Patogenisitas Isolat Beauveria Bassiana (Balsamo) Vuillemin Dalam Mengendalikan Hama Penggerek Bonggol Pisang, Cosmopolites Sordidus Germar

Abstract

. This experiment was conducted at the labora- tory of Entomologiy, Indonesian Fruit Research Institute from May to October 2002. The soil samples were collected from banana production centers at Baso, Sei Tarab, Sei Sariek and Sikabau. The objectives of this experiment were to investigate the influence of spore dose on the infectivity of the isolates against adult and the susceptibility host of im- mature stages and mature stage of banana weevil which were treated with B. bassiana isolates. A completely random- ized design with twelve treatments and three replications were used in this study. The result showed that the effectiveness of the B. bassiana from four isolates increased with increasing spore dose. There was a significant differ- ent in infectivity of all isolates of B. bassiana. The adult banana weevil mortalities caused by entomopathogen fungi of B. bassiana isolate from Baso, Sei Tarab, Sei Sariek and Sikabau at highest density (3.2X108 conidia/ml) after two weeks were 96.67%, 90.00%, 60.00%, and 83.33% respectively. The aqueous suspension of B. bassiana conidia from isolate Baso was the lowest with LC50\u27s of 1778289 conidia/ml and a Lethal time 50\u27s was faster 7.22 days compare than other isolate. It means that isolate B. basiana from Baso has higher patogenicity than other isolate. The mortality of banana weevil stages ranging from 76.67% to 100% at 15 days after inoculation of B. Bassiana. Mortality of larva at the second stadia was relatively higher compared to the other stadia of banana corm borers. This study was undertaken to provide more information on the potential for developing B. bassiana as a control agent for the banana weevil borer