## 4 Discussion  
Food attractants founded mainly on host volatiles have become a prominent technique for pest trapping [24]. Food volatiles have behavioral influences on both males and females, with females typically being more attracted. This approach offers unique advantages and significant potential in environmentally friendly pest control technology [25; 26]. A single host plant may emit dozens or hundreds of volatiles, but, typically, no more than ten compounds exert a pivotal role. Their composition, proportion, and release level can significantly influence their attractiveness [27; 28; 29; 30]. Therefore, identifying the major components of plant volatiles with behavioral activity is essential for developing food attractants founded on host volatiles. In this study, the volatile components of commercial orange juice were characterized using chemical analysis, and the behavioral activities of the primary responding components were evaluated. Notably, D-Limonene plays a key role in attracting volatile components to both male and female adults. This finding enriched  
Figure 4: Behavioral and electrophysiological responses of olfactory receptor co-receptor mutants to D-Limonene. (**A**) Behavioral response of \(IR8a^{-/-}\) to D-Limonene. (**B**) Behavioral response of mutant \(IR25a^{-/-}\) to D-Limonene. (**C**) Behavioral response of \(Orco^{-/-}\) to D-Limonene. (**D**) Electrophysiological response of D-Limonene to \(IR8a^{-/-}\). (**E**) Electrophysiological response of D-Limonene to \(IR25a^{-/-}\). (**F**) Electrophysiological response of D-Limonene to \(Orco^{-/-}\) (ns: not significant, N = 5, \({}^{*}\)\(p\) < 0.05, ***\(p\) < 0.001, and ***\(p\) < 0.0001). our understanding of the chemical communication between _B. dorsalis_ and its host and provided a solid foundation for improving and developing _B. dorsalis_ food attractants. Limonene is an optically active compound composed of two isomers, R. and S. The R-type isomer, D-Limonene, is the primary isomer [31]. Under natural conditions, D-Limonene is widely distributed in the volatile compounds of the fruits and juices of citrus plants, including oranges, lemons, and graprefruits [32; 33; 34; 35]. D-Limonene is a natural product with a limited toxicity to mammals and a high toxicity to beetles and bed bugs. It can be used as a flavoring agent in soaps, perfumes, foods, and some beverages. Additionally, it can be an alternative to synthetic pesticides [36; 37; 38]. Furthermore, D-Limonene could be a potential behavior-modifying chemical for insects. For instance, it could attract the female potato tuber moth _Pththorimaea operuclella_[39]. In this study, D-Limonene was a potent lure for adult _B. dorsalis_, playing a significant role among five orange juice volatiles. Aside from attraction, commercial orange juice can also induce female insects to lay eggs. However, D-Limonene was found to be ineffective in inducing this behavior. Therefore, the active components responsible for oviposition need to be further characterized in the future to develop more effective behavior-modifying chemicals that function on _B. dorsalis_. Since only chemicals with a high abundance were considered in this study, other chemicals with a high content but a low intensity or low content but strong behavioral responses may have been overlooked. These compounds could be further evaluated using gas chromatography-electroantennographic detection (GC-EAD) to find oviposition attractants or other behavior-modifying compounds. As a polyphagous insect, _B. dorsalis_ is attracted to the volatiles of various host species [19; 40; 41; 42; 43; 44], including linalool and ethyl acetate [45; 46]. Therefore, the behavior-modifying compounds from different host sources can be combined with a suitable ratio to enhance the attraction of _B. dorsalis_ in the future. Inects have evolved a highly specialized and sensitive olfactory system capable of detecting environmental changes in order to locate food, mates, and oviposition sites and to avoid harmful environmental conditions [28; 47].