As a result of the green revolution, the use of yield-increasing inputs such as fer tilizer and pesticides became a matter of course in irrigated rice farming in Southeast Asia. Pesticides were applied liberally, both as a guarantee against crop failure and as a means of fully utilizing the existing yield potential of the crops. However, since outbreaks of pests, such as the brown planthopper (BPH) or the tungro virus, continued to occur despite the application of chemicals, a change of approach began to take place. It is now being realized more and more in Southeast Asia that crop protection...