Wu_2023_Plants.(Basel)_12_

In this study, we analyzed the components of Mentha spp. essential oils (EOs) and evaluated their major constituents and binary combinations against Reticulitermes dabieshanensis. We also determined the activities of esterases (ESTs), glutathione S-transferases (GSTs), and acetylcholinesterase activity (AChE) in treated insects. According to our findings, the most effective oils were those obtained from M. citrata (with the major constituent linalool constituting 45.1%), M. piperita (menthol, 49.1%), and M. spicata (carvone, 69.0%), with LC(50) values of 0.176, 0.366, and 0.146 microL/L, respectively. The LC(50) values were recorded for linalool (0.303 microL/L), followed by menthol (0.272 microL/L), and carvone (0.147 microL/L). The insecticidal potency increased with binary mixtures of major active constituents, with carvone strongly synergizing the toxicity of linalool and menthol against R. dabieshanensis. Compared to the control, except for M. citrata treated with no difference in alpha-NA or GST activity, the activities of ESTs and GST in other treatment groups were significantly increased. Additionally, our results found that Mentha spp. EOs and their major constituents inhibited the activity of AChE in vivo and in vitro. Finally, we performed a structure-based virtual screening of linalool, menthol, and carvone to identify that linalool had the greatest potential to bind to the active site of AChE. The present study suggests that Mentha spp. EOs could provide an additional approach for the management of termites over synthetic insecticides.