Insecticidal Toxicities and Essential Oil Compositions of Zanthoxylum piperitum and Zanthoxylum schinifolium Fruits in Korea

The compounds in the essential oils extracted from Zanthoxylum schinifolium and Z. piperitum fruits were analyzed by GC-MS and tested to identify acaricidal activities against Dermatophagoides farinae, D. pteronyssinus, and Tyrophagus putrescentiae. The major compounds in Z. schinifolium were found to be estragole (75.03 %), 4-methoxybenzaldehyde (4.60 %), 2-undecanone (2.86 %), nonanal (0.97 %), 2-nonanone (0.80 %), 3-methoxycinnamaldehyde (0.79 %), and α-caryophyllene (0.72 %). In the essential oil of Z. piperitum, the main constituents were shown to be isocarvestrene (28.97 %), geranyl acetate (22.68 %), (+)-citronellal (14.90 %), citronellyl acetate (9.54 %), 4-isopropyl-2-cyclohexenone (5.46 %), myrcene (2.11 %), and citronellol (1.79 %). The Z. schinifolium oil exhibited acaricidal toxicities against D. farinae, D. pteronyssinus, and T. putrescentiae, with LD values of 14.63, 15.36, and 15.67 μg/cm3, respectively, and the LD values of the Z. piperitum oil against three mite species were 4.19, 4.94, and 5.46 μg/cm3, respectively. Based on the LD values, the acaricidal toxicities of the Z. schinifolium oil were circa 2.51, 2.23, and 1.94 times more effective than that of DEET (36.74, 34.25, and 30.43 μg/cm2), respectively. The results show that Z. piperitum and Z. schinifolium oils have the potential to be an alternative material to control mites.