WASHINGTON— A study published today in the journal Nature finds that the use of neonicotinoids, the most widely used insecticides in the United States, has serious consequences for wild bees. The study, conducted in Sweden, finds that in field conditions, neonicotinoid use as a seed coating reduces wild bee density, solitary bee nesting and bumblebee colony growth; it concluded that the “contribution of pesticides to the global decline of wild bees may have been underestimated.” The findings have implications for America’s pollinators because neonicotinoid seed coatings are used on about 99 percent of corn seeds in the United States.
“There’s no question that these super-toxic pesticides are taking a heavy toll on imperiled native pollinators around the world,” said Jonathan Evans, Environmental Health legal director at the Center for Biological Diversity. “Native pollinators are a critical link in our food web. We need the EPA to step up and take action to ban these dangerous chemicals before it’s too late to save our wild bees.”
While the vast majority of studies have focused on the effects of neonicotinoids — also known as “neonics” — on honeybees, today’s study joins a growing body of science finding the chemicals are harming ecologically vital native pollinators.
“A quarter of all U.S. bumblebees are currently threatened with extinction,” said Evans. “Wild bees are essential for functioning ecosystems, but unless our regulatory agencies take action to protect them, many more bees and pollinators will head toward extinction.”
The Nature study also found important differences in the effects of neonics on honeybees and wild bees because “honeybees are better at detoxifying after neonicotinoid exposure compared to bumblebees.” While honeybees have suffered from chronic exposure to these pesticides, the study finds that wild bees are more sensitive to the acute toxic effects of neonics.
Neonicotinoids are a class of pesticides known to have both acute and chronic effects on honey bees, birds, butterflies and other pollinator species, and are a major factor in overall pollinator declines. These systemic insecticides cause entire plants, including pollen and fruit, to become toxic to pollinators; they’re also slow to break down, and they build up in the environment. A large and growing body of independent science, including today’s study, links neonics to catastrophic bee declines. Twenty-nine independent scientists who recently conducted a global review of more than 1,000 independent studies on neonicotinoids found overwhelming evidence linking neonicotinoid pesticides to declines of bees, birds, earthworms, butterflies and other wildlife.
The White House Pollinator Health Task Force is expected this spring to issue recommendations on improving the outlook for declining native pollinators. Earlier this year, more than 125 farmer, food safety, beekeeper, faith and environmental groups sent a letter to President Obama urging a moratorium on all neonicotinoids and other systemic pesticides. More than 4 million Americans have signed petitions urging the Obama administration to take immediate action on bee-toxic pesticides.