Possible Impacts of Climate Change on Rice Insect Pests and Management Tactics in Taiwan

Abstract

Climate change may have an effect on all organisms, including plants, insects and their interactions among weather, plants and herbivores. Moreover, the insect physiology, behavior, development and species distribution may also be affected in a changing climate. On the other hand, the population abundance of an insect species is manipulated by the host plant, natural enemies or extreme weather conditions. The current warming trend may drive the climate pattern of Taiwan from subtropics to tropics in the future, and provide more suitable conditions for propagations of most rice insect pests excluding those of obligatory univoltine. At present, the impacts of climate change on insect pests are not clear and unpredictable. The successive monitoring changes in pests’ population in the paddy fields is a priority job for pest control. Once the key insect pests have been identified, the follow-up control measure can be set-up and apply at right place in the right time. Concluding from the experience and research findings in either tropical or temperate region, the integrated pest control system incorporating cultural and biological control is still the best tactics for lower down pest populations under acceptable levels. Pesticides are used only when they are needed. 氣候變遷可能影響包含植物、昆蟲等之各種生物，以及氣候因子與植物及其與植食性昆蟲之間的相互作用，全球溫暖化亦將直接影響昆蟲之生理、行為、發育及分布。每一昆蟲族群之豐度，則受到其寄主植物、天敵及極端天氣等因素之直接或間接影響。溫度為環境因子中之重要因素之一，在暖化的氣候變遷趨勢下，臺灣的氣候環境可能由亞熱帶逐漸走向熱帶氣候，如此使得提供一年一世代寡食性昆蟲以外的大部分水稻害蟲更適合發育及繁殖。雖然目前全球氣候變遷對害蟲的影響仍模糊不清，而且無法準確預測，惟持續性監測水稻害蟲發生種類及族群變動依舊是一項優先且重要之工作。當水稻重要害蟲種類確定之後，適當的防治措施即可隨著修正、改進。吾人從水稻害蟲的防治經驗及熱（溫）帶地區的蟲害防治研究，發現以結合耕作及生物防治的綜合防治體系仍為抑制害蟲族群於可接受水準之最佳策略，化學除蟲藥劑僅在需要時適時施用即可。