Diversity of Culturable Bacteria in Gut of White Grub Maladera insanabilis (Brenske)

Maladera insanabilis (Brenske) (Scarabaeidae: Coleoptera) is an economically important insect pest in agricultural and horticultural ecosystems. Digesting lignocellulolytic material has physiological and developmental benefits and requires microbial interaction for nutrient synthesis and utilization. Using a culture-dependent approach, we characterized the diversity of gut bacteria from different gut compartments of M. insanabilis larvae. Under aerobic culture conditions, the colonization of gut bacteria in the foregut revealed significantly higher CFU count on Nutrient agar (2.400x10⁶± 0.206) followed by Bacillus cereus agar (2.743 x10⁶± 0.147) and Nitrate agar (2.403 x10⁶± 0.219) respectively. The hindgut recorded the highest CFU count of (2.780 x106± 0.031) on Thioglycolate media under anaerobic conditions. In the gut compartments of M. insanabilis larvae, there were eighteen culturable aerobic gut bacterial isolates belonging to phylum Bacillota and Pseudomonadota, and eight facultative anaerobic gut bacteria belonging to phylum Bacillota, and Pseudomonadota were found. The percentage abundance of the aerobic and anaerobic gut bacteria revealed that the genus Bacillus was the most abundant genera in the midgut (27.77%) and hindgut (25%), respectively. The foregut showed significantly higher Shannon (1.797±0.012) and Simpson (0.164±0.010) diversity for aerobic gut bacteria whereas anaerobic gut bacteria in the hindgut revealed significantly higher Shannon ((1.095±0.002) and Simpson diversity (0.257±0.010).