天敌对麦蚜自然控制效能的研究

A Study on the Effecacy of Naturally Controlling Wheat Aphid

豫北冬麦区麦蚜的天敌约有8类64种,其中优势种约有七星瓢虫、黑带食蚜蝇、草间小黑蛛、蚜茧蜂等7种。天敌对麦蚜的自然控制效能,从天敌在田间发生期、数量比、捕食量进行评价。天敌对麦蚜混合种群数量的调节作用,经过“麦蚜数量转换期”和“天敌数量转换期”完成一个追随周期”追随周期在直角坐标平面上是一不规则圆形曲线。

There are 8 species from 64 varieties of natural enemies for wheat aphid in the winter wheat-protucing area in Holthern Henan and 7 cpecies from then such as Coccinella Setempunctata, Epictrophebalteata, Erigonidium graminicolum, Diaetiellarape, belong to dominant ones. Evaluation of the naturally controlling efficacy should be made on the basis of the field occurrence cycle of natural enemies,the ratio between their number and aphid and the number of insect caught by them. The controlling effect on the species-mixed aphid population has been produced through The'number change time of theat aphid',and'number change period of natural enemies',which forms a folloing cycle. The following cycle appears on the surface of right angle coodinate as an irregular curve.