The Application Study Of The Sex Pheromone Of Controlling Tobacco Spodoptera Litura

The tobacco cutworm, Spodoptera litura, is an economically important pest in Yunnan’s Yuxi tobacco planting regions. In the past, farmers mainly adopted chemicals to control this pest. However, the long-term and overuse of chemical insecticides has led lots of environmental and health issues. It is very urgent to find effective alternatives to manage this cutworm. Sex pheromone has been widely applied in agricultural or forest pest management due to non-pollution, high efficacy and specificity. In this study, use of sex pheromone to control Spodoptera litura was comprehensively studied in Hongta District of Yuxi Prefecture. The results could be helpful to the large-scale application of sex pheromone for control of Spodoptera litura in tobacco fields. The main results as follows:1) A three-year study showed that Spodoptera litura adults can be captured in the whole year by using sex pheromone. However, the number at peak time and amount number of moths varied in different years. Based on the occurrence of cutworms and the tobacco production conditions, the time after transplantation of tobacco seedlings (early of May) could be optimum for fixing traps. Moreover, climatic factors may also affect the capture effects and should be also monitored during the application of sex pheromone.2) Capture effects of different sex pheromone lures for three main lepidopteran pests have been examined. The results showed that sex pheromone can attract Agrotis ypsilon, Heliothis assulta and Spodoptera litura. However, sex pheromone of Spodoptera litura presented a higher capture effects and could be applied into practice.3) Capture effects of different products of sex pheromone for Spodoptera litura were investigated. Lure A, produced by Newkong, Ningbo Ltd., performed a better efficacy than Lure B (Yinge’er, Xiamen) and Lure C (Zhongjie, Beijing), suggesting Lure A could be more suitable in Yuxi’s Hongta Tobacco region.4) The fixing techniques for application of sex pheromone to control Spodoptera litura have been specifically studied. The results showed that the height, location and directions of traps could affect the capture effects. Associated with the growth season of taobacco, the occurrence of Spodoptera litura and practical operations, it was suggested that the fixing height of traps could be80cm and moreover, the local conditions should also been considered before the fixing of traps (etc. directions and densities of traps).5) In Hongta District of Yuxi, the application of sex pheromone for control of Spodoptera litura had covered1,040ha accumulatively. The results showed that use of sex pheromone could attract mass of moths, decrease the density, damage rates and egg mass of Spodoptera litura, and further reduce the use of chemical pesticides and its costs, the pesticide residue in tobacco leaves and increase the quality and safety of tobacco. The comprehensive benefit analysis showed that compared to chemical control, use of sex pheromone could reduce the pest management cost by18.7RMB per mu, presenting a good economic benefit. These suggested that use of sex pheromone for Spodoptera litura control can be an effective pesticide alternative and very potential for wide application.