Screening and Validation of Stable Reference Genes for qRT-PCR Analysis in Epicauta gorhami (Coleoptera: Meloidae)

<i>Epicauta gorhami</i> is a hypermetamorphic insect that mainly forage soybeans during the adult stage. However, the lack of appropriate references hinders our studying of the gene function in <i>E. gorhami</i>. In this study, referring to five computational tools (Ct value, geNorm, NormFinder, BestKeeper and RefFinder), the stability of 10 housekeeping genes (<i>GAPDH</i>, <i>ACT</i>, <i>RPL4</i>, <i>RPL27</i>, <i>α-TUB</i>, <i>RPS18</i>, <i>EF1α</i>, <i>RPS28</i>, <i>RPL13</i> and <i>SOD</i>) was assessed by qRT-PCR under three different conditions (adult ages, tissues/organs and temperatures). The findings suggested that <i>SOD</i> and <i>RPS18</i> were the most ideal references for examine gene transcripts among diverse adult ages and at various temperatures; a pair of <i>RPS18</i> and <i>RPS28</i> was the most reliable genes to assess gene expressions in diverse adult tissues. Finally, the relative expression levels of <i>EgUAP</i> were computed after normalization <i>RPS18</i> and <i>RPS28</i> with across diverse adult tissues. As expected, <i>EgUAP</i> expression was abundant in the foregut, trachea and antenna and scarce in the midgut, hindgut and epidermis. These findings will lay a solid foundation for analyzing the gene expression of <i>E. gorhami</i>.