Product description: Bt has a two-pronged attack. The crystalline inclusion body produced by the organism (known as the δ-endotoxin) dissolves within the gut of the insect after ingestion. The digestate attacks the cells of the insect midgut; causing swelling, distortion and eventual bursting. The lesions within the gut cause the death of the insect. Spores can germinate within the gut and multiply to produce further quantities of endotoxin. Bt has no contact or systemic activity.