Effects of ants on predator-prey interactions among mites in agro-ecosystems

蜘蛛生活在树叶表面和薄薄的丝网之间。蜘蛛通过呆在蜘蛛网内来躲避蚂蚁等多面手的捕食者，而蜘蛛则通过离开蜘蛛网来躲避侵入它们网的捕食性螨类。然而，在这两种捕食者的存在下，蜘蛛蠕虫相互冲突的反捕食者防御系统被打破；蜘蛛对捕食性蠕虫的反应是从网中移出的蠕虫被蚂蚁捕食。这项研究提供了第一个证据，表明蚂蚁可能对捕食性螨类对蜘蛛的生物控制起到了积极作用。此外，在上述研究过程中，我们还发现，针对捕食者的协作网络共享促进了蜘蛛的群居，而不建立保护网的蜘蛛物种对捕食者有另一种防御。

Spider mites live in the space between leaf surfaces and thin silk webs. Spider mites avoided generalist predators such as ants by staying inside the webs, while the mites avoided predatory mites that intruded into their webs by exiting the webs. In the presence of both predators, however, the conflicting antipredator defenses of spider mites broke down; the mites that moved out of the webs in response to predatory mites were preyed upon by ants. This study offers the first evidence that ants may have a positive effect on the biological control of spider mites by predatory mites. Moreover, we also found in the course of the above study that cooperative web sharing against predators promotes group living in spider mites and that spider mite species that does not build protective webs has an alternative defense against predators.