## 2 Materials and Methods
### Olfactory Trap Assay  
Commercial orange juice was employed as an attractant to evaluate whether its volatiles were appealing to adult _B. dorsalis_. According to the response results of the chemical substances in the GC-MS identification, the classes of chemical substances with a high abundance were selected, and the ratio of the compound mixtures (1000 \(\mu\)L) was determined based on the ratio of the chromatographic peak areas (the quantitative external standard method, see Section 2.3). A total of three mixtures was generated, with each mixture removing the compound with the highest abundance to assess the crucial role of this compound in the complex. The active compounds isolated from these experiments were individually tested to characterize their attractiveness on adult _B. dorsalis_ across different ages and during varying time periods. Ultra-pure water was employed as the control when assessing the attractiveness of the orange juice. Paraffin oil was used as the control when testing the attractiveness of individual or combined chemicals.  
The experiment was performed in insect cages measuring 18 cm \(\times\) 24 cm \(\times\) 14 cm. Initially, 30 male insects, aged 12 days, were placed into the cage. The trap consisted of a clear conical flask with a top diameter of 3 cm, a base diameter of 5 cm, and a height of 7.5 cm. An entry point for the adult insects was created using the tip of a 1 mL pipette attached to the flask. Once the adult insects entered the trap, they were unable to escape. Subsequently, two traps were introduced: one containing the attractant (the experimental group) and the other containing paraffin oil (the control group). The two trap bottles were positioned approximately 8-10 cm apart. The cage was positioned under a 50 lux light source for the duration of the experiment. Upon completion, the number of males in each trap was documented. Each experiment was repeated five times following this protocol. The experiment was performed at 26 \(\pm\) 1 \({}^{\circ}\)C from 17:00 to 9:00 the following day. When testing D-Limonene at different ages, the experimental insects were 3 days old, 6 days old, 9 days old, and 12 days old. Adults aged 12 days old were selected to test the attractiveness of D-Limonene at different time periods (9:00-17:00 and 17:00 to 9:00 the following day). The olfactory co-receptor mutants _Oroo_-/-, _IR8a_-/-, and _IR25a_-/- were employed to identify the candidate receptors for detecting D-Limonene. Following the experiment, the number of adult flies entering the trap was documented, and the trapping rate was calculated as follows: Attractant rate = (Number of adults in the trap/total number of experimental adults) \(\times\) 100%.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Compound Name** & **CAS** & **Brand Name** & **State** \\ \hline butanoic acid ethyl ester & 105-54-4 & Macklin & liquid \\ D-Limonene & 5989-27-5 & Macklin & liquid \\ linalool & 78-70-6 & Sigma-Aldrich & liquid \\ \(\alpha\)-terpineol & 98-55-5 & Sigma-AldrichMAC & crystal \\ \(\beta\)-myrpene & 123-35-3 & aladdin & liquid \\ n-hexane & 110-54-3 & Sigma-Aldrich & liquid \\ paraffin oil & 8012-95-1 & Sigma-Aldrich & liquid \\ \(\alpha\)-Pinene & 80-56-8 & Macklin & liquid \\
3-Carene & 13466-78-9 & Macklin & liquid \\ Terpinen-4-ol & 562-74-3 & Macklin & liquid \\ (-)-Carvone & 6485-40-1 & Macklin & liquid \\ \(\gamma\)-Terpinene & 99-85-4 & Macklin & liquid \\ \(\beta\)-Coime & 13877-91-3 & Macklin & liquid \\ Cyclohexene, 1-methyl-4-(1- & 586-62-9 & Macklin & liquid \\ methylethylene)- & & \\ \hline \end{tabular}
\end{table}
Table 1: Compound information required for the experiment.