Abstract: Locally available sugar cane molasses was utilized in the production of bioinseticide by cultivating four strains of Bacillus thuringiensis (B.t) namely H-D 133, H-D 234, ENRC 60 and ENRC 63 under shaking culture. The highest yields obtained after 90 hour fermentation. Total viable counts, total spores and percent of spores were different between the four strains. The by product whey ultrafiltrate was utilized in spore crystal mixture recovery from the fermentation beer of the tested strains. Adjusted fermentation beer to pH 7.0 and pH 4.0 prior recovery showed the advantage in spore an crystal mixture recovered yield when the fermentation beer was adjusted to pH. 4.0 Comparison between lactose solution and whey ultrafiltrate contained the same amount of lactose for spores-crystals mixture recovery from fermentation beers showed increases in the yield where in whey ultrafiltrate was employed. Bioassay against the larvae of Spodoptera littoralis, Spodoptera exigua Phthorimaea operculella and Earias insulana were performed. The LC50, slopes, 95% confidence limits and potencies for both two spore-crystal mixtures obtained by lactose solution or whey ultrafiltrate of the four strains were determined. The bioassay showed that the larvae of potato tuber moth and spin boll worms were highly sensitive to the four produced pathogen than S. littoralis and S. eixigua. The spore-crystal mixture recovered in the presence of whey ultrafiltrate showed high toxic effect against the assayed larvae of S. exigua, E. insulana and S. littoralis, whereas, the recovered spore-crystal mixture in the presence of lactose solution was more toxic for P. operculella.