Vol. 8, Special Issue 8, Part Q (2024)

Abstract: The fall armyworm, Spodoptera frugiperda, is a major agricultural pest. This study, conducted at the Department of Agricultural Entomology, UAS, GKVK, Bengaluru (2021-2022), examined the effects of streptomycin sulphate on gut microbiome diversity and fitness in S. frugiperda. Larvae were reared on natural and artificial diets with varying streptomycin concentrations [0.5 g (2X) to 1.5 g (6X) mg/200 mL, and control (0.25 g (X))]. Results revealed a decrease in bacterial diversity (Four bacteria), particularly at higher antibiotic concentrations (6x), with Firmicutes, especially Enterococcus, becoming dominant (75%). Higher streptomycin levels led to reduced pupal weights (0.127 g at 6X) and a high percentage of deformed adults (93% at 6X). These findings emphasize the crucial role of gut microbiota in insect development and highlight the potential impact of antibiotics on pest fitness, stressing the importance of sustainable pest management strategies.