Explain how the pH of the gut of caterpillar is sustained acidic rather than basic (alkaline) and they are subjected to cry-Protein produced by Bacillus thuringiensis?

Explanation

Bacillus thuringiensis toxin protein (Cry-protein) exists in its inactive form as protoxin. When it enters the gut of the caterpillar then in the alkaline pH, it gets activated (toxin). It becomes soluble, attaches to the wall of the gut, causes swelling and lysis. There is no alkaline pH in the gut, no activation of pro-toxin, toxin ineffective, caterpillar would not die.