A new study by Penn State University revealed how pervasive the application of neonicotinoids is to harm pollinators. The use of these pesticides was driven almost entirely by the use of corn and soybean seeds treated with this particular type of pesticide and neonicotinoid seed treatments were not explicitly documented in U.S. government pesticide surveys.
The European union has suspended the use of neonicotioid crops on bee-attractive crops and the Obama administration has put together a task force to investigate the impact of these pesticides on pollinators. “Previous studies suggested that the percentage of corn acres treated with insecticides decreased during the 2000s, but once we took seed treatments into account we found the opposite pattern,” said Margaret Douglas, graduate student in entomology. “Our results show that application of neonicotinoids to seed of corn and soybeans has driven a major surge in the U.S. cropland treated with insecticides since the mid-2000s.”
The study consisted of analyzing available information to characterize the widespread use of these insecticides. First they compiled pesticide data from two public sources — the U.S. Geological Survey and the U.S. Department of Agriculture — that both reported aspects of neonicotinoid use, but did not estimate seed treatment use specifically. Using these data, together with information from insecticide product labels, the team estimated the percentage of land planted in corn and soybeans in which neonicotinoid-treated seeds have been used since these products were introduced in the mid-2000s. They corroborated their results with information from the U.S. Environmental Protection Agency and DuPont Pioneer, a major seed supplier. The research findings revealed that in 2000, less than 5 percent of soybean acres and less than 30 percent of corn acres were treated with an insecticide, but by 2011, at least a third of all soybean acres and at least 79 percent of all corn acres were planted with neonicotinoid-coated seed, constituting a significant expansion in insecticide use.
“Regulators, seed companies, farmers and the public are weighing the costs and benefits of neonicotinoid use,” said Douglas. “This debate has been happening in a void of basic information about when, where and how neonicotinoids are used. Our work is holding up a mirror so that this conversation can be informed by basic facts about neonicotinoid use.”
Margaret Douglas, John F Tooker. Large-scale deployment of seed treatments has driven rapid increase in use of neonicotinoid insecticides and preemptive pest management in U.S. field crops. Environmental Science & Technology, 2015; 150320174253000 DOI: 10.1021/es506141g