ABSTRACT
Generally, the term “pest” refers to any insect, rodent, nematode, fungus, weed, or any other form of terrestrial or aquatic plant, animal, virus, bacteria, or other microorganisms that harm the garden plants, trees, foodstuffs, household articles, or is a vector of diseases. However, for farmers, pests include insects and mites that feed on crops; weeds in the elds; aquatic plants that clog irrigation and damage ditches; agents that cause plant diseases such as fungi, bacteria, viruses, nematodes, snails, slugs, and rodents that consume enormous quantities of plant seedlings and grains. George
Ware, a well-known environmentalist, de ned the term “pesticides” as man’s intentional additives to improve his environment quality for himself, his animals, and his plants. A pesticide can be used against any form of terrestrial and aquatic plant, animal, or microorganism, which an agency declares as a pest. However, in general, it may be de ned as a substance that exerts toxic action on the pests. Owing to the wide diversity, it is really a dif cult task to provide a general scheme for the classi cation of various pesticides. However, pesticides are classi ed, based on their evolution process, mode of action, chemical nature, and target species. Figure 3.1 presents a schematic view of categorization of pesticides into different classes.
