Population trends of Chilo suppressalis during the past 20–35 years in Japan, Korea and Taiwan were compared in terms of light trap records and the area infested by Chilo. In all three countries, Chilo showed a declining population trend, first observed in the late 1950s in Japan, followed by the same pattern in Taiwan and Korea, successively. Among the contributing factors, the early planting of rice was suggested as one common factor. This early planting of rice is also followed by, or associated with, various agronomic practices, e.g. the use of varieties with a larger number of tillers, more intensive pesticide control, early harvesting, the mechanization of agricultural practices, etc. An integrated technology system based on early planting was considered the primary factor responsible for the recent decrease in Chilo. The increased utilization of machinery in rice production will encourage a further decline in Chilo in this region. Local and small scale outbreaks of Chilo were observed in all three countries, due to the widespread use of straw for the culture of special crops. However, so long as the current production system remains the same, there is no scope for Chilo's revival.