斯氏钝绥螨对西花蓟马和豆大蓟马若虫的捕食功能反应

The functional predatory response of Amblyseius swirskii to Frankliniella occidentalis and Megalurothrips usitatus nymphs

【目的】为明确斯氏钝绥螨Amblyseius swirskii对西花蓟马Frankliniella occidentalis和豆大蓟马Megalurothrips usitatus不同龄期若虫的捕食量及控制潜能。【方法】在25℃和75%相对湿度下,研究了斯氏钝绥螨雌成螨对两种蓟马1龄和2龄若虫的捕食喜好性、功能反应以及捕食螨自身的干扰反应。【结果】斯氏钝绥螨无论对西花蓟马还是豆大蓟马,在各自1龄和2龄若虫共存状况下,对1龄若虫的喜好性均显著高于2龄。捕食螨对两种蓟马1龄若虫的捕食量和喜好性无显著差异,但对西花蓟马2龄若虫的捕食量和喜好性显著大于豆大蓟马2龄若虫。斯氏钝绥螨雌成螨对西花蓟马和豆大蓟马的1龄若虫和2龄若虫的捕食功能反应均符合HollingⅡ型方程。捕食螨对西花蓟马和豆大蓟马1龄若虫的日均捕食量均随其自身密度的增加而逐渐降低。【结论】斯氏钝绥螨的捕食量与蓟马的种类和龄期有关,也与捕食螨的密度有关。

[Objectives] To investigate the potential of Amblyseius swirskii to act as a biological control for nymphs of the thrips Frankliniella occidentalis and Megalurothrips usitatus.[Methods]The prey preferences and functional and interference responses of A.swirskii to nymphs of F.occidentalis and M.usitatus were measured at 25℃ and 75%RH under laboratory conditions.[Results]A.swirskii preferred 1 st instar nymphs of both F.occidentalis or M.usitatus to 2 nd instar nymphs of these species,and there was no difference in its predatory capacity,or preference,for 1 st instar nymphs of either species.However,A.swirskii preferred 2 nd instar nymphs of F.occidentalis to those of M.usitatus.The functional response was a good fit to the HollingⅡequation.The predation rate of A.swirskii on 1 st instar nymphs decreased with predator density.[Conclusion]The predatory capacity of A.swirskii was affected by the species and developmental stage of its prey and predator density.