Comprehensive Assessment of Candidate Reference Genes for Gene Expression Studies Using RT-qPCR in , a Predominant Parasitoid of .

(Waterston) is a predominant parasitoid of the Asian citrus psyllid (ACP), a destructive citrus pest and vector of huanglongbing (HLB) disease in the fields of southern China. To explore the functioning of target genes in , the screening of specific reference genes is critical for carrying out the reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) under different experimental conditions. However, no reference gene(s) for has yet been reported. Here, we selected seven housekeeping genes of and evaluated their stability under the six conditions (developmental stage, sex, tissue, population, temperature, diet) by using software, which contains four different programs (, Δ, , and ). Pairwise variation was analyzed by software to determine the optimal number of reference genes during the RT-qPCR analysis. The results reveal better reference genes for differing research foci: and for the developmental stage; and for sex, and for different tissues (head, thorax, abdomen); and between two populations; and for different temperatures (5, 15, 25, 35 °C); and and for different feeding diets. Furthermore, when the two optimal and two most inappropriate reference genes were chosen in different temperatures and tissue treatments, respectively, the corresponding expression patterns of (as the reporter gene) differed substantially. Our study provides, for the first time, a more comprehensive list of optimal reference genes from for use in RT-qPCR analysis, which should prove beneficial for subsequent functional investigations of target gene(s) in this natural enemy of ACP.