ABSTRACT
Insects are numerous invertebrate animals of the class Insecta. In the adult stage, insects are characterized by having six legs (three pairs) and a segmented body which usually is winged. Various similar invertebrate animals, such as, spiders, mites, ticks, millipedes, and centipedes, which are not taxonomically insects, are defined loosely as insects in common terminology by the public. Control of these organisms often is considered under topics of insect control. Pathogenic nematodes, which are microscopic worms, usually are studied as plant diseases.
