Name the pest that destroys the cotton balls.Explain the role of Bacillus thuringiensis in protecting the cotton crop against the pest to increase the yield

Species of Lepidoptera, Diptera, Coleptera. etc.
The cry gene of B. thuringiensis was found to express proteinaceous toxin inside the bacterial cells. When specific insects ingest the toxin, they are killed. The toxin denatures the epithelium of gut by creating many holes at alkaline pH(7.5-8).
In India Bt-cotton was permitted to sow at large scale in fields.