Volatiles from Momordica charantia L. fruits and leaves attract Zeugodacus cucurbitae (Coquillett).

Abstract

Background: The melon fly, Zeugodacus cucurbitae (Coquillett), is a significant pest of cucurbit crops, and its ovipositing females cause direct damage to fruits. However, existing management strategies primarily target the male population, leaving a critical gap in female-specific control measures. Plant-derived volatiles are environmentally sustainable alternatives for developing behavior-based pest-management tools.

Results: The volatiles of the preferred host plant, bitter gourd (Momordica charantia L.), were characterized qualitatively and semiquantitatively using headspace solid-phase microextraction gas chromatography coupled with mass spectrometry (HS-SPME/GC-MS) under targeted sampling conditions. A total of 48 fruit and 44 leaf volatiles were identified, with 28 compounds common to both tissues. Electroantennography (EAG) screenings revealed dose-dependent female antennal responses to 13 compounds, six of which (terpinen-4-ol, trans-verbenol, α-terpineol, 1-decanal, β-caryophyllene and perillaldehyde) exhibited consistent female-specific attraction in behavioral assays. A synthetic six-component blend (each at 10 μg μL^-1 in a 1:1:1:1:1:1 ratio) demonstrated a significantly stronger attraction than any individual compound did. Further optimization yielded an optimized four-component formulation comprising terpinen-4-ol, perillaldehyde, trans-verbenol and β-caryophyllene (each at 10 μg μL^-1 in a 1:1:1:1 ratio), which effectively attracted both male and female Z. cucurbitae.

Conclusion: This plant-based volatile blend offers a targeted candidate attractant with strong potential for subsequent field development for sustainable management of Z. cucurbitae. The six-component blend exhibited potent female-specific attraction, addressing the current control gap for female melon flies, whereas the optimized four-component formulation achieved effective dual-sex attraction and provided a practical tool for integration into monitoring and mass-trapping programs. © 2026 Society of Chemical Industry.