Diversity in gut microflora of Helicoverpa armigera populations from different regions in relation to biological activity of Bacillus thuringiensis δ-endotoxin Cry1Ac.

Transgenic crops expressing toxin proteins from Bacillus thuringiensis (Bt) have been deployed on a large scale for management of Helicoverpa armigera. Resistance to Bt toxins has been documented in several papers, and therefore, we examined the role of midgut microflora of H. armigera in its susceptibility to Bt toxins.