Identification of kairomonal compounds from host plants attractive to melon fly, Zeugodacus cucurbitae (Coquillett) (Diptera:Tephritidae)

Abstract

Background and Objective: Melon fly, Zeugodacus cucurbitae (Coquillett) (Diptera:Tephritidae), is a major agricultural pest in Indonesia. It is considered a specialist insect since it only attacks plants that belong to the family Cucurbitaceae. Such insects commonly use plant semiochemicals to find appropriate hosts for feeding and oviposition. The objective of this study was to identify chemical compounds from the host plants that were attractive to male and female Zeugodacus cucurbitae (Z. cucurbitae). Materials and Methods: Chemical blends were extracted from the host plants and responses of the melon fly to the scents were studied by Y-olfactometer. Results: Fractions of bitter gourd (Momordica charantia) were more attractive to male and female Z. cucurbitae compared to those of angled luffa and cucumbers. Compounds extracted from the leaves of bitter gourd after saponification were identified as a ketone (6,10,14-trimethyl-2-pentadecanon), an aldehyde (3,7,11,15-tetramethyl-2-hexadecen-1-ol) and phytosterol. Conclusion: The ketones and the aldehydes are kairomones for Z. cucurbitae.