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

蜘蛛螨生活在树叶表面和薄蜘蛛网之间的空间里。蜘蛛螨躲在网里躲避蚂蚁等多面手的捕食者，而螨虫则从网里出来躲避侵入其网的掠食性螨虫。然而，在这两种捕食者都存在的情况下，蜘蛛螨相互矛盾的反捕食者防御机制崩溃了；那些为了回应掠食性螨虫而离开蜘蛛网的螨虫被蚂蚁捕食。本研究首次证明蚂蚁对捕食性螨对蜘蛛螨的生物防治可能有积极作用。此外，在上述研究过程中，我们还发现，在捕食者面前，合作共享网促进了蜘蛛螨的群体生活，而不构建保护性网的蜘蛛螨则有另一种防御捕食者的方式。

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.