Resíduo de malte e bagaço da cana-de-açúcar: substratos alternativos para produção do fungo entomopatogênico Metarhizium anisopliae var. anisopliae (Deuteromycotina: Hyphomycetes).

Abstract

Metarhizium anisopliae is used in the biological control of several pest insects in agriculture. The production costs of its conidia, on a large scale, in the standard substrate (rice) currently used, affects the production process. Finding alternatives as a way of minimizing process costs has led to the need to ascertain the efficiency of alternative substrates. Therefore, our objective was to analyze the potential of agroindustrial residues for the production of M. anisopliae and to evaluate the viability of the conidia produced in cutter ants of the genus Atta. The experiment for conidia production was performed in erlernmeyer containing γ0 g of the substrates and 0.γ μL of the conidial suspension (1 x 108 conidia/mL). After 10 days of incubation, an aliquot of conidia of 1 x 108 conidia/mL was collected and placed in a Petri dish containing moistened filter paper and the ants. An experiment was performed with three replicates, plus the control group. The viability of the conidia of M. anisopliae produced in the different substrates was guaranteed by the mortality of the infected ants. The mean mortality rate from the conidia produced on the three substrates was 99.9% (rice), 96.4 (malt) and 77.9 (sugarcane bagasse). Considering the results obtained, the alternative substrates used (malt residues and sugarcane bagasse) for M. anisopliae growth have potential for conidiogenesis and consequently can provide a 50 % reduction in M. anisopliae production costs.