not include any article that is a ‘new animal drug' within the meaning of section 201(w) of the Federal Food, Drug, and Cosmetic Act (31 USD 321 (w)), that has been determined by the Secretary of Health and Human Services not to be a new animal drug by a regulation establishing conditions of use for the article, or that is an animal feed.” What can be considered a pesticide is determined in part by what is specified as a pest. According to FIFRA, “an organism is declared to be a pest under circumstances that make it deleterious to man or the environment.” FIFRA also lays out the foundation for the regulation of pesticides by the federal government: according to the July 1, 1997, edition of FIFRA, as amended, “no person may distribute or sell any pesticide product that is not registered under the act except as provided in (152.20, 152.25 and 152.30).” Pesticides are regulated by three federal agencies: the US Department of Agriculture (USDA), the Environmental Protection Agency (EPA), and the Food and Drug Administration (FDA).
Although the legal definition of a pesticide might appear straightforward, its biological underpinnings are tenuous at best. Among the most important complications is the broad definition of pest itself, a term with no biological validity (Newsome, 1967). Simply put, a pest is any organism that appears in a place where it is unwelcome, and unwelcome is defined in strictly human terms. Pest status does not adhere to taxonomic lines; some families of insects, for example, have members that are pest species and others that are regarded as beneficial (the beetle family Coccinellidae, for example, includes economically damaging herbivorous crop pests and predaceous biological control agents). By the same token, some species are regarded as an economic boon in some localities and a bane in others. Even in the same locality, different constituencies might regard the same species from different perspectives. In some parts of the southern United States, for example, Johnsongrass is considered a noxious weed by crop producers and an important component of dove habitat by hunters. Clearly, the same species of plant can be a crop or a weed, depending on circumstances. The fact that little if any taxonomic consistency underlies pest status suggests that selectivity for pest species, generally considered a positive attribute of a pesticide, is unlikely to be achieved easily.
Confusion in the general public as to the nature and origin of pesticides is a reflection of inconsistencies in usage among various constituencies. According to FIFRA, substances that repel but do not kill pests and substances that mitigate pest problems are considered pesticides—a designation that is neither intuitive nor etymologically consistent. Moreover, in a legal context, origins serve as the basis of differentiation. According to EPA, for example, substances produced naturally by plants to defend against insects and pathogenic microbes—and the genetic material re-