What is a pesticide?
September 4, 2012
University of Nevada Cooperative Extension recently completed a survey of residents to assess their knowledge and use of pesticides. One question asked “How often do you use weed-and-feed-type products?” Fifty-six percent of residents from Carson City apply them from one to six times per year. The next question was “How often are pesticides applied on your lawn?” “Never” and “seldom” (once per year or less) were the responses given by 94 percent of participants. In one question over half said they applied weed-and-feed products up to six times per year and then almost 100 percent stated they rarely, if ever, applied pesticides to their lawn. It appears many people do not realize that weed-and-feed-type combinations are primarily pesticides with small amounts of added fertilizer. Often people don’t understand what a pesticide is, thinking it is something more toxic than products they regularly use in their daily lives, such as antibacterial soap, bleach and, yes, weed and feed. A pesticide is a compound that prevents, destroys, repels or mitigates a pest. Antibacterial means it kills bacteria. Bleach is considered a pesticide when it is used to disinfect (kill microbes). Weed-and-feed-type products contain herbicides that kill weeds in a lawn. Fungicides kill fungus-caused plant diseases such as powdery mildew. Insecticides kill insects, such as aphids. Rodenticides kill rodents, which include mice and ground squirrels. Pesticides can be organic or inorganic. They might be chemical or biological in nature. They can be broad-spectrum or specific in their mode of action. An example of a broad-spectrum herbicide is glyphosate (RoundUp, KleenUp etc.), which kills most green plants. A weed-and-feed-type product is a pesticide, an herbicide, with a specific target. It kills only broadleaf plants, not narrow-leafed grass plants. Many insecticides are broad-spectrum pesticides and kill not only problem insects, but also beneficial ones. Carbaryl, the active ingredient in Sevin, Adios, Carbamec, etc. is an example of a broad-spectrum chemical insecticide. An example of a specific biological insecticide is Bacillus thuringiensis variety kurstaki, which only kills leaf-eating caterpillars of the butterfly and moth family. Pesticides often benefit humans. A product that kills mosquitoes or bedbugs helps protect human health. However, pesticides can also potentially be toxic to humans and other animals. It is important always to use them safely according to label directions. Using a pesticide carries some risk, but awareness of what a pesticide is and how to use it properly, decreases that risk. JoAnne Skelly is the Carson City/Storey County Extension educator for University of Nevada Cooperative Extension and may be reached at firstname.lastname@example.org or 887-2252.