Three antimicrobials alter gut microbial communities and causing different mortality of brown planthopper, Nilaparvata lugens Stål

The symbionts in the gut of brown planthopper play an important role in the nutrition utilization and growth of their host, Nilaparvata lugens Stål (Hemiptera: Delphacidae). Controlling the BPH infection on rice by inhibiting the symbionts using antimicrobials is feasible. However, the impact of antimicrobials on the microbiome in the gut has not been fully elucidated. In this study, we found the mortality reached 35.5%, 33.1% and 19.4%, when BPHs were exposed to toyocamycin, tebuconazole, and zhongshengmycin, respectively. Significant differences were found between the structures of gut microbial communities in adult BPHs treated with different antimicrobials and water. The antimicrobials reduced the fungal diversity by reducing the non-dominant fungi abundance, and increased bacterial diversity by inhibiting the dominant bacteria Acinetobacter in the gut. The diversification of taxonomic groups in gut depended on the different selective stress of antimicrobials. For the microbial absolute abundance, the total microbial gut community abundance decreased under antimicrobial exposure, but the absolute abundance of Serratia significantly increased in the antimicrobial treatment group. Overall, our study enriched the knowledge of microbiomes in the gut of BPH under the antimicrobial treatment and provided guidelines to enhance the pest management effect of BPH by using antimicrobials.