The use of Metarhizium anisopliae var. acridum against the grasshopper Rhammatocerus schistocercoides in Brazil
B.P. MAGALHÃES, M.R. DE FARIA, M. LECOQ, F.G.V. SCHMIDT, J.B.T. SILVA, H. S. FRAZÃO, G. BALANÇA, A. FOUCART
(BPM, MRF, FGVS, JBTS, HSF) Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica - Final W5 Norte, Brasília-DF, CEP 70770-900, Brazil.
(ML, GB, AF) GIRAD, Dépt. AMIS - Programme Protection des Cultures - Prifas, TA40/D, Campus International de Baillarguet, 34398 Montpellier Cedex, France. E-mail: email@example.com
The control of grasshoppers in Brazil has been based exclusively on chemical insecticides (fenitrothion and malathion). However, as these products are known to be harmful to the environment, their massive use has caused concerns. In the face of pressure, against their use, the development of alternative methods became imperative. Some species of entomopathogenic fungi can supplement or even replace chemical insecticides in the control of grasshoppers. An integrated research project began in Brazil in 1993 with the specific objective of developing bioinsecticides based on entomopathogenic microorganisms, especially fungi, to control grasshoppers. Activities centered in surveys, characterization, production, formulation, and field evaluation. Emphasis was given to developing the fungus Metarhizium anisopliae var. acridum as the most promising biocontrol candidate. It is now known that this pathogen can be used efficiently in the control of Rhammatocerus schistocercoides in Brazil and we are verifying its effects on non-target organisms, including other Orthoptera, Diptera and Hymenoptera.
Grasshoppers, mycopesticide, fungus, Brazil
In past years, native species of grasshoppers have caused severe losses to crop systems in Brazil through seasonal outbreaks determined by environmental conditions. There are at least 23 species of grasshopper considered potential pests. The most serious outbreak occurred from 1984 to 1988 in Mato Grosso State, Central West Brazil, where Rhammatocerus schistocercoides (Rehn) invaded approximately 2 million ha. It seems that grasshopper outbreaks are mostly associated with the rainfall regime, especially from August to October; a critical period for the grasshopper cycle (Miranda et al. 1996). Outbreaks of different species were also recorded in other regions. In the south, Rio Grande do Sul State, Rhammatocerus conspersus (Bruner) invaded ca 50,000 ha in 1991/1992 (Cosenza et al. 1994). In the northeast, outbreaks of Schistocerca pallens (Thunberg) were recorded many times (1888, 1985, 1996). In the last two years, a species complex has attacked pastures in Minas Gerais State during the rainy season, moving to banana orchards nearby during the dry season.
An integrated research project was initiated in Brazil in 1993 at Embrapa (Brazilian Agricultural Research Corporation) Genetic Resources and Biotechnology, with the specific objective of developing bioinsecticides based on entomopathogenic microorganisms, especially fungi, to control grasshoppers. Our activities have included surveys, characterization, production, formulation, and field evaluation. Emphasis has been given to develop the fungus Metarhizium anisopliae var. acridum as the most promising candidate found as biocontrol agent against grasshoppers in Brazil .
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