A pesticide is a chemical used to control, to repel, to attract or to kill pests, for example, insects, weeds, birds, mammals, fish, or microbes, considered a nuisance.
Examples of pesticidexs :
- herbicides for destruction or development prevention of weeds
- fongicides[?] for destruction or development prevention of fungi (example, QoI)
- insecticides for destruction or development prevention of insects
- Growth regulators[?] to prevent excess growth of a plant (prevention of lodging in wheat)
- molluscicides[?] (against snails...)
- acaricides[?] against acari
- products favoring plant resistance...
Chemical engineers develop new pesticides continually as insects grow resistant to older chemicals with steady use, requiring ever increasing dosages.
DDT is an example of a heavily used and misused pesticide.
Gene engineering plants (corn) to create and emit their own pesticides has become controversial with revelations of gene engineered corn contaminating U.S. food supplies in late 90s.