Abstract
<title>Abstract</title> <p> Background The black soldier fly (BSF, <italic>Hermetia illucens</italic> ) is transforming the global bioeconomic through green insect-based animal feed, and as source of biomaterials. However, large-scale production is often constrained by low mating success and a poor understanding of adult sexual chemical cues. Here, we investigated the role of endogenous semiochemicals in modulating mating behavior and reproductive output. Results Gas chromatography–mass spectrometry (GC-MS) analysis revealed distinct volatile profiles across sexes and mating statuses indicating chemically mediated sexual differentiation. We found terpene enriched volatiles, including sesquiterpene isomers α-cedrene and β-cedrene. In single-pair mating assays, out of 12 compounds in eight doses tested α-cedrene (3.0 µg/mL) yielded the highest mating success, corresponding to a 7.4-fold mating versus the control, however, β-cedrene elicited no comparable response. α-cedrene not only increase mating success, but also significantly reduced courtship latency by 43.3% and extended mating duration by 20.4% compared to the control group. Furthermore, perfuming the rearing cage with α-cedrene significantly amplified both fecundity and fertility, manifested as a 2.1-fold increase in total egg mass and a 3.6-fold increase in larval yield compared to controls demonstrating substantial gains in fecundity and fertility. These collective results position α-cedrene (3.0 µg/mL) as a potent aphrodisiac compound for the augmentation of BSF’s reproductive efficiency. Electroantennography, data showed α-cedrene elicited a dose-dependent antennal depolarization consistent with sensory adaptation but not β-cedrene. Conclusion Our finding demonstrates how stereochemical divergence differentially regulates reproductive behavior through olfactory pathways and provide a mechanistic foundation for optimization of insect mass-rearing systems to enhance fecundity and fertility. </p>