Isolation and Bioassay of Insect Pathogenic Bacteria in the Rhizosphere of Soybean Crops in Dry Land Central Lombok

Abstract

Spodoptera litura are able to destroy 1,5 hectares of soybean crops in 12 hours. The control of this S. litura by using pathogenic bacteria of insects are more efficient compare with using synthetic chemical insecticide. The exploration of pathogenic bacteria of insects is conducted on rhizosphere of soybean crops in dry land. The bacteria are isolated with heating technique and selective medium. Of pathogen bacteria are obtained 9 isolations bacteria, 4 isolations are obtained by the method of heating at 80 ° C for 10 minutes and 5 isolations are gain used selective medium King's B tested for the ability to control S.litura. The screening process is held by measuring remaining larva feed and percentage of dead larva in concentration of .32x10 9 CFU/ml. Remaining larva feed caused by bacteria achieve the number of 9.08 gram and larva mortality percentage is 94.66% in 162 hours.