大蒜-小白菜间作套种对菜田节肢动物功能团的影响

2004年9-11月于福建省琅岐岛针对大蒜与小白菜间作(CG1)套种(CG2)对节肢动物群落功能团影响进行调查和分析。结果显示:CG1提高了植食性昆虫、寄生性和捕食性天敌丰盛度,CG2可在降低植食性昆虫数量的同时提高寄生性天敌的数量;多作田寄生性天敌物种丰富度、丰盛度和多样性指数均高于单作田;优势类群动态表现为菜蚜茧蜂与蚜虫种群在CG1出现"天敌跟随现象",多作田在整个生长期都有利于提高捕食者球腹蛛的控制效能;中性昆虫在生长前期和中期是菜蚜虫茧蜂和球腹蛛的替代寄主或猎物。因此合理的间作或套种,有利于提高菜田生境的多样化,强化自然天敌对害虫的生态控制作用。

Effects of garlic-Chinese cabbage intercropping systems on the guilds of arthropod communities in vegetable fields

Field trials were carried out at Langqi,Fujian,P.R.China,in 2004,to determine the effects of intercropping Chinese cabbage(Brassica chinensis)with garlic(Allium sativum)(CG1 and CG2)on the abundance and diversity of various arthropod guilds.The results generally demonstrated a higher abundance and diversity of herbivores,predators and parasitoids in the intererop- ping treatments.There was a higher abundance of herbivores,parasitoids and predators in CG1 than in the control(CK)and a higher abundance,richness and diversity indices of parasitoid guild were found in intercropping systems than in CK.With respect to a one species,the dynamic of the parasitoid Diaeretiella rapae M'Intosh population was followed by aphid dynamic.Next,the abun- dance of spiders from Theridiidae family,comprised of important predator species,was greater in the intercropping systems than in CK throughout the growing season.Finally,Diptera of the Ephydridae family were the ahernative preys or hosts for natural enemies. These findings suggest that intcrcropping techniques could potentially increase the efficiency of natural enemy.