Evaluation of entomopathogenic fungi encapsulated in pectina matrix to control of Atta sexdens (Linnaeus, 1758) (Hymenoptera, Formicidae)

• Grant number: 19/12657-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2020
• End date: November 30, 2020
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Ricardo Toshio Fujihara
• Grantee: Erick Sekiama Rocha
• Host Institution: Centro de Ciências Agrárias (CCA). Universidade Federal de São Carlos (UFSCAR). Araras , SP, Brazil

Abstract

We know that the main form of the leaf-cutting ant control (Atta and Acromyrmex genera) is by means of granulated baits a based in sulfluramid. However, this is a method that can lead to environmental and health problems. The biological control with entomopathogenic fungi can be an effective, safe and ecologically sustainable alternative. However, due to the difficulty in development an efficient vehicle of contamination, the use of these biological agents is not yet a reality. In a pilot experiment, we evaluated the compatibility of encapsulates constituted by pectin (a biopolymer) and citrus pulp (attractive), and we have observed that they were incorporated by Atta sexdens workers in the fungus garden, without rejection, demonstrating its use potential. In this way, we will develop a pectin-based encapsulation, able to carry and maintaining metabolically viable, entomopathogenic fungi, preserving their potential contamination. In laboratory, we will evaluate the ideal concentrations of pectin and citrus pulp, and the temperature range to maintain the viability of the selected fungi. Subsequently, we will produce encapsulated in pectin matrix with the attractive and the fungal suspension of the different isolates. The design will consist of the following treatments: encapsulated without entomopathogenic fungus - control, Beauveria bassiana, Metarhizium anisopliae, Isaria farinosa, and sulfluramid - standard formicide at 0.3% of the active ingredient. We will evaluate the transport and incorporation of encapsulates, as well as the mortality of Atta sexdens workers. The results can generate subsidies for future studies involving the microbial control of leaf-cutting ants, viabilizing a more sustainable agriculture.