异色瓢虫对白毛蚜捕食作用的研究

PREDATION OF LEIS AXYRIDIS ON CHAITOPHQRUS PCPULIALBAE

试验研究了异色瓢虫Leis axyridis(Pallas)各龄幼虫和成虫对白毛蚜Chaitophorus populialbae无翅成蚜的捕食功能反应及其成虫的寻找效应。功能反应均属Holling Ⅱ型。异色瓢虫成虫寻找效应和自身密度之间的关系用Hassell & Varley (1969)模型E=QP^(-m)和Beddington(1975)模型E=aT/[1+bt_w(P-1)]进行了模拟,Beddington模型更好地反映寻找效应和瓢虫密度之间的关系。寻找效应与瓢虫成虫自身密度和蚜虫密度之间的关系用Reddington(1975)模型E=aT/[1+at_hN+bt_w(P-1)]进行描述,表明寻找效应(E)随瓢虫密度(P)和猎物蚜虫密度(N)的增大而下降。

Laboratory studies show that the functional responses of 1-4 instar larvae and adult of Lets axyrtdis to wingless adult aphids Chaitophorus populialbae belong to Holling II type. The relationship between searching efficiency (E) and the adult la-dybird density (P) is described by HasseJJ & Varley's model E= QP^(-m) and Bed-dington's model E = aT/[ 1 + btw (P- 1)] as E=0.4286P-0.6555 and E = 0.4108/ (0.6288 + 0.3712P), respectively. Both models demonstrate that the searching effi-ciency declines with increase of the ladybird density, but Beddington's model can describe the relationship better than Hassell & Varley's model. The relationship be-tween searching efficiency (E) and the prey density (N) and the adult ladybird density(P) is described by Beddington's model E = aT/[1 + athN + btw(P-1)] as E = 0.4108/(0.6288 + 0.002846N + 0.3712P), i.e. the searching efficiency declines, when the adult ladybird and the prey densities increase.