Development of a high-efficiency sex pheromone formula to control Euproctis pseudoconspersa

The tea tussock moth (Euproctis pseudoconspersa) is one of the most destructive chewing pests in tea plantations and causes a serious allergic reaction on the skin of tea plantation workers. The sex pheromone components of its Japanese population were first identified as 10,14-dimethylpentadecyl isobutyrate (10Me14Me-15:iBu) and 14-methylpentadecyl isobutyrate (14Me-15:iBu), with a stereogenic center. Only 10Me14Me-15:iBu has been identified in the Chinese E. pseudoconspersa population. However, field tests have shown that 10Me14Me-15:iBu cannot meet the demand of effective pest control in China. To develop a high-efficiency E. pseudoconspersa sex pheromone formula, electroantennogram (EAG) recordings of (S)- and (R)-enantiomers of 10Me14Me-15:iBu and 14Me-15:iBu were obtained in the present study. The results demonstrated that the EAG responses of male antennae to (R)-enantiomers were significantly higher than responses to the (S)-enantiomers, and 14Me-15:iBu also elicited EAG activity. Field tests showed that the catch numbers of male moths by (R)-enantiomers were significantly higher (P<0.05) than those of (S)-enantiomers. Addition of 14Me-15:iBu significantly increased the catch numbers of both the (S)- and (R)-enantiomers. The efficient pheromone formula containing 0.75 mg (R)-10Me14Me-15:iBu and 0.1 mg 14Me-15:iBu showed significantly higher attractiveness than commercial pheromone products. Our study demonstrated that (R)-10Me14Me-15:iBu was the major sex pheromone component of E. pseudoconspersa, and 14Me-15:iBu might be the minor sex pheromone component. Furthermore, a high-efficiency sex pheromone formula for E. pseudoconspersa control was defined in this study.