O potencial das formigas-cortadeiras-de-folhas (Atta laevigata) na remoção de carcaças de ratos (Rattus norvegicus)

Abstract

The decomposition of a living being is an immutable process of utmost importance for nutrients to remain in the ecosystem, allowing other organisms to benefit. Among those seeking this resource for their development, insects are particularly relevant due to their broad dietary flexibility and habitat range. Currently, the majority of studies focusing on insects associated with decomposing carcasses are primarily concentrated on the orders Coleoptera and Diptera, while others such as Hymenoptera remain in the shadows, needing greater visibility. Ants (Hymenoptera: Formicidae) are among the first organisms to arrive at a dead animal and remain throughout the decomposition process, modifying the carcass's decay rate both through their own actions and through competition and predation with other insect species. Thus, this study aims to understand the role of ants in the animal carcass decomposition process by quantifying biomass loss over 72 hours and decay rate over this time interval. For this purpose, Atta laevigata ants were used as a model species, given their prevalence in the Cerrado biome and their documented importance in previous literature, and Rattus novergicus carcasses as they are easily accessible mammals. The experiment consisted of two treatments: one where the carcass was placed alongside Atta trails, and another where these and other ants were excluded by using a plastic ring and entomological glue. Biomass loss and decay rate were measured daily for all treatments over 72 hours, with 12 carcasses per week over four weeks, totaling 48 carcasses. The results confirm the relevance of Atta laevigata in the decomposition process, showing a clear increase in the speed of mass loss and carcass decay rate in the presence of these ants compared to their absence. Furthermore, it underscores the need for increased research involving Atta ants, as well as other Formicidae species, as there are few studies using them as models despite their significant and notable importance in decomposition ecology.