Insect and disease control law deals with plant pests and noxious weeds. A plant pest is defined as any living stage of any insects, mites, nematodes, slugs, snails, protozoa, or other invertebrate animals, bacteria, fungi, other parasitic plants or reproductive parts thereof, or viruses, or any similar organisms of the foregoing, or any infectious substances which can directly or indirectly injure or cause disease or damage in any plants or parts or products thereof and which may be a serious agricultural or horticultural threat. A noxious weed is defined as any living stage, including, but not limited to, seeds and productive parts of a parasitic or other plant of a kind, or subdivision of a kind, which may be a serious agricultural threat.
At the state level, statutes may exist to provide for the inspection and control of nurseries and the regulation of the sale and distribution of plants and plant products. Such statutes also aim to prevent the importation of plant pests and noxious weeds into its borders.