异色瓢虫成虫对槐豆木虱的捕食作用

在室内测定异色瓢虫［Harmonia axyridis (Pallas)］成虫对槐豆木虱［Cyamophila willieti（Wu）］若虫的捕食作用。结果表明，异色瓢虫对槐豆木虱若虫的捕食功能反应符合HollingⅡ（1959）型方程，拟合的圆盘方程为Na＝1.128 47Nt/（1+0.010 1Nt），经χ2适合性测验表明，圆盘方程的预测值与实测值相符；对猎物的捕食选择效应表明，在槐豆木虱和槐蚜(Aphis robiniae Macchiati)之间，异色瓢虫更喜好槐豆木虱；异色瓢虫的捕食率与个体间的相互干扰关系，用Hassell（1969）等的模型拟合为E＝0.577 668P-0.275；对自身密度的功能反应，用Watt(1959)模型拟合为A＝98.73P-0.705 3；在此基础上，根据HollingⅢ型功能反应新模型Na=a•exp (-bN-1t)拟合，求得日均最大捕食量102.3头，最佳寻找密度61.1头。

Predation of Cyamophila willieti by the adults of Harmonia axyridis

Predation by Harmonia axyridis adults on Cyamophila willieti nymphs was investigated in the laboratory. Functional response of adult H. axyridis to the nymph of C. willieti could be fitted by HollingⅡ（1959）model, Na＝1.128 47Nt/（1+0.010 1Nt）. χ2 test showed that the theoretical value calculated by the fitted Holling disc equation conformed well with the observed values. When provided with C. willieti and Aphis robiniae at the same time, adult H. axyridis preferred C. willieti. The individual interference with predation efficiency could be fitted with Hassell（1969）model, E＝0.577 668P-0.275. The functional response of adult H. axyridis to its own density could be fitted with the Watt (1959) model, A＝98.73P-0.705 3. On the basis of these results and HollingⅢ functional response model Na=a•exp(-bN-1t), the largest average daily volume was calculated to be 102.3 preys, and the optimum searching density was about 61.1 per adult.