This rule establishes time-limited tolerances for residues of the insecticide 1-[(6-chloro-3-pyridinyl)methyl]-N-nitro-2- imidazolidinimine (also known as imidacloprid) and its metabolites in or on barley forage, straw, and grain with an expiration date of 3 years after its effective date. Gustafson, Inc., submitted a petition under the Federal Food, Drug and Cosmetic Act (FFDCA) that requested this regulation to establish these maximum permissible levels for residues of the insecticide.