Some studies on the use of Metarhizium anisopliae (Metsch.) Sor. for the control of Oryctes rhinoceros in Sri Lanka

Abstract

Black beetle, oryctes rhinocers L. larvae and adults were inoculated in the laboratory with three isolates of the fungus Metarhizium anisopliae (Metsch.) Sor, to screen their virulence against black beetle. ALl the isolates caused 100 per cent mortality of larvae and adults when treated with suspensions of 10(7) conidia/ml. Comparatively the local isolate caused a slow death rate in larvae and adults than the other isolates. Fifty grams of the maize inoculum per 0.008 m2 of breeding medium were sufficient to cause 100 per cent death rate of larvae. In the field, the fungus was capable of disseminating at least 10 m and the impregenation boxes (infection foci) were attractive to black beetle. It is suggested that M.anisopilae could be used as an effective bio-control agent in the intergrated management of black beetle.