稻螟赤眼蜂田间自然繁殖利用研究

多年调查表明，稻螟赤眼蜂是我省多择性卵寄生天敌的优势种．同时发现．稻螟蛉卵可认为是水稻上几种主要害虫天敌的天然优良寄主．由于它的被寄生率高．天敌繁殖量大．控制后继害虫的功效显，所以在水稻生产上稻螟蛉实是益大于害的．在早稻害虫防治实践中．应该减少农药使用，或避开天敌活动期和早稻前期用药．以使世代短的天敌，在近期内迅速形成庞大的种群数量。控制相继发生的二化螟、稻纵卷叶螟和稻苞虫的为害．可减少早稻用药1-2次．上述方案．无须人工生产天敌，即以田间自然繁殖保护天敌的新技术，所能达到稻田以虫治虫的功效．不亚于以往工业生产天敌的举措．实具有经济、生态和社会三方面的效益．

THE UTILIZATION OF NATURAL PROPAGATION OF TRICHOGRAMMA JAPONICUM ASHMEAD IN FIELDS

For many years investigations indicate that Trichogramma japonicum is a dominant species of multi-host egg parasite in Jiangxi,and eggs of Naranga aenescens Moore can be thought as an excellent host for natural enemics of several main rice pests.Because of its high rate for being parasitized,eggs of N. aenescens Moore are favorable for the propagation of natural enemies,which results in good control of the succeeding pests.Therefore,its benefit outweighs its harm.In pest control practice,we should decrease appli- cation of pesticides and avoid applying pesticides at the active stage of natural enemies or at the early stage of rice growth to allow natural enemies to produce great population rapidly for controlling the succeeding pests Chiio suppressalis(Walker),Cnaphaiocris medinalis Guenee and Parnara guttata Bremer et Grey.One or two applications of pesticides can be saved to early rice.The above method,having no artificial propagation of natural enemies,is a breakthrough from traditional industrial production to natural propagation in fields.It has economic,ecological and social benefits.