瓢虫对烟蚜的控制效能及异色瓢虫与烟蚜茧蜂的取食竞争作用

为了明确4种主要捕食性瓢虫对烟蚜的控制效能及其与优势寄生性天敌烟蚜茧蜂的取食竞争作用,在室内条件下测定了七星瓢虫、异色瓢虫、六斑月瓢虫和龟纹瓢虫对烟蚜的捕食效能和异色瓢虫与烟蚜茧蜂的取食竞争作用。结果表明,4种瓢虫捕食烟蚜后均能正常完成发育,发育历期分别为异色瓢虫(17.11 d)七星瓢虫(16.25 d)六斑月瓢虫(13.69 d)龟纹瓢虫(12.73 d),其中异色瓢虫的4龄幼虫期最长,达4.15 d,显著高于其他瓢虫;异色瓢虫、七星瓢虫、六斑月瓢虫和龟纹瓢虫完成生长发育对烟蚜的总捕食量分别为687.0、635.6、359.2和253.2头,各瓢虫间差异显著。在烟蚜茧蜂和异色瓢虫的共存系统中,增加异色瓢虫的数量,异色瓢虫和烟蚜茧蜂对烟蚜的个体控制数量均会降低;增加烟蚜茧蜂的数量,显著降低了种内的个体寄生量,但对异色瓢虫的控蚜作用无明显影响。该研究结果将为合理利用天敌昆虫组合控制烟蚜提供技术依据。

The Predation Efficiency of Lady Beetles on Myzus persicae and Feeding Competition of Harmonia axyridis with Aphidius gifuensis

Predation efficiency of lady beetles on Myzus persicae Sulzer was tested with four lady beetle species,Coccinella septempunctata Linnaeus,Harmonia axyridis Pallas,Menochilus sexmaculata Fabricius and Propylea japonica Thunberg on M.persicae.Moreover,the feeding competition of two types of predators,H.axyridis and A.gifuensis were tested in laboratory.The four species of lady beetles could complete their whole development on M.persicae,developmental duration was ranked as H.axyridis (17.11 d),C.septempunctata (16.25 d),M.sexmaculata (13.69 d) and P.japonica (12.73 d).The duration of the fourth instars ofH.axyridis (4.15 d) was significantly longer than that of other species.The total predation on M.persicae varied significantly between the beetles,which was 687.0,635.6,359.2 and 253.2 forH.axyridis,C.septempunctata,M.sexmaculata and P.japonica,respectively.In coexistence of A.gifuensis and H.axyridis,the number of M.persicae attacked by A.gifuensis and H.axyridis decreased with increase in the number of H.axyridis.Parasitism by A.gifuensis decreased with increase of the number ofA.gifuensis,but predation by H.axyridis was not affected.The results will provide a theoretical base for rational utilization of two natural enemies for the control ofM.persicae.