*3.7. qRT-PCR*

We further used qRT-PCR to validate the expression levels of three randomly selected transcripts in the parasitoid wasps. The primers for the three transcripts and internal control (actin) were predicted using Prime3 and can be accessed in Table 4. We used Log2FC and RNE to show the expression changes of the transcripts in C, M, and G identified by RNA-Seq and qRT-PCR, respectively. Overall, the expression patterns of these transcripts in most comparisons were consistent by both RNA-Seq and qRT-PCR except three (TRINITY\_DN1020\_c0\_g1\_i3, TRINITY\_DN500\_c0\_g1\_i2 in C\_vs\_M, and TRINITY\_DN1020\_c0\_g1\_i3 in M\_vs\_G). The high agreemen<sup>t</sup> of the gene expression patterns in RNA-Seq and qRT-PCR indicates that the transcripts identified in this study might be functionally expressed in the parasitoid wasps maintained with fruit flies with different scents, which requires future functional experiments.


**Table 4.** qRT-PCR validation. Log2 FC represents the log2 values of the fold change of a transcript identified by the RNA-Seq while RNE represents the relative normalized expression of a transcript identified by qRT-PCR.
