Carvacrol is a terpene compound with various biological activities. However, few studies have specifically focused on its insecticidal activity and mechanism of carvacrol. The larvae of Lymantria dispar are seriously harmful herbivorous insect. This study measured the antifeedant, growth-inhibitory, and toxic effects of carvacrol on L. dispar larvae. To further clarify the insecticidal mechanism of carvacrol, the effects of carvacrol on detoxifying enzymes, antioxidative enzymes, digestive enzyme activities, and the mRNA expression of the above-mentioned enzyme genes were investigated. The results of the study showed that the median lethal concentration (LC₅₀) and the sublethal concentration (LC₂₀) of carvacrol were 1.120 mg/mL and 0.297 mg/mL, respectively, at 72 h. After LC₂₀ treatment of L. dispar larvae for 72 h, food intake and weight gain were significantly lower compared with the control. Enzyme activity assays showed that carvacrol significantly inhibited the activities of carboxylesterase (CarE), glutathione S-transferase (GST), and acetylcholinesterase (AchE), and the inhibition rate of AchE activity was highest (66.51%). Carvacrol also activated the activities of superoxide dismutase (SOD) and catalase (CAT), while it inhibited the activities of lipase (LIP) and amylase (AMS), and first inhibited and then activated protease. In addition, qRT-PCR tests showed that carvacrol affected the mRNA expression levels of CarE, GST, AchE, SOD, CAT, LIP, AMS, and protease. This study helps to clarify the insecticidal mechanism of carvacrol on L. dispar larvae.

香芹酚是具有各种生物活性的萜烯化合物。但是，很少有研究专门关注其杀虫活性和香芹酚的机理。Lymantria dispar的幼虫是严重有害的草食性昆虫。这项研究测量了香芹酚对Dispar幼虫的拒食，生长抑制和毒性作用。为了进一步阐明香芹酚的杀虫机理，研究了香芹酚对解毒酶，抗氧化酶，消化酶活性以及上述酶基因的mRNA表达的影响。研究结果表明，平均致死浓度（LC ₅₀）和亚致死浓度（LC ₂₀在72小时时，香芹酚的分别为1.120 mg / mL和0.297 mg / mL。LC ₂₀处理L. dispar后幼虫72小时，食物摄入和体重增加均明显低于对照组。酶活性检测结果表明，香芹酚显着抑制羧化酶（CarE），谷胱甘肽S-转移酶（GST）和乙酰胆碱酯酶（AchE）的活性，对AchE活性的抑制率最高（66.51％）。香芹酚还激活了超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性，同时抑制了脂肪酶（LIP）和淀粉酶（AMS）的活性，先抑制然后激活了蛋白酶。此外，qRT-PCR测试表明香芹酚会影响CarE，GST，AchE，SOD，CAT，LIP，AMS和蛋白酶的mRNA表达水平。这项研究有助于阐明香芹酚对L. dispar幼虫的杀虫机理。