Final answer:
The Environmental Protection Agency (EPA) is responsible for pesticide regulation and licensing in the United States, operating under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).
Step-by-step explanation:
The state agency that is responsible for pesticide regulation, including licensing, is the Environmental Protection Agency (EPA).
The EPA administers the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), which predates the agency and is the legal backbone for pesticide registration in the United States. The EPA has the authority to enforce federal standards concerning environmental protection, which includes the regulation of pesticides. While the EPA is a federal agency, state departments of agriculture often work in conjunction with the EPA to handle local enforcement and inspections.