Progress in research on prevention and control of beet armyworm,Spodoptera exigua in China

The beet armyworm (BAW),Spodoptera exigua (Hubner),is a rampant pest in intensive vegetable cultivation in China,with high resistance to control methods.The occurrence,over-wintering,migration,resistance,biological control and integrated pest management (IPM) of this species were systematically studied.The results indicate that the period of occurrence forms a wedge shape from south to north.The population sizes attained form a saddle-shape,with higher populations in central China and lower populations in the south and north.We used flight mills to investigate the interaction between flight and reproduction in this species given the apparent absence of the oogenesis-flight syndrome.We showed that the migration of BAW is of relay-type and moves seasonally from north to south and we made a preliminary clarification of the route and timing of BAW in East China.The over-wintering areas of BAW were predicted and identified nationally.We clarified levels of resistance to ten insecticides in major occurrence areas and measured resistance risk,cross-resistance,population fitness,resistance inheritance,resistance mechanisms and resistance management of BAW to indoxacarb and emamectin benzoate.The effectiveness of seven efficient and environmentally friendly pesticides were screened in field trials in Hainan,Hunan,Hubei,Shanghai and Tianjin,achieving significant results.We successfully developed artificial propagation techniques for Snellenius manilae (Ashmead),Telenomus remus Nixon and Microplitis pallidipes Szepligeti,and improved the production process for S.exigua nuclear polyhedrosis virus (SeNPV),solving key technological problems to achieve the large-scale production and field emancipation of these parasitoids and SeNPV.The formula of a sex attractant for BAW has been optimized and a new trapping device invented and these are now available on the market.We integrated four simple and practical technologies and developed prevention and control programs to suit the different characteristics of each of South,North,Central and East China.During project implementation,sixteen test and twenty-nine core model bases have been established in areas of major occurrence and about 3 800 hm2per year treated for demonstration.Obvious economic,ecological and social benefits have followed.