论文部分内容阅读
麦蚜(麦二叉蚜、麦长管蚜等)是榆中县小麦的主要害虫之一,在小麦整个生长期都会不同程度地造成危害。为了了解麦蚜天敌的控害能力及在综合防治中的利用价值,我们自1981年开始对麦蚜天敌的田间发生与消长进行了较系统的调查与试验研究。现将结果初报如下。一、调查方法 (一)定点观察:每年从四月上旬冬小麦返青、春小麦出苗后开始,到七月中旬小麦乳熟期为止,在三角城乡丁官营村选择经常不施药的小麦田作为观测现场。每次调查两块地,采用五点取样,每点1平方米,隔五天观测一次,计算各种天敌总头数,优势种群,益害比
Wheat aphids (wheat aphid, wheat aphid, etc.) is one of the major pests of wheat in Yuzhong County, which will be harmed to varying degrees throughout the growing season of wheat. In order to understand the control ability of the natural enemies of wheat aphids and their value in the integrated control, we conducted a systematic investigation and experimental study on the occurrence and growth of wheat aphid natural enemies in the field since 1981. Now the results reported below. First, the survey method (A) sentinel observation: every year from April early winter wheat rejuvenation, spring wheat emergence after the start of wheat milk ripening in mid-July so far, Dingcunying Triangle Township choose often do not apply wheat field as observation on site. Each survey two, using five sampling, each 1 square meter, observed once every five days, calculate the total number of all kinds of natural enemies, the dominant population, benefit ratio