Mode of Action
Bacillus thuringiensis (Bt) is a rod-shaped, spore-forming microorganisms used to control target insects in a manner that is both highly effective and environmentally benign. Bt are naturally-occurring throughout most regions of the world. They are common in soil and on plant leaves and are biodegradable.
The active ingredient in DiPel is proprietary strain of Bacillus thuringiensis subsp. kurstaki (Btk). VBC’s proprietary Btk Strain ABTS-351 is high yielding strain that produces a uniquely balanced blend of four Cry toxin proteins – Cry1Aa, Cry1Ab, Cry1Ac, and Cry2 – plus Bt spores. Cry toxins are lethal to many pest and disease-carrying insect species, such as caterpillar, beetle, and mosquito larvae. Cry toxins are also harmless to humans, birds, pollinators, and other beneficial wildlife.
The active ingredient in XenTari is a proprietary strain of Bacillus thuringiensis subsp. aizawai (Bta). VBC’s proprietary Bta Strain ABTS-1857 is high yielding strain of that produces a uniquely balanced blend of four Cry toxins, slightly different than the combination found in DiPel. The Cry toxins produced by Bta are Cry1Aa, Cry1Ab, Cry 1C, and Cry 1D. This combination is particularly effective against Armyworm populations.
Cry toxins act as selective stomach poisons with target insect. Spores contribute to their toxicity by causing blood poisoning and providing environmental persistence.
When an insect pest ingests Cry proteins from treated leaves, its feeding stops within minutes. The protein crystals are solubilized in the gut of the pest and gut cells are irreparably damaged. Once this damage occurs, Bt spores enter through the gut wall and germinate rapidly in the body cavity causing blood poisoning. The larvae then die in 1-3 days.
Affected larvae move slowly, discolor, then shrivel, blacken, and die. Smaller larvae die more quickly, which suggests that precise timing can measurably improve the performance of the application.
Some pest species are can be difficult to control with toxins alone. The germinating Bt spores found in VBC products provide an additional control mechanism and have a distinct advantage over Bt products without spores.