Gut bacteria alleviate irradiation-induced fitness decline via metabolic regulation in Ostrinia furnacalis (Guenée).

The sterile insect technique (SIT) is a green strategy for controlling lepidopteran pests like Ostrinia furnacalis, but its efficacy is limited by irradiation-induced fitness declines in irradiated males. This study investigated the role of gut microbiota in mitigating this damage. Irradiation significantly reduced the diversity and richness of the gut bacterial community in males, altering its structure. Among seven culturable gut isolates, Lactobacillus plantarum and Lactobacillus brevis significantly extended the lifespan of irradiated males, whereas Pseudomonas hibiscicola uniquely enhanced both mating and flight ability. Untargeted metabolomics identified 3591 metabolites and revealed that irradiation severely disrupted core metabolic pathways, including nucleotide metabolism, amino acid biosynthesis, and cofactor biosynthesis. Co-supplementation with L. plantarum and P. hibiscicola effectively restored these metabolic disturbances. In conclusion, specific gut bacteria can repair irradiation-induced fitness defects in male O. Furnacalis by regulating core metabolic pathways. This study provides novel probiotic candidates and a mechanistic basis for enhancing sterile male quality, offering a practical strategy to optimize SIT programs against this pest.