Targeting Trehalose-Glucose Metabolism to Disrupt Symbiont-Mediated Pyrazine Sex Pheromone Synthesis in Bactrocera dorsalis (Oriental Fruit Fly)

Bactrocera dorsalis is an invasive pest causing severe economic losses. Its reproduction depends on sex pheromone-mediated courtship. We previously found that symbiotic Bacillus in the male rectum produce pyrazine sex pheromones (2,3,5-trimethylpyrazine/2,3,5,6-tetramethylpyrazine, TMP/TTMP) in a glucose-dependent manner, but whether host trehalose-to-glucose conversion regulates this remains unknown. Here, we show that mature males have higher rectal glucose and lower trehalose than females. Trehalase (Treh), which hydrolyzes trehalose to glucose, is enriched in the male gut and rectum, whereas trehalose-6-phosphate synthase (TPS), which catalyzes the reciprocal conversion of glucose to trehalose, is enriched in the male fat body. Inhibiting Treh pharmacologically or via RNAi reduces rectal glucose and sex pheromone levels, impairing mating success. Conversely, TPS knockdown elevates rectal glucose and sex pheromones, enhancing male competitiveness. Thus, host trehalose-glucose homeostasis controls glucose supply to symbiotic bacteria, directly regulating pheromone-mediated mating. Treh and TPS are promising targets for precision pest management.