A material useful for the mitigation, control, or elimination of plants or animals detrimental to human health or economy. Algicides, defoliants, desiccants, herbicides, plant growth regulators, and fungicides are used to regulate populations of undesirable plants which compete with or parasitize crop or ornamental plants. Attractants, insecticides, miticides, acaricides, molluscicides, nematocides, repellants, and rodenticides are used principally to reduce parasitism and disease transmission in domestic animals, the loss of crop plants, the destruction of processed food, textile, and wood products, and parasitism and disease transmission in humans. Some pesticides are obtained from plants and minerals. Examples include the insecticides cryolite, a mineral, and nicotine, rotenone, and the pyrethrins which are extracted from plants. A few pesticides are obtained by the mass culture of microorganisms. Two examples are the toxin produced by Bacillus thuringiensis, which is active against moth and butterfly larvae, and the so-called milky disease of the Japanese beetle produced by the spores of B. popilliae. Most pesticides, however, are products which are chemically manufactured. Two outstanding examples are the insecticide DDT and the herbicide 2,4-D. Concern over the undesirable effects of pesticides on nonpest organisms culminated in laws to prevent exposure of either humans or the environment to unreasonable hazard from pesticides through rigorous registration procedures. The purpose of regulations are to classify pesticides for general or restricted use as a function of acute toxicity, to certify the qualifications of users of restricted pesticides, to identify accurately and label pesticide products, and to ensure proper and safe use of pesticides. Recommendations as to the product and method of choice for control of any pest problem—weed, insect, or varmint—are best obtained from county or state agricultural extension specialists. Sophisticated methods of pest control are continually being developed. Highly specific synthetic insect hormones are being developed. In an increasing number of pest situations, a natural predator of an insect has been introduced, or conditions are maintained that favor the propagation of the predator. The numbers of the potential pest species are thereby maintained below a critical threshold. An insect control program in which use of insecticides is only one aspect of a strategy based on ecologically sound measures is known as integrated pest management. Agricultural chemistry Chemical ecology Fungistat and fungicide Herbicide Insect control, biological Insecticide |
