黄玛草蛉对木瓜粉蚧的捕食作用评价

Functional response of Mallada basalis(Walker)(Neuroptera:Chrysopidae)on Paracoccus marginatus Williams and Granara de Willink(Hemiptera:Pseudococcidae)

为明确黄玛草蛉Mallada basalis(Walker)对木瓜粉蚧Paracoccus marginatus Williams and Granara de Willink的捕食作用,在实验室条件下观察了黄玛草蛉2龄、3龄幼虫对木瓜粉蚧2龄、3龄若虫及成虫的捕食选择偏好,同时采用捕食功能反应方法评价了黄玛草蛉2龄、3龄幼虫对木瓜粉蚧各虫态的捕食效能。结果表明,黄玛草蛉2龄、3龄幼虫偏好捕食木瓜粉蚧若虫,对木瓜粉蚧各虫态的捕食量均随着猎物密度的增加而增加符合HollingⅡ模型。其中,黄玛草蛉3龄幼虫具有较高的捕食能力,其对木瓜粉蚧2龄、3龄若虫及成虫的日最大捕食量分别为116头、81头和19头,a/Th值(a为瞬时攻击率,Th为处置单头猎物时间)分别为284.76、134.26和28.38。黄玛草蛉幼虫对猎物的寻找效应随猎物密度的增加而呈线性下降,且在相同猎物密度条件下,黄玛草蛉3龄幼虫对猎物的搜寻效应明显高于2龄幼虫。研究结果表明,黄玛草蛉对木瓜粉蚧具有较好的捕食能力。

The prey stage preference and functional response of Mallada basalis(Walker)(Neuroptera:Chrysopidae)to Paracoccus marginatus Williams and Granara de Willink(Hemiptera:Pseudococcidae)were tested under laboratory conditions.Overall,the 2 nd and 3 rd instar larvae of M.basalis preferred the nymphs of P.marginatus rather than the adults.The studies revealed that behaviour of both the 2 nd and 3 rd instar larvae of M.basalis matched Holling s Type II functional response.With increased density of P.marginatus,the number of preys consumed by the 3 rd instar larvae of M.basalis was higher than that by the 2 nd instar larvae.The daily maximum number of the second,third instar nymph and adults of P.marginatus consumed by the 3 rd instar larvae of M.basalis were 116,81 and 19,respectively,and the corresponding a/Th(a is the attack rate,Th is the handling time)value were 284.76,134.26 and 28.38,respectively.The searching rate of M.basalis larvae decreased with the increase of prey densities,and the 3 rd instar larvae of M.basalis showed a higher searching efficiency than that of the 2 nd instar larvae.Results showed that M.basalis was an efficient predator for biological control of P.marginatus.