Abstract: The dynamics and population characteristics of C. medinalis for each generation in the rice growing region of northern Guangdong Province were studied through systematic investigation and female ovarian dissection during 2010 and 2011, and the annual population dynamics were analyzed in combination with data from daily field surveys conducted between 1961-1976 and the recent years after 2000. The results were as follows: 1) with six generations per year in Shaoguan City, C. medinalis had two main density peaks which occurred in early and middle June on earlyseason doublecropping  paddy field, and in late August and early September on lateseason doublecropping  paddy field; 2) the population characteristics of C. medinalis for each generation were determined; 3) the date of moth density peak between 1961-1976 and 2000-2011 had no significant difference, but since 2000, mean daily amount of C. medinalis was significantly higher than that in peak days of early rice from 1961 to 1976 in Qujiang District, Guangdong Province; 4) the occurrence frequency of the highest moth density peak in earlyseason doublecropping  paddy field was higher than that in lateseason doublecropping  paddy field between 2000 and 2011 in Qujiang District, Guangdong Province. The 3rd generation and 6th generation were the major injurious generation of early rice and late rice respectively, whereas the 2nd generation and 7th generation might broke out in special years. Therefore, the enormous increase of the spring immigrants of C. medinalis was the key factor behind the successive outbreak and serious damage in northern Guangdong Province after 2003, while autumn return migration was influenced by the natural environment and human prevention in the rice growing area of northern China, and there were no relationships between the spring immigrants and the autumn return immigrants of C. medinalis.

Key words: rice growing region of northern Guangdong Province, Cnaphalocrocis medinalis (Guenée), occurence, population characteristics, peak day

摘要： 采用田间系统赶蛾、雌蛾卵巢解剖的方法研究了2010-2011年韶关地区稻纵卷叶螟的种群动态及各发生世代的虫源性质，并结合1961-1976年、2000-2011年曲江地区稻纵卷叶螟高峰日和高峰日蛾量，分析了不同年份稻纵卷叶螟田间种群消长的差异性。1）韶关地区稻纵卷叶螟一年可发生6个世代，早稻发蛾高峰期集中在6月上中旬，晚稻发蛾高峰期集中在8月底至9月上旬；2）明确了韶关地区稻纵卷叶螟各发生世代的虫源性质；3）在1961-1976年和2000-2011年两个时间段之间，曲江地区稻纵卷叶螟早稻和晚稻田间蛾量高峰日差异不显著，但2000年以来早稻田间高峰日平均蛾量却显著高于20世纪60-70年代；4）2000-2011年，曲江地区稻纵卷叶螟田间蛾量的最高峰在早稻期间的出现频率高于晚稻，早稻和晚稻的主害代分别为第3代和第6代，但个别年份第2代、第7代稻纵卷叶螟也会暴发成灾。可见，2003年全国稻纵卷叶螟大暴发以来，前期迁入蛾量的成倍增加直接导致了粤北地区早稻稻纵卷叶螟连年大发生，而秋季回迁虫源则受北方稻区的自然环境和人为防治因素的干扰，与前期迁入量之间并没有必然的联系。

关键词: 粤北稻区, 稻纵卷叶螟, 发生, 虫源性质, 高峰日