Diversity of Gut Bacteria in Spodoptera litura (F) and Helicoverpa armigera (Hubn) Larvae

Gut bacterial diversity in field and laboratory strain of S. litura and H. armigera was studied USING Denaturing Gradient Gel Electrophoresis (DGGE) analysis. Results showed that field collected larvae found to be had more diverse of gut bacterial community with greater Shannon diversity index and Operational Taxonomic Units (OUT’s) as compared to laboratory strain. Shannon diversity index of field collected S. litura and H. armigera larvae recorded were 1.89 and 2.60 for the primer pair PRBA338-PRUN518 respectively. While another primer pair E1052-E1193 recorded Shannon diversity index of 2.65 and 2.03 respectively. On the contrary laboratory reared larvae of S. litura recorded Shannon diversity index of 1.60 for PRBA338-PRUN518 primer pair and 2.20 for E1052-E1193 primer pair. Shannon diversity index for H. armigera was 2.02 and 1.09 against PRBA338-PRUN518 and E1052-E1193 primer pairs respectively. With respect to Operational Taxonomic Units (OUT’s) again field collected test insect larvae shown higher OUT’s for both primer pairs. Field collected S. litura larvae shown 17.20 OUT’s for PRBA338-PRUN518 primer and 13.60 OUT’s for E1052-E1193 primer pair. Similarly Field collected H. armigera larvae shown 21.00 OUT’s for PRBA338-PRUN518 primer and 15.00 OUT’s for E1052-E1193 primer pair. Whereas laboratory reared larvae of S. litura recorded 9.00 OUT’s for PRBA338-PRUN518 primer and 11.40 OUT’s for E1052-E1193 primer pair and another test insect H. armigera recorded 11.00 OUT’s for PRBA338-PRUN518 primer and 7.40 OUT’s for E1052-E1193 primer pair. DGGE analysis indicated that field strains of both test insects showed more diversity in gut bacteria as compared to laboratory reared strains.