Predatory functional response of Harmonias axyridis on Megoura japonica

To clarify the predation abilities and predatory functional response of different stage of Harmonias axyridis on Megoura japonica, an experiment was conducted in an intelligent light indoor incubator operating at a temperature of (24±1) ℃, relative humidity of (70%±10%), and light∶dark cycles of 14 h∶10 h. There were significant differences between different stages of H. axyridis with respect to their daily predatory capacity on M. japonica. The predation of H. axyridis female adult and fourth instar larvae were stronger than others and their daily maximum prey capacity were 217.39 and 196.08 head·d-1, respecitiverly). They also had a lower duration of possible predation on aphids, which were 0.004 6 and 0.005 1 d, respectively. The functional responses of different stages of H. axyridis to different density of M. japonica fitted well with the Holling Ⅱ model. The searching efficiency of different stages H. axyridis decreased with increasing density of M. japonica.