Effects of X-Ray Irradiation on the Biological Parameters, Gut Microbiota, and Gene Expression of Bactrocera dorsalis: Implications for the Sterile Insect Technique

The sterile insect technique (SIT), traditionally reliant on gamma irradiation, has been an effective strategy for controlling Bactrocera dorsalis. However, strict regulations governing gamma radiation sources and the limited research on the responses of B. dorsalis to X-ray irradiation have hindered the further development of SIT. This study demonstrated that X-ray dosage, pupal age, and their interaction significantly influenced the emergence parameters of B. dorsalis. Further experiments revealed that irradiating 8-day-old pupae resulted in a significant reduction in flight ability, lifespan, and fecundity in emerging adults. However, optimized doses ranging from 70 to 100 Gy effectively induced complete sterility while exerting minimal adverse effects on male quality. X-ray irradiation induced notable shifts in the gut microbiota composition of B. dorsalis, marked by a reduction in the abundance of Enterobacter, Citrobacter, and Proteus, accompanied by an enrichment of Providencia. Additionally, broad correlations among dominant bacterial genera were observed. Transcriptomic analysis further indicated that irradiation had a profound impact on gene expression in both male and female adults, with 100 and 34 differentially expressed genes (DEGs) identified in females and males, respectively. Gene Ontology (GO) enrichment analysis revealed six enriched GO terms common to both sexes. Correlation analysis suggested potential associations between specific differentially abundant bacterial genera and DEGs. These findings optimize X-ray-based SIT for B. dorsalis and provide new insights into its effects on gut microbiota and gene expression, offering theoretical support for the refinement of SIT strategies.