The brown planthopper problem.

The brown planthopper Nilaparvata lugens (Stal) recently increased in abundance and caused severe yield losses in several tropical countries of Asia. It is rather widely distributed but is found mainly in South, Southeast, and East Asia. It damages the rice plant by directly feeding on it and by transmitting the grassy stunt disease. Some damage by the brown planthopper has been reported in Bangladesh, Brunei, China, Fiji, Korea, Malaysia, Papua New Guinea, Solomon Islands, Sri Lanka, Thailand, and Vietnam. But according to available data, the most extensive losses from the insect and the disease have occurred in India (estimated at US $ 20 million), Indonesia (US $ 100 million), and the Philippines (US $ 26 million). Losses from the insect alone are US $ 100 million in Japan and US $ 50 million in Taiwan. The estimated losses due to the brown planthopper and the grassy stunt disease total more than US $ 300 million. That is a conservative estimate; it includes only losses from reporting countries and excludes expenditures for control operations. A pest management strategy that is compatible with modern rice technology is urgently needed to solve this serious pest problem.