异色瓢虫耐饥能力及饥饿对其捕食槐蚜功能的影响

试验结果表明,异色瓢虫4龄幼虫和成虫在饥饿条件下寿命最长。不同饥饿程度的异色瓢虫3～4龄幼虫、成虫的捕食量均随槐蚜密度的增加而增加,对槐蚜捕食的功能反应均属于HollingⅡ型,经χ ²检验,各圆盘方程理论值和实测值拟合较好。同一虫态不同饥饿程度的异色瓢虫对槐蚜的捕食情况无明显差异。饥饿48 h的异色瓢虫3～4龄幼虫、成虫在24 h内对槐蚜的捕食作用主要集中在初始阶段,即本试验的0～6 h内。

Starvation tolerance of Harmonia axyridis and influence of starvation on its predation on Aphis sophoricola

The results indicated that there were great difference between the longevity of the larvae and adults of Harmonia axyridis Pallas under starvation conditions. The longevity of the 4th instar larva and the adult was longer than the others. The larvae and adults of H. axyridis tinder different starvation conditions predated more with the increase of prey density, hut no obvious difference in the number of the same instars or adults predated at the same prey density has been observed. Functional response of H. axyridis to Aphis sophorlcola fitted Holling--II type equation. X^2 test showed that the theoretical expectation calculated by Holling disc equation was fitted well with the observed values. The predation by the larvae and adults starved for 48 hours was concentrated in the first 6 hours of the 24 hours experimental period.