论文部分内容阅读
八十年代以来,我区麦蚜频繁成灾,减产2—3成的麦田较为普遍,研究证明:成灾的主要原因是优势种群已由麦长管蚜Sitobion avenae(Fabr.)转变为禾谷缢管蚜Rhopalosiphumpadi(L.)。田间调查弄清了禾谷缢管蚜在不同海拔高度的早、中、晚播麦田的不同生育阶段,以及在植株各部位的分布。穗期禾谷缢管蚜发生轻重与3月中旬平均温度呈正相关,与3月下旬雨量呈负相关。由此建立了预测禾谷缢管蚜发生程度的多元回归方程式: Y=0.792+0.205X_1-0.015X_2用这个预测式回测8年田间实测值与预测值极近。
Since the 1980s, the wheat aphids in our district have been frequently disastrous and the yield reduction of 2-3% of the wheat fields has become more common. Studies have shown that the main cause of the disaster is that the dominant populations have been transformed from Sitobion avenae (Fabr.) Into cereals Rhopalosiphumpadi (L.). Field surveys identified the different stages of development of the wheat aphids in the early, middle and late sowing wheat fields at different altitudes and in all parts of the plant. The occurrence and the severity of Aphis gossypii at the heading stage were positively correlated with the average temperature in mid-March and negatively correlated with the rainfall in late March. The multivariate regression equation was established to predict the degree of occurrence of Aphis gossypii: Y = 0.792 + 0.205X_1-0.015X_2. With this prediction, the 8-year field measurements were in good agreement with the predicted values.