Identification of a novel plant-derived attractant for Acromyrmex lobicornis leaf-cutting ants

Abstract: Leaf-cutting ants are considered major pests of agriculture and forestry in the Neotropics. Attractive toxic baits are the prevailing method for managing them. Thus, there is great interest in identifying attractants to incorporate into these baits. Moreover, leaf-cutting ants can avoid toxic baits by associating the attractant with the toxin. We evaluated attractiveness of heptyl butyrate, a volatile compound found in fresh apples and plums. We conducted field experiments with ten colonies ofAcromyrmex lobicornis. First, we evaluated the behaviour of ants exposed to heptyl butyrate at 1% by surrounding resources. Then, we compared the attractiveness of heptyl butyrate and orange pulp, the most commonly used attractant. Finally, we evaluated whether heptyl butyrate increases the attractiveness of a carbohydrate resource at varying doses. Heptyl butyrate at 1% attracted 92% more ants than the control and that it was as attractive as orange pulp. Heptyl butyrate paired with sucrose at concentrations of 0.001 and 0.1% was more attractive than sucrose alone, but greater concentrations did not increase sucrose’s attractiveness. Therefore, heptyl butyrate could be added to toxic baits to manageA. lobicornisas it is as attractive as the most commonly used attractant and can be applied directly to the pellets.摘要：切叶蚁被视为新热带区农林生产中的主要害虫。具有引诱活性的毒饵是当前防治该类害虫的主流手段，因此人们对可添加至此类毒饵中的引诱剂的研发具有浓厚兴趣。此外，切叶蚁可通过将引诱剂与毒素建立关联而规避毒饵。本研究针对新鲜苹果与李子中检出的挥发性化合物丁酸庚酯（heptyl butyrate）的引诱效果展开评估，以10个粗糙切叶蚁（Acromyrmex lobicornis）蚁群为研究对象开展野外试验。首先，通过在食物源周边施加1%浓度的丁酸庚酯，我们评估了切叶蚁暴露于该物质后的行为响应；随后，对比了丁酸庚酯与当前最常用引诱剂橙肉的引诱活性；最后，探究了不同剂量的丁酸庚酯是否可提升碳水化合物食物源的引诱效果。试验结果表明：1%浓度的丁酸庚酯相较对照组可多吸引92%的蚂蚁，且其引诱效果与橙肉相当；当丁酸庚酯与0.001%、0.1%浓度的蔗糖复配时，其引诱效果优于单一蔗糖溶液，但更高浓度的丁酸庚酯并未进一步提升蔗糖的引诱性。综上，丁酸庚酯可添加至毒饵中用于防治粗糙切叶蚁：其引诱效果与当前主流引诱剂相当，且可直接添加至毒饵颗粒中。