Comparison of electrophysiological and behavioral responses of tephritid (Diptera: Tephritidae) pests to cucurbit host odors

Abstract

Developing species-specific lures for female tephritid fruit flies is crucial for sustainable pest management, yet remains a significant challenge. This study aimed to identify potential attractants for Zeugodacus cucurbitae, a major pest on cucurbit crops, by comparing the olfactory responses of females to host plant volatiles with those of two related fruit-infesting species, Bactrocera dorsalis and Ceratitis capitata. Using gas chromatography coupled electroantennogram detection (GC-EAD) and GC-mass spectrometry (GC–MS), we identified 28 antenna-active compounds from flowers and fruits of Cucumis sativus L., Cucurbita pepo L., and Cucurbita mixta L. While eight compounds elicited responses in all three tephritid species, indicating shared olfactory sensitivity, B. dorsalis and C. capitata detected a broader range of volatiles than Z. cucurbitae. Behavioral assays in a six-choice olfactometer demonstrated that synthetic blends based on cucurbit host odors attracted females of all three species. These findings suggest that, while there is some overlap in host odor perception, subtle differences exist that could be exploited for species-specific lure development. Further optimization and field testing of these promising blends are recommended to enhance targeted pest management strategies for Z. cucurbitae.