The ant-plant mutualism mediated by extrafloral nectaries (EFNs) is based on the provision of extrafloral nectar (a sugar-rich liquid) in exchange for ant defense against herbivores. The extrafloral nectar production can vary depending on the intensity or types of leaf damage caused by different mouthparts of insect herbivores (i.e., sucking or chewing insects). However, it is poorly known how the type of herbivore damage changes the outcomes of tri-trophic interactions. Here, we address how the damage inflicted by different herbivore groups affects extrafloral nectar production and ants’ attendance and aggressiveness. Through an experimental field study, we tested whether the type of leaf damage, sucking or chewing, changes extrafloral nectar volume and sugar concentration, and subsequently ant composition and behavior. We evaluated the extrafloral nectar production and ant attendance and aggressiveness before and after simulated herbivory in Qualea parviflora (Vochysiaceae), a Brazilian savanna EFN-bearing plant. We found that only plants with sucking damage increased the sugar concentration of their extrafloral nectar, only plants with chewing damage increased ant abundance, and surrogate herbivore predation differed before and after simulated herbivory only for sucking damage. We provided the first evidence that the type of damage can influence ant aggressiveness via changes in extrafloral nectar production, translating to changes in the outcomes of this ant-plant mutualism. Ultimately, studies should consider the effects of herbivore damage type when studying insect-plant interactions.

由花外蜜（EFNs）介导的蚂蚁植物共生是基于提供花外蜜（富含糖的液体）来换取对草食动物的蚂蚁防御。花蜜的产生可能取决于昆虫食草动物（如吮吸或咀嚼昆虫）的不同口器引起的叶片损伤的强度或类型。然而，鲜为人知的是草食动物损害的类型如何改变三营养相互作用的结果。在这里，我们讨论了不同草食动物群体造成的损害如何影响花蜜的产生以及蚂蚁的出勤和侵略性。通过一项实验性田间研究，我们测试了叶片受损，吸吮或咀嚼的类型是否会改变花蜜的量和糖浓度，以及随后的蚂蚁成分和行为。Qualea parviflora（Vochysiaceae），巴西大草原EFN轴承植物。我们发现，只有遭受吮吸损害的植物才会增加其花蜜的糖浓度，只有遭受咀嚼损害的植物才会增加蚂蚁的丰度，而替代草食动物的捕食行为在模拟食草动物之前和之后的差异仅在于吮吸损害。我们提供了第一个证据，表明损害的类型可以通过花外花蜜产量的变化影响蚂蚁的侵略性，从而转化为这种蚂蚁植物互惠的结果的变化。最终，研究在研究昆虫与植物的相互作用时应考虑草食动物损害类型的影响。