Development of Integrated Control Programs for Pests of Tropical Perennial Crops in Malaysia

Abstract

Malaysia comprises two regions, West Malaysia (the former Straits Settlements and Federated Malay States), consisting of the Malayan Peninsula, and East Malaysia (the States of Sarawak and Sabah), consisting of the northern part of the island of Borneo. The country has a predominantly agricultural economy with vast areas devoted to monocultures of a range of crops. The climate is wet tropical (hot and humid). The temperature is without marked fluctuations or extremes (Dale, 1963) and rainfall occurs throughout the year (Dale, 1959). Despite the apparent favorability of this climate to their increase, a variety of potential insect pests remain at low numbers most of the time, particularly in perennial crops. Circumstantial evidence strongly suggests that this is because climatic conditions also favor a controlling balance between the pests and their insect natural enemies. On the other hand, pests can increase rapidly and continuously if this natural balance is disturbed, particularly by pesticides which, in some circumstances, may relatively favor the pest insect in the long run. Dramatic results occurred when broad-spectrum, long-residual contact insecticides were applied in both oil palms and cocoa, leading to pest explosions. This was a principal indicator of the need to deal with all these pest problems in a manner taking full account of ecological factors, supplementing and utilizing natural control agents to the fullest extent. The need for such an integrated approach to pest problems is now widely accepted and practical programs are being devised, as will be illustrated with examples taken from three major perennial crops, oil palms, cocoa and rubber. Conway (in press a) has previously discussed the problems from an ecological viewpoint.