背景:几种植物性物种可以潜在地控制柑橘锈螨(CRM)。它们的有效性各不相同,然而,他们内部的互动也是如此。在实验室条件下,规定的Euseius,E.黄体和伊菲修士在CRM上有效地捕食,而旋流成虫和无花虫对CRM没有影响。结合A.swirskii,Euseius的数量由于内部捕食而减少,因此,CRM抑制效果较差。在田野里,掠食性螨物种可以通过从诸如罗得岛草(RG)等覆盖作物释放的风传花粉来可变地提供。我们的目的是在两个现场实验中确定RG对植物群落的影响,在不同品种(柚子和Shamouti橙)上。我们还测试了这些群落的种间丰度负关系,如果它们各自的实验室观察到的内部相互作用在野外表现出来,这是预期的。
结果:总体而言,在柚子上,我们观察到了旋流A的优势,相对较低的大肠杆菌和较高的CRM丰度。Amblyseiusswirskii和E.spiniatus丰度都在RG附近升高,尽管A.swrskii明显的内部捕食。相反,硫铁矿丰度在RG附近较低,可能是由于A.swirskii的捕食。在Shamouti上,紫菜的丰度远高于柚子,与漩涡草的丰度没有负相关。在那里,RG增加了紫菜的丰度,CRM减少了。
结论:RG覆盖种植可以增强CRM控制,取决于植物之间的内部相互作用的变化,特别是在A.旋流和E.规定之间。这些可以通过气候和/或品种效应来调节。©2018化学工业学会。
BACKGROUND: Several phytoseiid species can potentially control the citrus rust mite (CRM). Their effectiveness varies, however, as do their intraguild interactions. Under laboratory conditions, Euseius stipulatus, E. scutalis and Iphiseius degenerans preyed effectively on CRM, whereas Amblyseius swirskii and Typhlodromus athiasae had no effect on CRM. In combination with A. swirskii, Euseius numbers were reduced due to intraguild predation, and consequently CRM suppression was less effective. In the field, predatory mite species can be variably provisioned by windborne pollen released from cover crops such as Rhodes grass (RG). We aimed to determine the effects of RG on the phytoseiid community in two field experiments, on different cultivars (pomelo and Shamouti orange). We also tested these communities for negative interspecific abundance relationships that are expected if their respective laboratory-observed intraguild interactions are manifested in the field.
RESULTS: Overall, on pomelo, we observed a dominance of A. swirskii, relatively low E. stipulatus and high CRM abundances. Amblyseius swirskii and E. stipulatus abundances were both elevated near RG, despite apparent intraguild predation by A. swirskii. Conversely, T. athiasae abundances were lower near RG, likely due to predation by A. swirskii. On Shamouti, E. stipulatus abundances were much higher than on pomelo and were not negatively related to A. swirskii abundances. There, RG increased E. stipulatus abundance, and CRM was reduced.
CONCLUSIONS: RG cover cropping can enhance CRM control, depending on variation in intraguild interactions among phytoseiids, particularly between A. swirskii and E. stipulatus. These may be modulated by climatic and/or cultivar effects. © 2018 Society of Chemical Industry.