Interação entre larvas de Rhinoleucophenga myrmecophaga (Diptera: Drosophilidae) e formigas em frutos com nectários pericarpiais de Cordiera elliptica (Rubiaceae) no cerrado

Abstract

Extrafloral nectaries (EFN) are very important structures in insect-plant interaction because they can attract predatory ants that will defend plants against herbivorous attack. However, other insects have specialized in the use of this resource, such as larvae of a species of Diptera that grow in the EFNs of some plants and prey on ants that forage in these structures. In this sense, the objective of this study was to verify if larvae of Rhinoleucophenga myrmecophaga (Diptera: Drosophilidae) have any effect on the fitness (development and production of fruits) of Cordiera elliptica (Rubiaceae), a Cerrado plant. Additionally, it was verified if the absence of ants influences the larval development and survival. The study was carried out in a cerrado sensu stricto area between September 2018 and January 2019, where fruit development, as well as the development of R. myrmecophaga larvae, were evaluated in three experimental groups: with the presence of larvae of the fly, and adult ant workers; without the presence of ants; and without the presence of larvae. The results showed that: C. elliptica fitness is negatively influenced by the presence of R. myrmecophaga larvae; the presence of larvae decreased ant abundance; the absence of ants negatively influenced larval development; fruits with larvae and without ants presented lower volume and weight. Thus, we show that the results of the multitrophic relationship between ants, R. myrmecophaga larvae, and a plant bearing EFNs on fruits are directly and indirectly influenced by predatory larvae, which indicates conditional results of this multitrophic relationship.