Chemical contents of Macaranga food bodies: adaptations to their role in ant attraction and nutrition

1. Macaranga (Euphorbiaceae) is a paleotropical tree genus comprising myrmecophytic and non-myrmecophytic species. All species are presumed to possess food bodies (FBs) to maintain or attract ants as anti-herbivore defence. 2. The hypothesis was tested that Macaranga species differing in their mode of association with ants would produce FBs differing in their chemical composition. We investigated contents of carbohydrates, proteins and lipids in FBs of four myrmecophytic and one non-myrmecophytic Macaranga as well as one Parthenocissus (Vitaceae) species. 3. On a dry weight basis, FBs of myrmecophytes contained relatively higher amounts of proteins compared to carbohydrates than those of non-myrmecophytes, Soluble carbohydrates showed species;specific patterns and were found in especially high amounts in both non-myrmecophytes. Furthermore, Parthenocissus FBs contained higher amounts of soluble compared to polymerous substances not only in carbohydrates but also in proteins. 4. FBs seem to be specifically adapted to their respective role in ant attraction and nutrition, with myrmecophytes providing ants with high amounts of lipids and proteins and non-myrmecophytes mainly offering carbohydrates in the form of common soluble sugars.