Analysis on the causes of recent outbreaks of Cnaphalocrocis medinalis in Nanning, China.

摘要: The population feature and source areas of the rice leaffolder,Cnaphalocrocis medinalis(Guenee) on early-season in Nanning,Guangxi Zhuang Autonomous Region,China were studied through systematic field survey,dissection female ovarian,trajectory analysis,synoptic analysis historical data analysis.The results indicated that possible major immigrant populations C.medinalis Nanning,China 2007 northern parts Vietnam,and central Laos Thailand.The amount date spring immigration April-May autumn return migration their relationships with rainfall rainy days between 1970-1980 recent years after 2000 compared.It was found enormous increase immigrants earlier appearance main causes for consecutive outbreaks serious damages 2003.There no migration,neither its nor date.