Screening of Fungi Isolated from the Brazilian Restinga for Insecticidal Activity
Vicente Mussi-Dias *
Laboratory of Chemistry and Biomolecules (LAQUIBIO), CENSA - ISECENSA Superior Education Institutes, Rua Salvador Correa, 139, Centro, Campos dos Goytacazes, RJ, CEP: 28035-310, Brazil and Laboratory of Entomology and Plant Pathology LEF/CCTA, Northern Rio de Janeiro State University Darcy Ribeiro – UENF, Av. Alberto Lamego, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, CEP: 28013-602, Brazil.
Maria das Graças Machado Freire
Laboratory of Chemistry and Biomolecules (LAQUIBIO), CENSA - ISECENSA Superior Education Institutes, Rua Salvador Correa, 139, Centro, Campos dos Goytacazes, RJ, CEP: 28035-310, Brazil.
Adão Valmir dos Santos
Laboratory of Biotechnology - LBT/CBB, Northern Rio de Janeiro State University Darcy Ribeiro – UENF, Av. Alberto Lamego, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, CEP: 28013-602, Brazil.
Denise Dolores Oliveira Moreira
Laboratory of Entomology and Plant Pathology LEF/CCTA, Northern Rio de Janeiro State University Darcy Ribeiro – UENF, Av. Alberto Lamego, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, CEP: 28013-602, Brazil.
Aline Teixeira Carolino
Laboratory of Entomology and Plant Pathology LEF/CCTA, Northern Rio de Janeiro State University Darcy Ribeiro – UENF, Av. Alberto Lamego, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, CEP: 28013-602, Brazil.
Richard Ian Samuels
Laboratory of Entomology and Plant Pathology LEF/CCTA, Northern Rio de Janeiro State University Darcy Ribeiro – UENF, Av. Alberto Lamego, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, CEP: 28013-602, Brazil.
*Author to whom correspondence should be addressed.
Abstract
Research on microorganisms for the control of pests and pathogens is increasing. Such organisms display antagonistic effects on pests and pathogens, at the same time, they do not interfere with the sustainable development processes and are environmentally safe for human populations. Thus, bioprospection of fungi from restinga ecosystems is of interest as a novel source of microorganism and a yet unexplored source of chemical structures. This study selected endophytic fungi and fungi from the restinga soil samples to investigate their biological activity against insects. Fifty-three fungal isolates were used in screening bioassays against Atta sexdens rubropilosa leaf-cutting ant workers via direct contact of the insects with sporulating fungi cultures. This assay indicated that Trichoderma caused the highest mortality. Extracts from Trichoderma were then assessed for biological activity via ingestion, contact or exposure to fungal volatiles. Results showed that one Trichoderma sp. isolate (TR1) caused 50% mortality in 2, 1.5 and 4 days when ingested, sprayed onto the ants or by exposing ants to volatiles, respectively. Although this fungus is not known to be entomopathogenic, it could have potential use as an additional tool for pest control as it produces metabolites with antagonistic effects.
Keywords: Biodiversity, toxicity, biological control, bioactive compounds.