A study was conducted to understand the effects of Lantana camara extract concentration and fermentation period of Bacillus thuringiensis on the mortality of Setora nitens (Lepidoptera: Limacodidae), it’s also to determine the most effective biopestisides formulation against the S. nitens. A full-factorial experiment was arranged in 3x2 factors: first factor was L. camara extract with varied concentration of 5 %, 10 %, 15 %; second factor was fermentation period at 3 days and 6 days. Observed parameters on this study were cellulose and alkaloid content of L. camara after fermentation, the population dynamics of B. thuringensis during the fermentation, body weight and mortality of S. nitens. The results indicated that cellulose and alkaloid content increased at 5 % L. camara with 3 days fermentation. However, the population dynamic of B. thuringensis increased at 10 % L. camara during 3 and 6 days fermentation. It’s indicated that 10 % L. camara has adequate nutrition for supporting the growth of B. thuringensis. Moreover, the mortality of S. nitens was highest at 10% L. camara and 3 days fermentation, which mortality rate was 4,6 individual/day and the mortality percentage was 83%. The study can be concluded that the best pesticides formulation againts S. nitens was 10 % L. camara fermented by B. thuringensis for 3 days.