PEST-MANAGEMENT SYSTEMS FOR EGGPLANT ARTHROPODS - A PLAN TO CONTROL PEST RESURGENCE RESULTING FROM THE DESTRUCTION OF NATURAL ENEMIES

Eggplants in an experimental plot were continuously sprayed with the insecticides permethrin, milbemectin, phenthoate and imidacloprid to evaluate their respective side-effects. Effects on populations of pests and of their natural enemies were assessed. The results revealed the importance of natural enemies such as anthocorid bugs, Orius spp. Application of a pesticide may cause a resurgence of a pest population because of (1) the development of resistance by the pest and (2) nonselective killing of predators. The author therefore attempted to develop methods of control of pests that would not affect substantially natural enemies. Imidacloprid which is highly effective against the pests Hemiptera and T. palmi caused a resurgence of the spider mite. Milbemectin which exerts a minimal adverse effect on Orius spp. when used in combination with imidacloprid, maximized the latter's advantages while minimizing its disadvantages.