Leafcutter ants are a major pest in vineyards in Argentina, but their damage to vine plants has not been sufficiently quantified. Biological control against leafcutter ants has not been successful so far. Sugary rewards can trigger ants to act as plant bodyguards against a wide range of herbivores. The Argentine ant Linepithema humile (Mayr) is a common invader of vineyards worldwide and has a strong preference for carbohydrates. In a first 10-week field experiment, we attracted L. humile ants to a group of plants using sugar feeders, while no feeders were used for a second group. Ant-excluded control plants were also deployed. We quantified the damage inflicted by the leafcutter ant Amoimyrmex bruchi (Forel) on potted vines with and without L. humile ants. In a second short field experiment, we evaluated the impact of L. humile on A. bruchi foraging through the quantification of foraging activity and the amount of transported material as a function of L. humile presence. We found that A. bruchi caused >90% leaf area reductions in plants without L. humile, while plants where the species was present were rarely attacked and leaves developed similar to those of ant-excluded controls. Active interaction with L. humile decreased A. bruchi’s foraging activity and the amount of material transported by it. This is the first report of A. bruchi as a vineyard pest and the first quantification of the damage inflicted by a leafcutter ant on organic grapevines. We demonstrate that L. humile defends vine plants against herbivore pests and artificial sugar sources boost can this defense service. The development of biological control strategies that include the ecological services of ants as natural enemies of herbivorous pests could become a useful tool in sustainable viticulture and horticulture.

切叶蚁是阿根廷葡萄园的主要害虫，但它们对藤本植物的损害尚未得到充分量化。迄今为止，对切叶蚁的生物防治尚未成功。含糖的奖励可以触发蚂蚁充当植物保镖来对抗各种食草动物。阿根廷蚂蚁Linepithema humile (Mayr) 是全世界葡萄园的常见入侵者，对碳水化合物有强烈的偏好。在第一个为期 10 周的田间实验中，我们使用食糖器将L. humile蚂蚁吸引到一组植物中，而第二组没有使用食器。还部署了排除蚂蚁的对照植物。我们量化了切叶蚁Amoimyrmex bruchi (Forel) 对有和没有的盆栽藤蔓造成的损害L. 谦逊的蚂蚁。在第二个短场实验中，我们通过量化觅食活动和运输材料的数量作为L. humile存在的函数来评估L. humile对A. bruchi觅食的影响。我们发现A. bruchi在没有L. humile的植物中导致 > 90% 的叶面积减少，而存在该物种的植物很少受到攻击，并且叶子的发育与排除蚂蚁的对照相似。与L. humile的积极互动降低了A. bruchi的觅食活动及其运输的物质量。这是A. bruchi的第一份报告作为一种葡萄园害虫，首次量化了切叶蚁对有机葡萄藤造成的损害。我们证明了L. humile可以保护藤本植物免受食草动物害虫的侵害，而人造糖源可以增强这种防御服务。发展生物控制策略，包括蚂蚁作为食草害虫天敌的生态服务，可能成为可持续葡萄栽培和园艺的有用工具。