Bagworm control with broad-spectrum contact insecticides has often disrupted the balance between the insect and its natural enemies – its predators, parasitoids and microbial pathogens. Most chemical insecticides also affect non-target organisms, and their residues often persist in the environment. The insecticidal proteins of Bacillus thuringiensis (Bt) are very target specific. Active ingredients of Bt are mixture of spores and crystals. The spores and crystals of Bt are produced aerobically via liquid fermentation. They are easily harvested and, when properly formulated, have a long shelf-life (Ghribi et al., 2006a). Bt typically produces δ-endotoxins in parallel with spore formation during the stationary phase of the cell growth cycle (NPTN, 2004). The δ-endotoxins, after ingestion by susceptible insect larvae, are activated by the gut proteases (Ghribi et al., 2006b). The activated toxin binds with the gut receptor and causes osmotic lysis and death of the larvae. Flowable Bt concentrate, Lepcon-1, is produced by vacuum evaporation of fermented liquid culture at 33o C. This new Bt product has a shorter production cycle as compared to the wettable powder, Terakil-1.

Main Research: Mohd Najib Ahmad