D-Limonene Is the Active Olfactory Attractant in Orange Juice for Bactrocera dorsalis (Insecta: Diptera: Tephritidae)

The oriental fruit fly,Bactrocera dorsalis(Hendel), poses a significant threat to the global fruit industry, causing damage to diverse fruits like citrus, mango, and guava. Chemical pesticides have limited effectiveness, and pesticide residues and pesticide resistance are pressing issues. Therefore, it is essential to develop environmentally friendly pest control methods to address this problem. Behavior-modifying chemicals, including male attractants and intersex protein baits, play a critical role in the control ofB. dorsalis. The mature host fruit serves as both an oviposition site and food source under natural conditions, making it a potential attraction source for oriental fruit flies. Orange,Citrus sinensis, is a main host ofB. dorsalis, and commercial orange juice is a common attractant for the egg laying ofB. dorsalis. Although it can both attract and elicit oviposition behaviors inB. dorsalisadults, its active components are still unclear. This study utilized analytical chemistry, behavioral tests, and electrophysiology to identify the active components of commercial orange juice that attractB. dorsalis, with the aim of providing a reference for the development of behavior-modifying chemical-based techniques to controlB. dorsalis.Five compounds with a high abundance were identified via a GC-MS, including D-Limonene, butanoic acid ethyl ester, β-myrcene, linalool, and α-terpineol. Behavioral and electrophysiological experiments uncovered that D-Limonene was the active substance that was the main attractant in the mixture of these five substances, evoking a strong electrophysiological response in adultB. dorsalis. D-Limonene strongly attracts adultB. dorsalisonly when they are sexually mature, and the attraction is not rhythmic. Olfaction plays a leading role in the attraction of D-Limonene to adultB. dorsalis, andOrco−/−mediates the perception of D-Limonene byB. dorsalis. Overall, D-Limonene is one of the key attractant compounds forB. dorsalisin the volatile compounds of commercial orange juice, offering possible support for the development of behavior-modifying chemical-based technology to controlB. dorsalisin the future.