Herbivores just need a calm place to feed: Ants cannot help them

Abstract

Why do herbivores, like Coelomera sp., seek to consume leaf tissue of Cecropia pachystachya colonized by Azteca alfari Emery, 1893 if they are at risk of being attacked by these ants? We collected herbivory data (leaf area lost, occurrence of herbivores and expulsion of enemies by A. alfari) in different shifts (times of the day) in 50 C. pachystachya trees (25 uncolonized and 25 colonized by A. alfari). We registered less leaf area lost and less beetle occurrence in colonized plants. Moreover, the proportion of enemies expelled (killed or removed) is more related to the number of ants that were patrolling and attacking the invaders in the tissue than to the total number of ants present in colonized plants due to A. alfari recruitment and behavior. Thus, such herbivores prefer to use tissues of uncolonized plants and tree structures of colonized ones with less active ants given the risk evaluation of encountering a group of aggressive ants. In this way, C. pachystachya needs these ants to cover the plant tissues as much as possible to ensure its protection.