Floral Volatile Organic Compound Profiles of Eco-Functional Plants Shape Plant–Insect Interactions and Their Community Structures in Wheat Agroecosystems

Elucidating volatile-mediated chemical communication between functional plants and natural enemies is critical for sustainable pest management. Three functional plants (<i>Cnidium monnieri</i> (L.) Cusson, <i>Angelica sinensis</i> (Oliv.) Diels, and <i>Ligustrum quihoui</i> Carriere) were established around wheat fields to investigate natural enemy recruitment over two years (2024-2025). Functional plants established differential insect community structures with distinct taxonomic profiles. GC-MS analysis revealed species-specific volatile organic compound (VOC) profiles, with phenol, nonanal, α-pinene, and α-farnesene highly emitted. Y-tube olfactometer bioassays demonstrated differential attractive responses of three natural enemy species to plant VOC. Synthetic VOC bioassays with seven key compounds (α-farnesene, phenol, copaene, α-pinene, caryophyllene, d-limonene, and linalool) revealed species-specific, concentration-dependent attraction and repellent responses. Electroantennogram recordings confirmed that natural enemies detected VOCs with differential sensitivity patterns, revealing distinct neurophysiological mechanisms underlying behavioral preferences. Strategic functional plant deployment enables predictable natural enemy recruitment through species-specific VOC signaling for integrated pest management.