菜田节肢动物群落特征及其多样性恢复的研究

探讨了化学杀虫剂对菜田节肢动物群落结构和多样性的影响以及停止化学杀虫剂使用后多样性的恢复，结果表明化学杀虫剂对菜田节肢动物群落的物种组成，多样性指数及物种分布的均匀性等均有影响，菜田节肢动物群落结构变化同害虫类，捕食性天敌和蜘蛛类的特征变化关系密切，经常使用化学杀虫剂的菜田与停止使用后的菜田相比，物种数量显减少，多样性指数降低，停止化学杀虫剂使用后，优势害虫的种群趋势指数明显降低，大敌对主要害虫的控制作用增强，节肢动物多样性指数增大，因此，限制化学杀虫剂的使用，恢复由于化学杀虫剂的使用而破坏了菜田环境，增强天敌对主要害虫的控制能力，这在菜田害虫生态控制中起着重要的作用。

CHARACTERISTICS OF ARTHROPOD COMMUNITY AND THEIR DIVERSITY RESTORATION IN LEAFY VEGETABLE FIELDS

The effect of chemical insecticides on the structure and diversity of arthropod communities in various vegetable fields and the restoration of their biodiversity after stopping application of chemical insecticides were studied. The results showed that the effect of chemical insecticides on the arthropods in vegetable fields could be characterized the species structure, the diversity index and the evenness of species distribution. Components of arthropod species depended closely on the species number of insect pests, predatory natural enemies and spiders. Investigations showed that the numbers of species in the vegetable fields managed with chemical insecticides were obviously reduced, and their diversity indices were lower comparing with that without chemical insecticides. When the applications of chemical insecticides were stopped in vegetable fields, the index of population trend ( I ) of dominant insect pests decreased greatly, the control effect of natural enemies on major insect pests increased, and the diversity index of arthropod increased at the same time. Thus, limiting the application of chemical insecticides, resuming the environment of vegetable fields destroyed by using chemical insecticides, escalating the control ability of natural enemies on main insect pests will play an important role in the ecological control of insect pests in vegetable fields.