异色瓢虫对豆蚜的捕食功能反应

The predation functional response of Harmonia axyridis Pallas to Aphis craccivora

试验开展了异色瓢虫Harmonia axyridis Pallas对豆蚜Aphis craccivora Koch的捕食功能反应研究。结果表明,异色瓢虫各虫态的功能反应类型均属于HollingⅡ型。随着豆蚜数量的上升,异色瓢虫对豆蚜的捕食增加量逐渐减小直至趋于稳定。异色瓢虫各龄幼虫、成虫对豆蚜的寻找效应均随豆蚜数量的增加而减小。异色瓢虫4龄幼虫的a/Th值最大,为2255.67,捕食功能最强,其后为成虫、3龄、2龄、1龄幼虫。

The test on predation functional response about Harmonia axyridis to bean aphid was studied. The results indicated that predation effects of H. axyridis each larvae to Aphis craccivora were corresponding with Holling Ⅱ model pattern. With the increase of prey density, the increasing amount of H. axyridis preying bean aphid decreased gradually and was going to be a steady value. Larvae and adults of H. axyridis had the lower searching efficiency with the increase of prey density. The maximum value of a/Th belongs to the fouth instar with 2255.67, which means the fourth instar is the strongest predator, followed it up with adult, the third instar, the second instar, the first instar larvae successively.