EGFR Is Essential for Ovary but Not Testis Development in the Parasitoid Wasp Leptopilina drosophilae

The epidermal growth factor receptor (EGFR) signaling pathway is an important regulator of insect reproduction, yet its function in parasitoid wasps remains largely unknown. Here, we investigated the role of EGFR in the reproductive development of the parasitoid wasp Leptopilina drosophilae, an effective natural enemy of the globally invasive pest Drosophila suzukii. We cloned the LdEGFR gene and confirmed its structural conservation through phylogenetic analysis. Using RNA interference (RNAi), we demonstrated that LdEGFR is essential for ovarian development but dispensable for testis development. Intriguingly, this sexually dimorphic functional requirement contrasts with its expression pattern, as LdEGFR transcript levels were approximately 171-fold higher in testes than in ovaries. Transcriptomic analysis of ovaries following LdEGFR knockdown revealed significant down-regulation of genes involved in transporter, DNA replication, cell cycle, and oocyte meiosis pathways, providing a molecular basis for the observed ovarian defects. Our findings establish LdEGFR as a critical regulator of female reproduction in L. drosophilae and highlight a notable decoupling between transcript abundance and functional essentiality. This study not only advances the understanding of reproductive regulation in parasitoid wasps but also identifies LdEGFR as a potential target for enhancing the mass rearing of this promising biocontrol agent.