稻田中性昆虫对群落食物网的调控作用

STUDIES ON THE REGULATION EFFECT OF NEUTRAL INSECT ON THE COMMUNITY FOOD WEB IN PADDY FIELD

本文把稻田既非害虫也非无敌的一类昆虫称为中性昆虫，应用选择性控制法（扑虱灵和杀蚊幼剂－ＢＳ）、挤压法、脉冲试验法及通径分析研究了稻田中性昆虫的调控作用；中性昆虫与天敌、害虫的直接和间接作用规律。结果证明中性昆虫数量减少害虫数量增加，中性昆虫与害虫呈显著的负相关、与天敌呈显著的正相关。中性昆虫对害虫的调控主要是通过影响捕食性天敌而实现的。

group of insects other than both insect pests and natural enemies,such as dominantmosquito(adult and larva)and collembola in paddy field,was defined as the neutral insects inthis paper.The regulation effects of the neutral insects on the community food web in paddyfields,as well as direct and indirect relationships among the neutral insects,predators andpests,were studied by using the press and the pulse experiment designs and some selectivecontrol methods with buprofezin to control plant hoppers and with Bacillus sphaericus to killlarvae of mosquito. The results showed that pest increased as decrease of the neutral insectabundance,while predator abundance increased as increase of the insect abundance。The regu-lation effects of the neutral insects on pest abundance were mainly realized by predators。