This research aims to examine the effect of density of B bassiana on the control of caterpillar Grayak S. litura F on soybean crop. This research was conducted at Pest Laboratory of Agricultural Faculty of Syiah Kuala University and continued field research in experimental garden of Faculty of Agriculture of Jabal Ghafur University in Sigli, Pidie Regency from August to October 2015. This research uses non factorial RAL design, with fungi density consist of 5 levels: (105, 106, 107, 108 and 109 / mL) with 4 replications so that there are 20 experimental units. The parameters observed in the invitro were cytomatology, the number of pupa, the number of imago and mortality and the observation in the field regarding to mortality and intensity of attack. Laboratory test results on the symptomatology that the mycelia of the insect body began to appear on the 4th day, and the seventh day of the entire body of S. litura was almost covered by white dyed mycelia. To be able to kill up to 50% of the population, it takes 5 days and 95% death takes 10 days and percentage of mortality (90%), pupa is formed (10%) and imago amount (10%) The best treatment of conidia density is found at 109 / mL(E). Results of field observations on the percentage of mortality (90%) and the intensity of attacks (21%). The best treatment of conidial density was found at a 109 / mL (E).
Keywords: the density of fungus; B. bassiana S litura; soybean