杭州悬铃木方翅网蝽的捕食性天敌种类及日本通草蛉幼虫捕食作用

Predators of Corythucha ciliata (Say) in Hangzhou and the Predation of Chrysoperla nipponensis (Okamoto) Larvae

本文调查发现杭州悬铃木方翅网蝽Corythuchaciliata(Say)的捕食性天敌有5科7种,主要是日本通草蛉Chrysoperla nipponensis(Okamoto)、普通草蛉Chrysoperla carnea(Stephens)和小花蝽属Oriusspp.。日本通草蛉幼虫对悬铃木方翅网蝽成虫、若虫的捕食功能反应均符合HollingII型方程,捕食作用强弱为:日本通草蛉3龄幼虫捕食若虫>日本通草蛉2龄幼虫捕食若虫>日本通草蛉3龄幼虫捕食成虫,其对应的搜寻效率α与处理时间Th值分别为1.0141、0.5687、0.3757和0.0075、0.0121、0.0267。成虫和若虫共存时,日本通草蛉3龄幼虫喜好捕食若虫。日本通草蛉幼虫的搜寻效应随猎物密度的增加而降低。在悬铃木方翅网蝽若虫密度相同的条件下,日本通草蛉2龄、3龄幼虫随着自身密度的增大,其平均捕食量逐渐减少,捕食作用率也相应降低,其捕食作用率E与自身密度P的关系分别为:E=0.3164P-0.4700和E=0.3411P-0.4762。日本通草蛉幼虫间存在分摊竞争。

Seven species of predators of Corythucha ciliata（Say）,which belongs to 5 families,were found in Hangzhou,in which Chrysoperla nipponensis（Okamoto）, Chrysoperla carnea（Stephens） and Orius spp.were the most numerous and widely distributed species.The functional responses of C.nipponensis larvae on C.ciliata could be described with the Holling II equation,and the preying capacity of C. nipponensis larvae on C.ciliata nymphs or adults ranked as： the 3rd instar larvae of C.nipponensis on C.ciliata nymphs the 2nd instar larvae of C.nipponensis on C.ciliata nymphs the 3rd instar larvae of C.nipponensis on C.ciliata adults.Their corresponding attack rates（α） and handling times（Th） were 1.0141,0.5687,0.3757 and 0.0075,0.0121,0.0267,respectively.The 3rd instar larvae of C.nipponensis preferred nymphs over adults of C.ciliata.The searching rate of C.nipponensis larvae decreased with the increase of the prey density.At the same density of C.ciliata nymphs,the average predation capacity and predation rate of the 2nd and 3rd larvae of C.nipponensis decreased with the increase of its density.The relationship between predation ratio（E） and density （P） of the 2nd and 3rd larvae of C.nipponensis was E=0.3164 P-0.4700 and E=0.3411 P-0.4762,respectively.There was a scrambling competition among C.nipponensis larvae.