田边杂草中捕食性生物与稻田飞虱及其捕食性天敌的相关分析

1984～1985年在福建闽侯对田边杂草中捕食性生物与稻田飞虱及其捕食性天敌的相关性进行了初步的研究。得知山边、沟边、田埂等田边杂草中捕食性天敌的资源十分丰富,有蜘蛛类、步甲类、隐翅虫类、蚂蚁类等,这些类群中的多数种类与稻田捕食性天敌的种类相同,均能捕食飞虱。山边和沟边杂草中益害比为6.61～11.62∶1,田埂杂草中益害比为0.83∶1。蜘蛛是田边杂草中常见的捕食性生物,也是稻田捕食性天敌的优势类群,两者具有明显的相关,对稻田飞虱的自然控制作用显著。此外,田边杂草中的另一些捕食性生物,它们在控制水稻害虫总体上,也都起到不同程度的辅助作用。保护利用田边杂草中的害虫天敌资源,对于维护以水稻为中心的农田生态系统,保持自然平衡,具有重要意义。

AN INTERRELATIONSHIP SURVEY ON RICE PLANTHOPPERS PREDATORS OF THE WEEDS AROUND THE RICE FIELDS

The authors conducted an interrelationship survey on rice planthoppers predators of the weeds around the rice fields in Minhou of Fujian Province in 1984-85.The predators appeared on the weeds nearby to the rice fields were plenty in number and species mostly found on the hillsides,banks of ditches and rice field ridges.They included spiders,carabid beetles, rove beetles and ants.Most of them were predatory species against plant- hoppers similar to those found in the rice fields.The ratio between natural enemies and insect pests on the weeds of hillsides and banks of ditches was 6.61:1 up to 11.62:,and 0.83:1 on the rice field ridges.Among them,the most commonly fouund and such predators in the rice fields were not only dominant in number but also intimately connected with the hosts.They checked the rice planthoppers notably.Furthermore,other predators existed on the weeds nearby to the rice fields also played the sup- plementary role in controlling the rice insect pests.Thus,protection and utillization of the natural enemies on the weeds around the rice fields is of most significant importance in maintaining the ecosystem of rice cultiva- tion and the ecologic balance of the biosphere.