Understanding the basics about arthropod life cycles and growth habits will help the grower grasp more complex and critical concepts of pest management. Life Cycles Insects and mites do not usually just appear in hordes that attack crops, although sometimes that may seem to be the case. Each species has its natural origins and a limited ability to increase its population. The majority of insects reproduce by laying eggs which develop outside the mother's body. Some, many aphid species for example, develop and hatch within the female's body and give the appearance of live birth.
Arthropods undergo changes as they grown and mature through a process known as metamorphosis.
Some very primitive insects change so little, other than in size, as they develop from immatures into adults that they are said to exhibit ametabolous metamorphosis. This simply means that there is almost no change in form from one stage to the next. Incomplete or gradual metamorphosis is considered the more primitive of the two. It is characterized by immature stages called nymphs, which resemble the adult stage. The insect grows larger with each new growth stage or instar, but little external change is visible.