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本文根据湘北 4 9年水稻三化螟 Tryporyza incertulas( Walker)种群密度消长的历史资料 ,着重分析了 1996～ 1998年连续 3年三化螟在湘北猖獗为害的原因 ,即中稻、一季晚稻面积增加 ,杂交中、晚稻“双两大”的推广 ,晚稻的大面积早插都便于三化螟辗转繁殖为害 ;稻田春收作物——油菜的大面积种植 ,增加了三化螟的有效越冬虫源 ;水稻播期拉长及品种的多元化和栽培方式的多样化 ,使水稻危险生育期与蚁螟盛孵期吻合度加大 ;三化螟对农药的抗性增强和主害代发生期变得不整齐 ,增加了防治的难度
Based on the historical data of the population density of Tryporyza incertulas (Walker) in the 49th year in the north of Hunan Province, this paper mainly analyzed the reason why the stem borer was rampant in the northern part of Hunan Province from 1996 to 1998 for three consecutive years. That is, Hybridization, the late rice “double big two” promotion, late rice large early assert are easy for the stem borer breeding tampering; paddy field spring crops - rape large-scale planting, an increase of effective access to three borer insect overwintering source; The prolonged sowing date of rice and diversification of cultivars and cultivation methods make it more coincidental with the growth of rice stem borers at the risk of developing stage. The resistance of the stem borer to pesticides and the occurrence of the main damaging stage become Unregular, increasing the difficulty of prevention and treatment