【摘要】 大豆蚜Aphis glycinesMatsmura种群增长随时间而变化,符合Logistic增长模型,得出回归方程N=58.5330/(1+e4.8704-0.2274t),当t≈21时,可作为防治大豆蚜的关键时期,此时正值田间大豆苗期的营养生长盛期。大豆苗期随着蚜量上升,危害损失增加。根据田间蚜虫密度与危害损失率之间的相互关系,大豆蚜的防治指标可确定为平均每穴蚜量24头或800头/百株。更多还原

【Abstract】 The occurrence and control threshold of Aphis glycines Matsmura in fresh soybean field were studied through methods of field systematic investigation.The results showed that the population growth of A.glycines accorded with Logistic model,and the relationship between the quantity of A.glycines（N） and the days after emerging of soybean plants（t） was established as N=58.5330/(1+e^{4.8704-0.2274t}).The critical period to control A.glycines should be about 21 days after emerging of soybean plants,when is also the growth period of soybean plants to accumulate nutrients.The model of relationship between percentages of yield loss（Y） and the quantity of A.glycines（X） was established as Y=-2.5141+2.2293X.The control threshold was about 24 individuals per aperture or 800 individuals per 100 plants.更多还原