By P.J. Huffstutter CHICAGO (Reuters) - An insecticide widely used on cotton plants and citrus groves can harm bees that come into contact with those crops under certain conditions, the U.S. Environmental Protection Agency said on Wednesday. The agency said a preliminary risk assessment of imidacloprid, a neonicotinoid insecticide chemically similar to nicotine, found that chemical residues of more than 25 parts per billion would likely harm bees and their hives and result in the bees producing less honey. The EPA, which collaborated with California's Department of Pesticide Regulation, said data showed imidacloprid residues in pollen and nectar above that threshold level in citrus and cotton crops. But residues found on corn and leafy vegetables were below at-risk levels, the agency said. Some crops needed more testing. The federal agency is expected to finalize a broader assessment of risks the chemical may pose to pollinators by the end of the year. Debate over neonicotinoids, also known as neonics, has intensified as concern grows over the health of pollinators crucial to the production of many foods. A two-year moratorium on imidacloprid and two other neonics took effect in Europe last year. The EPA proposed a rule last year to create temporary pesticide-free zones when crops are in bloom and farmers are using commercial pollinators such as bees.
