EPA Finds Popular Neonic Harmful to Bees
Imidacloprid, the ingredient that makes up nearly half of Bayer CropScience’s Gaucho, has been declared a threat to pollinators by the Environmental Protection Agency (EPA). Imidacloprid is one of many popular neonicotinoids (neonics) used as seed treatments for field crops.
A preliminary risk assessment by the EPA found that pesticide residue in the pollen and nectar produced by cotton and citrus is above the threshold level of 25 ppb set by the agency. Having a residue level above 25 ppb means pollinator hives will likely show effects of the neonicotinoid: fewer pollinators and lower honey production.
At this point, crops that don’t produce nectar, like corn and leafy vegetables, haven’t been found to have residue levels that pose a threat to pollinator hives. However, the EPA’s assessment of imidacloprid is ongoing.
“We will review the EPA document, but at first glance it appears to overestimate the potential for harmful exposures in certain crops, such as citrus and cotton, while ignoring the important benefits these products provide and management practices to protect bees,” said Bayer CropScience in its initial reply via press release.
The EPA is doing four pollinator risk assessments of neonic insecticides and will allow for a 60-day period of commentary after each assessment is officially released to the public before the agency takes any steps to reduce risks. A focus on overall hive health and effects is being stressed by the EPA. The other three assessment findings will be released in December 2016 and will focus on clothianidin, thiamethoxam, and dinotefuran.
In the U.S., neonicotinoid-treated seed is planted in more than 80% of corn acres and 40% of soybean acres. Starting in the early 2000s, these neonics became popular as seed treatments partly due to the fact that they are less toxic to mammals than other insecticides.
Neonics are water-soluble, which means they’re easily moved beyond property lines in runoff. They are also spread in planter dust as it floats beyond field borders.
“Neonics are critically important to today’s integrated pest management programs, allowing farmers to manage destructive pests, preserve beneficial insects, and protect against insect resistance,” said Bayer CropScience in a statement.