Ant–hemipteran mutualisms can have positive and negative effects on host plants depending on the level of hemipteran infestation and plant protection conferred by ants against folivory. Differential effects of such mutualisms on plant survival are well documented in undisturbed and ant‐invaded systems, but few have explored how anthropogenic disturbance affects interactions between hemipterans and native ant species and what the consequences may be for recovering ecosystems. Within a fragmented landscape in Costa Rica, restored tropical forests harbor a mutualism between the native ant Wasmannia auropunctata and the scale insect Alecanochiton marquesi on the abundant, early‐successional tree Conostegia xalapensis. I added A. marquesi scales to C. xalapensis seedlings and either allowed or excluded W. auropunctata to investigate if this mutualism leads to increased scale infestation, decreased scale mortality, and decreased folivory. I also examined whether these effects are mediated by the percentage of remnant forest cover in the landscape. I found that seedlings with ants excluded had fewer scale insects and higher herbivory than plants with ants present. I also found evidence that scale mortality due to fungal attack and parasitism was higher on ant‐excluded versus ant‐allowed seedlings but only at sites with high surrounding landscape forest cover. Together, these results suggest that mutualisms between scale insects and native ants can promote scale infestation, reduce folivory on native plant species, and potentially disrupt biological control of scale insects in recovering tropical forests. Further, my experiment underscores the importance of remnant tropical forests as sources of biological control in anthropogenically disturbed landscapes.

中文翻译：

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蚂蚁规模的共生增加了规模的侵扰，减少了叶子，并破坏了恢复的热带森林的生物控制

蚂蚁与半翅目的共生关系对寄主植物有正面或负面的影响，具体取决于半翅目对昆虫的侵染程度和蚂蚁对叶片的植物保护作用。在不受干扰和被蚂蚁入侵的系统中，这种共生关系对植物存活的不同影响已得到充分证明，但很少有人探讨人为干扰如何影响半足动物与本地蚂蚁物种之间的相互作用，以及对恢复生态系统的后果。在哥斯达黎加的一个零散的景观中，恢复的热带森林在原生的蚂蚁Wasmannia auropunctata和鳞翅目昆虫Alecanochiton marquesi之间存在着共生关系，而后者在丰富的，早期成功的Conostegia xalapensis树上。我加了马克斯可以缩放到C. xalapensis苗，并允许或排除W. auropunctata进行调查，以确定这种共生关系是否导致鳞片侵害增加，鳞片死亡率降低和叶肉减少。我还检查了这些影响是否由景观中剩余森林覆盖的百分比所介导。我发现，排除蚂蚁的幼苗比带有蚂蚁的植物的昆虫少，食草性更高。我还发现有证据表明，在蚂蚁排斥的幼苗上，由于真菌侵袭和寄生而导致的规模死亡率要比在蚂蚁允许的幼苗高，但仅在周围森林覆盖率高的地方。总之，这些结果表明，介壳虫和原生蚂蚁之间的相互关系可以促进介壳虫侵染，减少原生植物种类的叶肉，并有可能破坏恢复热带森林中介壳虫的生物控制。此外，我的实验强调了残留的热带森林作为人为干扰景观中生物控制来源的重要性。