Selection and Validation of Reference Genes for RT-qPCR Normalization in (Diptera: Sciaridae) Under Insecticides Stress

(Diptera: Sciaridae) is the most serious root maggot pest which causes substantial damage to the Chinese chive. Organophosphate (OP) and neonicotinoid insecticides are widely used chemical pesticides and play important roles in controlling . However, a strong selection pressure following repeated pesticide applications has led to the development of resistant populations of this insect. To understand the insecticide resistance mechanism in , gene expression analysis might be required. Appropriate reference gene selection is a critical prerequisite for gene expression studies, as the expression stability of reference genes can be affected by experimental conditions, resulting in biased or erroneous results. The present study shows the expression profile of nine commonly used reference genes [, , , , , , , , and )] was systematically analyzed under insecticide stress. Moreover, we also evaluated their expression stability in other experimental conditions, including developmental stages, sexes, and tissues. Five programs (NormFinder, geNorm, BestKeeper, RefFinder, and Δ) were used to validate the suitability of candidate reference genes. The results revealed that the most appropriate sets of reference genes were and across phoxim; and across chlorpyrifos and chlorfluazuron; α and across imidacloprid; α and α across developmental stages; and across larvae; α and across tissues, and and across sex. These results will facilitate the standardization of RT-qPCR and contribute to further research on gene function under insecticides stress.