Eggplant Integrated Pest Management AN ECOLOGICAL GUIDE

_____________________________________________________________________Ecology of insect pests and natural enemiesInsects have:As simple as it may seem, knowing what type of mouthparts an insect has can be important in decidingon a management tactic. For example, insects with chewing mouthparts can be selectively controlled bysome insecticides that are applied directly to plant surfaces and are only effective if ingested; contactalone will not result in death of the insect. Consequently, natural enemies that feed on other insects, butnot the crop plant, will not be harmed.4.3 Insect Life CyclesInsect life cycles can be complete or incomplete(gradual). In complete life cycles, or better: life cycleswith a complete metamorphosis, insects pass throughthe egg, larval, pupal and adult stage. A larva is a younginsect that looks very different from the adult. Larvaemay also behave differently from the adults. There aregenerally several larval stages (also called instars). Eachlarval stage is a bit larger than the previous stage,requiring a molting or shed of the outer skin between thestages. Complete life cycles can be found with moths,butterflies, beetles, flies and wasps.In incomplete life cycles, or better: life cycles with anincomplete metamorphosis, insects go through egg,nymph and adult stage. There are generally severalComplete metamorphosis: ladybeetle:egg, 4 larval stages, pupa, adult(from: Hoffmann, 1993)49Eggplant Ecological Guide