Cocoa cultivation in so-called agroforestry systems is widespread in the Peruvian Amazon rainforest. There, cocoa plants grow alongside other trees in the same area. The problem is that leaf-cutter ants also like to build their nests there. Cocoa farmers often consider these insects pests because they cut off leaves, flowers and fruits, thereby reducing crop yields. Farmers, therefore, frequently use pesticides to control leaf-cutter ants.
A research team at Julius Maximilian University of Würzburg (JMU) has now investigated the impact of leaf-cutter ants on cocoa cultivation in agroforests and how best to respond to it. The key finding: ants are not necessarily harmful; they can also provide additional benefits to the cacao agroforest. What's more, the damage they cause can be reduced using simple methods that also have a positive effect on biodiversity.
Blanca Iváñez Ballesteros, postdoctoral researcher at the D epartment of Animal Ecology and Tropical Biology - Zoology III at JMU, was responsible for this study. The results are part of her dissertation in the DFG-funded project EcoCacao led by Prof. Ingolf Steffan-Dewenter with colleagues from Göttingen, Vienna and Lima, and have been published in the latest issue of the Journal of Applied Ecology.
‘Leaf-cutter ants are not just pests. As “ecosystem engineers”, they significantly alter the soil structure and nutrient dynamics of their environment. For sustainable agriculture, it is therefore crucial to understand the trade-offs between the damage caused by leaf-cutter ants and the ecological services they provide,’ says the scientist, describing the background to her work.
The key findings of the study can be summarised in five points:
Overall, the study advocates biodiversity-friendly farming that utilises both local tree diversity and the preservation of adjacent forests to create productive and resilient cropping systems. And for agriculture, the conclusion is clear: instead of combating ant nests with poison, farmers should focus on a clever mix of trees. By planting trees such as papaya as a ‘distraction’ and protecting the surrounding forest, they can produce good cocoa while preserving biodiversity.
Journal of Applied Ecology
Observational study
Animals
Local canopy cover, shade tree identity and landscape tree cover shape density and herbivory in cacao agroforestry systems
23-Apr-2026
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.