一、地上害虫田间为害症状识别及防治技术1、蚜虫。小麦蚜虫多集中在麦叶背面、叶鞘及新叶处;小麦拔节、抽穗后,多集中在茎、叶和穗部刺吸为害,并排泄蜜露(粪便),影响植物的呼吸和光合作用。被害处呈浅黄色斑点,严重时叶片发黄,甚至整株枯死。穗期为害,造成小麦灌浆不足,籽粒干瘪,千粒重下降,造成减产。另外,麦蚜还是传播病毒病的重要昆虫媒介,如小麦丛 First, the field pest damage symptoms identification and prevention and control technology 1, aphids. Wheat aphids mostly concentrated in the back of wheat leaves, leaf sheaths and new leaves; wheat jointing, heading, the more concentrated in stems, leaves and spike sucking damage, and excrete honey dew (feces), affecting plant respiration and photosynthesis. Victims were pale yellow spots, yellow leaves when severe, and even the whole plant died. Spike damage, resulting in insufficient wheat filling, dry grain, grain weight decreased, resulting in reduced production. In addition, the wheat aphid is also an important insect vector for the transmission of viral diseases, such as wheat clumps