Regulation of reproduction by juvenile hormone synthase and degradation enzyme in Diaphorina citri.

BACKGROUND Insect juvenile hormone (JH) and its regulation are crucial for their reproduction. Diaphorina citri Kuwayama is a major pest in the citrus industry. However, it remains unclear how the JH synthase-encoding gene (DcJHAMT) and the degradation enzyme-encoding gene (DcJHEH) are involved in regulating JH levels, vitellogenin synthesis and ovarian development. RESULTS This study employed RNA interference (RNAi) to silence DcJHAMT and DcJHEH in female D. citri. After DcJHAMT was silenced, the JH concentration decreased, the expression levels of key vitellogenin genes (Vg and VgR) decreased, and ovarian development slowed. After DcJHEH was silenced, the JH concentration increased, the expression levels of Vg and VgR were upregulated, and ovarian development accelerated. After interfering with DcJHAMT, the expression level of DcJHEH decreased, while after interfering with DcJHEH, the expression level of DcJHAMT increased, which confirms that the DcJHAMT and DcJHEH genes are antagonistic to each other and jointly regulate the dynamic balance of JH. CONCLUSION DcJHAMT and DcJHEH were found to synergistically regulate the JH titer and vitellogenin production of D. citri. These results will contribute to the in-depth study of JH pathway regulation in D. citri and bestow significant data for the development of RNAi green pesticides based on reproductive regulatory genes. © 2025 Society of Chemical Industry.