Importance of chemical and geographical distances in determination of ant’s aggressive behavior: first insight in the Cecropia-Azteca system

• Ano de defesa: 2019
• Autor(a) principal: Neves, Gabriela Zorzal
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Mutualismo; Azteca muelleri; Ecologia química; Formigas - Comportamento; Ecologia Teórica
• Link de acesso: https://locus.ufv.br//handle/123456789/28503

Territorial animals respond less aggressively to intrusions by neighbors than by outsiders. This difference in behavioral responses is termed “dear-enemy phenomenon” and it determines recognition and aggressiveness in animal interactions. In social insects, the identification of non-nest mates is mainly performed through "colony odors", formed by hydrocarbon lipid compounds that cover the insects’ cuticle (also called CHCs). The difference in the chemical composition of these compounds may be genetically influenced and influenced by the environment and/or by the diet of colony individuals. Myrmecophytic ants present an aggressive defensive behavior against plants natural enemies. These systems might be considered a promising model for studying nest-mate recognition and aggressiveness behaviors. Thus, the present study aims to experimentally test the importance of geographical and chemical distances on the aggressive behavior among individuals of Azteca muelleri ants inhabiting Cecropia glaziovii plants. We sampled a total of 50 ant colonies in three Atlantic Forest fragments located in the Viçosa municipality, state of Minas Gerais, Brazil. The distance in meters between sites were estimated using the GPS data provided from the two points of interest. After sampling, we performed aggression tests using five works from the same colony against five workers from other colony. Each colony was used only once. For the aggression tests we divided the 50 colonies in two distinct groups: same location group and different location group. Then, we observed the behaviors of ants in each aggression test and we classify them as non-aggressive and as aggressive. After the aggression tests, we identified picks of chemicals compounds (CHCs) and evaluated the concentrations of these components by chemical analysis. Our results showed a positive effect of geographical distance on ant aggressiveness and a significantly higher aggressiveness between pairs of ants from different site when compared to pairs of ants belonging to the same site. On the other hand, A. muelleri aggressiveness was not influenced by chemical cuticles profile and we alsov did not detect a significant interaction between geographical distance and chemical distance. The Azteca-Cecropia system therefore exemplifies a relationship in which the geographic distance influences the aggressive behaviour. However, in this system the total of chemical compounds does not explain the aggression behaviour and only some these compounds may play a main role in the aggressive behaviour and non-nest mate recognition. Thus, it is necessary to investigate if these factors and others parameters such as genetic distance, may be influencing the aggressive behaviour in this species of Azteca.