Occurence of Metarhizium anisopliae Var. anisopliae on Sugarcane Internode Borer,Chilo sacchariphagus indicus (Kapur)

Abstract

Metarhizium anisopliae var. anisopliae is found on the larvae of sugarcane internode borer, Chilo sacchariphagus indicus (Kapur) under field conditions at Coimbatore. In laboratory tests, the fungus caused 20.0 to 83.3 per cent mortality in third instar larvae and 10.0 to 90.0 per cent mortality in fourth instar when treated with different doses ranging from 10⁴ to 10⁹ spores/ml. The time taken to kill the larvae varied from 5.6 to 13.1 days in third ins tar and 5.9 to 9.9 days in fourth instar. The mean number of spores produced per dead larva varied from 0.17 í— 10⁹ to 0.48 í— 10⁹ in third instar and 0.92 í— 10⁹ to 1.52 í— 10⁹ in fourth instar.