Density, Viability Conidia And Symptoms of Metarhizium anisopliae infection on Oryctes rhinoceros larvae

Abstract

M. anisopliae is parasitic fungus on insect pests; it is used as a biocontrol agent. M. anisopliae can be propagated on maize or rice substrate. M. anisopliae is currently sold in the form of kaolin powder formulations. Before it is used to check the density, viability and pathogenicity of M. anisopliae. However the problem is the kaolin powder very soft, so it difficult to distinguish between kaolin and conidia. This article gives information on how to calculate conidia density, viability and symptoms of M. anisopliae infection on Oryctes rhinoceros larvae. The study was conducted in the laboratory to determine the density and viability. The pathogenicity testing was done using pots. The Pot is containing soil substrate mixed with M. Anispoliae and ten tails O. Rhinoceros larvae per pot. The results showed that the density of M. anisopliae conidia was 1.81 x 108 conidia mL-1 and the viability was 94% within 24 hours. The larval mortality began to emerge in the 1st week, and all larvae died at the sixth week. The symptom of M. anisopliae infection on Oryctes rhinoceros larvae, there was a black spot on the larval integument. The larvae movements become slow and poor appetite; it will die within 3-7 days. The larvae die hard, and the white hyphae grow on the body surface that turns green.