中华草蛉、龟纹瓢虫和异色瓢虫对B型烟粉虱的捕食功能反应

室内研究了中华草蛉Chrysopa sinicaTjeder、龟纹瓢虫Propylaea japonica(Thunberg)和异色瓢虫Leis axyridis(Pallas)对B型烟粉虱Bemisiatabaci(Gennadius)若虫的捕食功能反应和寻找效应。结果表明,3种天敌成虫和幼虫的捕食量均随着猎物密度的增加而上升,当猎物增加到一定水平,捕食量趋向稳定,捕食功能反应曲线符合HollingⅡ型方程。异色瓢虫、中华草蛉和龟纹瓢虫成虫和幼虫对烟粉虱若虫的捕食量差异显著,理论最大日捕食量分别为417,263,156头和625,238,108头。3种天敌对烟粉虱若虫的寻找效应随着天敌密度的增加而下降,干扰作用逐渐增强,其寻找效应表现为龟纹瓢虫(0.5656)>异色瓢虫(0.4371)>中华草蛉(0.4029),对烟粉虱的控制能力表现为异色瓢虫>龟纹瓢虫>中华草蛉。

Functional responses of Chrysopa sinica, Propylaea japonica and Leis axyridis to Bemisia tabaci

The predatory capacity and searching efficiency of Chrysopa sinica Tjeder,Propylaea japonica(Thunberg) and Leis axyridis(Pallas) to Bemisia tabaci(Gennadius) B biotype were explored in the laboratory.It was found there was a negative relationship between amount of B.tabaci nymph preyed by C.sinica,P. japonic,L.axyridis and nymphal density.The predatory functional response of C. sinica,P.japonica and L.axyridis female adults,male adults and larvae fitted better to Holling's EquationⅡ.The parameter analysis from the equations indicated that there were significant differences in predatory amounts among the three species.The maximum predatory amounts daily for L.axyridis,C.sinica and P.japonica to B.tabaci were 417,263,156 and 625,238,108 individuals,respectively.The searching efficiency decreased with increase of predator density,and the order of the searching efficiency was P.japonica(0.5656)> L.axyridis(0.4371)> C.sinica(0.4029), while the control effects to B.tabaci was listed as L.axyridis> P.japonica> C.sinica.