Coleopteran-active cry gene profiling and insecticidal activity of indigenous Bacillus thuringiensis strains against Holotrichia serrata.

Indigenous Bacillus thuringiensis strains from India's Western Ghats show high insecticidal activity against Holotrichia serrata, with strain NBAIR Bt68 causing 73% larval mortality.

• Why it matters: Controlling the subterranean pest H. serrata with chemicals is often ineffective, highlighting the need for sustainable biological alternatives to protect crops and reduce yield losses.
• What they did: Researchers screened 100 B. thuringiensis strains for 12 coleopteran-active cry genes using PCR and evaluated their insecticidal activity through bioassays, identifying highly toxic strains and gene combinations.
• The result: Strain NBAIR Bt68 was the most virulent, with an LC80 of 149.95 μg/mL, and strains with cry7, cry26, cry34, and cry35 genes consistently showed high toxicity, suggesting potential for biocontrol applications.