ABSTRACT
The developmental life cycles of insects commonly undergo changes in form called metamorphosis. The cycle for all insects begins with an egg. The egg hatches into an immature insect stage called a larva. The larvae are known commonly as worms, grubs, caterpillars, maggots, or nymphs depending on whether the final stage is called a moth, wasp, butterfly, fly, bug, beetle, or perhaps other name. As the larvae grow, they feed heavily on their hosts. Larval stages of insects often are the most ruinous to crops because of the heavy feeding to support the growth of these organisms. Larvae have limited capabilities to travel and spend their life stage on one or a few plants. Larvae shed their skin several times until they reach maximum size. At the end of the growth of the larval stage, many insects form a legless, compact stage called a pupa. The pupal stage is a sort of resting or dormant stage and has a hard protective outer case, sometimes with a cocoon-like structure. The adult grows from the pupa, and when mature, the adult splits from the pupal case. The adult is a fly, a moth, a butterfly, a beetle, or other winged or unwinged form of the organism. Winged adults have considerable capacities to travel. The feeding habits of the adults may resemble or differ widely from those of the larvae. Control of insects requires that the grower recognize whether the larvae or adults are the main feeding pests of plants.
