| Summary: | The aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (ARNT) belong to the bHLH-PAS (basic Helix–Loop–Helix–Period/ARNT/Single-minded) family of transcription factors, which participate in the sensing and transmitting stimuli of exogenous and endogenous chemical substances, and subsequently activates genes transcription involved in various detoxification and physiological functions. However, they have not been identified in <i>Dendroctonus armandi,</i> and their roles in the detoxification metabolism are unclear. In the present study, <i>AhR</i> and <i>ARNT</i> of <i>D. armandi</i> were characterized. Spatiotemporal expression profiling indicated that <i>DaAhR</i> and <i>DaARNT</i> were highly expressed in the adult and larval stages of <i>D. armandi</i> and mainly expressed in the midgut and Malpighian tubules of adults. Additionally, the expression of <i>DaAhR</i> and <i>DaARNT</i> significantly increased after exposure to (−)-𝛽-pinene, (+)-3-carene, and (±)-limonene. Silencing <i>DaAhR</i> and <i>DaARNT</i> increased the susceptibility of <i>D. armandi</i> to (−)-𝛽-pinene, (+)-3-carene, and (±)-limonene, and the activities of detoxification enzyme were also remarkably reduced. Moreover, <i>DaCYP6DF1</i> and <i>DaGSTs2</i> were significantly down-regulated after injections of <i>dsAhR</i> and <i>dsARNT</i> in the male and female adults, with the expression of <i>DaCYP6DF1</i> decreasing by higher than 70%. The present study revealed that the transcription factors <i>AhR</i> and <i>ARNT</i> of <i>D. armandi</i> were induced by terpenoids and participated in the regulation of <i>DaCYP6DF</i>1 expression, which was associated with <i>D. armandi</i>’s susceptibility to (−)-𝛽-pinene and (±)-limonene. These results may provide a theoretical basis for the integrated control of <i>D. armandi</i> and improve our comprehension of insect toxicology.
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