异色瓢虫幼虫对云南云杉长足大蚜若虫的捕食效应

在室内研究了捕食性天敌异色瓢虫4龄幼虫对云南云杉长足大蚜若虫的捕食作用。结果表明,异色瓢虫对云南云杉长足大蚜若虫的捕食功能反应符合HollingⅡ型反应,拟合的圆盘方程为N_a=1.028 9 N_t/(1+0.009 8 N_t)。根据HollingⅢ型功能反应新模型N_a=a·exp~(-b/N_t)计算出最佳寻找密度43.54头;在猎物密度一定的情况下,利用其捕食作用率与个体间相互干扰作用的关系用Hassell-Varley的干扰反应模型拟合为E=0.242 4P~(-0.398 5);分摊竞争强度与其密度的关系式为I=0.005 4lgP+0.679 6。利用Holling(1959)寻找效应(E)与猎物密度(N_t)关系式计算了寻找效应;利用HassellVarley(1969)模型和Beddington(1975)2种模型对异色瓢虫4龄幼虫寻找效应和自身密度之间的关系进行了模拟,模拟方程分别为:E=0.748 7P~(-1.298 4)、E=1.021 3/(2.479 4P-1.479 4)和E=1.021 3/(0.01 N_a+2.479 4P-1.479 4),异色瓢虫对云南云杉长足大蚜的寻找效应随猎物密度及捕食者密度的增加而下降。

Predatory efficiencies of the multicolored Asian lady beetle Harmonia axyridis larvae on the aphid Cinara alba nymphs

In the laboratory,the predation of the multicolored Asian lady beetle Harmonia axyridis larvae to the aphid Cinara alba nymphs was studied.The results showed that the functional response of H .axyridis larvae to C .alba nymphs fitted to Holling type Ⅱmodel and the equation was N a=1.028 9 N t/(1+0.009 8N t ).The best seeking density was about 43.54.The relationship between searching efficiency and H .axyridis larvae density was also studied by Holling’s model E =a/(1+at hN t ).The relationship between predation efficiency and individual interference could be fitted to the Hassell-Varley model E =0.242 4P -0.398 5 .The relationship between intensity of scrambling competition (I )and the density of the H .axyridis larvae (P )was I =0.005 4 lgP +0.679 6.The re-lationship between searching efficiency and H .axyridis larval density was also studied by Holling model.The rela-tionship between searching efficiency (E)and H .axyridis larval density (P )could be described by Hassell&Var-ley model and Beddington (1975)two models as E =0.748 7P -1.298 4 ,E =1.021 3/(2.479 4P -1.479 4)and E =1.021 3/(0.01N a+2.479 4P -1.479 4).The searching efficiency declined when the densities of H .axyridis lar-vae and the prey increased.