The Use of Natural Enemies for Controlling Pests for Estate Crops

Abstract

Pests is one of the constraints faced by estate holders in the management of their crops. The attack of Helopeltis antonii and Zeuzera coffeae on cocoa and tea, Hypothenemus hampei on coffee, Heteropsylla cubana on Leucaena as a shading tree, and Setora nitens or Setothosea asigna on oil palm are among the examples of the problem. The use of insecticides is the most common method for controlling those problems. Eventhough the technique is effective, there are some drawbacks of using insecticides such as environmental'pollution. In order to cope with the problem, the use of natural enemies e.g. fungi, virus, bacteria, predator or parasitoid which is relatively inexpensive and safe for the environment could be developed. The use of a solution containing spores of Beauveria bassiana for controlling Z. coffeae on cocoa proved to give a good result. The same result was also obtained on the use of a crude extract of virus isolated from infected larvae to suppres the population of S. nitens or S. asigna. In addition, the application of Curinus coeruleus, introduced from Hawaii, for controlling Leucaena psyllid on Leucaena as a shading-tree had also been successful. The development of the use of B. bassiana for controlling H. antonii on cocoa, and for H, hampei on coffee had been carried out. The application of parasitoid, Cephalonomia stephanoderis, introduced from Africa, for controlling H. hampei; and parasitoid Psyllaephagus yaseeni, introduced from Thailand, for controlling Leucaena psyllid are beeing studied.