Pathogenic nature of Syncephalastrum in Atta sexdens rubropilosa fungus gardens

Author(s)

Barcoto, Mariana O. ; Pedrosa, Felipe ; Bueno, Odair C. ; Rodrigues, Andre

• Document type: Journal article
• Source: Pest Management Science; v. 73, n. 5, p. 999-1009, MAY 2017.
• Web of Science Citations: 5

Abstract

BACKGROUND: Leaf-cutter ants are considered to be a major herbivore and agricultural pest in the Neotropics. They are often controlled by environmentally persistent insecticides. Biological control using pathogenic fungi is regarded as an alternative for the management of these insects. Here, we assess whether the filamentous fungus Syncephalastrum sp. is a pathogenic microorganism responsible for a characteristic disease in fungus gardens. We also characterise the damage caused by this fungus by evaluating physiological and behavioural responses of Atta sexdens rubropilosa subcolonies infected with Syncephalastrum sp. RESULTS: Syncephalastrum sp. fulfils Koch's postulates characterising it as a pathogenic microorganism. Ant workers recognise the infection and remove contaminated fragments from the fungus garden. Syncephalastrum sp. infection causes an interruption of foraging activity, an increase in ant mortality, subcolony deterioration and an increase in the amount of waste generated, all resulting in subcolony death. Syncephalastrum sp. also inhibits the ant fungal cultivar in vitro. The pathogenic effect of Syncephalastrum sp. does not depend on host morbidity or stress (e.g. worker mortality caused by an entomopathogenic fungus). CONCLUSIONL Syncephalastrum sp. treatment resulted in progressive damage in subcolonies. The interactions among Syncephalastrum sp., fungus garden and ants offer new opportunities in integrated pest management of leaf-cutter ants. (C) 2016 Society of Chemical Industry (AU)

• FAPESP's process: 11/16765-0 - DNA barcoding and biotechnological potential of microfungi associated with leaf-cutting ants
• Grantee: André Rodrigues
• Support type: Research Grants - Young Investigators Grants
• FAPESP's process: 13/10398-1 - Pathogenicity of Syncephalastrum racemosum towards leafcutter ant nests
• Grantee: Mariana de Oliveira Barcoto
• Support type: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 12/02177-2 - The role of Syncephalastrum racemosum as antagonist of the leaf-cutting ant cultivar
• Grantee: Felipe Pedrosa Chagas
• Support type: Scholarships in Brazil - Scientific Initiation