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稻纵卷叶螟过去在我省稻区属于次要害虫。近年来,随着耕作制度的改变,栽培技术的提高,使稻纵卷叶螟种群数量出现了新的变化。过去只在我省湘南、湘中及湘西部分丘陵山区间歇发生,而1969年以来逐步由南向北,发展很快,全省90多个县(市)连续四年大发生。早稻南重北轻,晚稻则相反,北重南轻,成为水稻稳产高产的主要障碍,1972年已列为我省
Cnaphalocrocis medinalis in the past in our province is a major pest insects. In recent years, with the change of cultivation system and the improvement of cultivation techniques, new changes have taken place in the population of rice leaf roller. In the past, it only intermittently occurred in some hilly areas in southern Hunan, central Hunan and western Hunan. Since 1969, it gradually developed from south to north and developed rapidly. More than 90 counties (cities) in the province have occurred for four consecutive years. Early rice south of North light, late rice, on the contrary, north of South light, rice has become a major obstacle to a stable and high yield of rice in 1972 has been listed as my province