a safer, less toxic future for birds, the Environmental Protection Agency needs to address how seed treatments are regulated. These chemicals pollute soils and waterways, affecting creatures far from the aphids or grubs they’re intended to kill. Neonics are widely banned in Europe due to their demonstrated environmental harm, but in the U.S. we continue to permit their use. The EPA must act now to stop the devastating effects of neonics on wildlife.”