LEAF-CUTTING ANTS: ECOLOGICAL ASPECTS AND RENEWAL RATE OF THE FUNGUS GARDEN BY STABLE ISOTOPES TECHNIQUE

• Grant number: 12/08134-3
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: July 01, 2012
• End date: June 30, 2015
• Field of knowledge: Biological Sciences - Zoology
• Principal Investigator: Luiz Carlos Forti
• Grantee: Paula Corrêa Dias
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Ants of the genus Atta are social insects with great importance to humans and the environment, having an important role in the flow of energy and nutrients, and also standing out as agricultural pests. These insects, growers mandatory of the symbiotic fungus, which they feed, cut leaves and other parts of plants growing for hundreds of meters away from the nest, for the maintenance of the fungus garden. The ant Atta bisphaerica, which has limited distribution in Brazil, uses predominantly grass species in their foraging, but eventually can cut dicots, being one of the most economically important insects to cause significant losses in production systems in agriculture, livestock and forestry, resulting in serious economic losses. However, this species of ants, as well as other species of ants, can bring benefits to the habitat where they nests are inserted into. Although the effect of defoliation can reduce performance or even kill the plants get to cut, the colonies of Atta concentrate enormous amounts of material rich in nutrients, transporting it into the nest, and also created an underground chamber to deposit the trash nest, contributing to a substantial increase in the concentration of macronutrients and soil penetrability compared to soils without nests. Thus, the aim of this study is to investigate some ecological aspects of this specie of leaf-cutting ant in order to elucidate some aspects about the beneficial effects of the habitat in which they operate. For this, experiments will be conducted to evaluate the impact of this species in pastures associated with nests; to observe the time taken to complete degradation of the waste and subsequent return of nutrients to the soil; as well as isotopic analysis of carbon - 13 of the nest and all its members (eggs, larvae, adults, fungus and litter), in order to acquiring knowledge about the renewal rate of the fungus garden.