异色瓢虫对莲缢管蚜的捕食作用研究

Predation of Harmonias axyridis Pallas on Rhopalosiphum nymphaeae Linne (Homoptera:Aphididae)

异色瓢虫对莲缢管蚜的捕食功能反应符合HollingII型方程,其捕食量随猎物密度的增加而增大,寻找效应随着猎物密度的增加而降低。与此同时,研究结果还表明,异色瓢虫的捕食作用有较强的种内干扰反应,随着捕食者密度的增大,平均捕食量逐渐减少,捕食作用率也相应降低,其干扰反应模型为:E=0.36P-1.3112(3龄幼虫)、E=0.522 4P-1.909 6(4龄幼虫)和E=0.384 5P-1.856 3(成虫)。

The functional response of Harmonias axyridis Pallas predating on Rhopalosiphum nymphaeae Linne old nymphs fitted the model of Holling 11 type well. The higher of prey density was,the larger of predation number and the lower finding efficiency were observed. The models of functional response of the Harmonias axyridis Pallas to the Rhopalosiphum nymphaeae Linne were respectively N =0. 682 268N/1 ＋0. 008 185 N （2nd instar larvae）, N = 0. 850 774N/1 ＋ 0. 007 414N（3rd instar larvae）, N = 0. 985 902N/1 ＋ 0. 008 908N（4th instar larvae）and N = 0. 796 622N/1 ＋ 0. 006 778N（adult）. At the same time, intraspecific interference was found in the experiment, the average predation number and predation rate of Harmonias axyridis Pallas decreased with the increasing of its density, the relationship between predation ratio（E） and natural enemy density （P） was described with the equations of E = 0. 36 p^-1.3121 （3rd instar larvae）, E = 0. 522 4P^-1.909 6 （4th instar larvae） and E =0. 384 5P^- 1.8563 （adult）.