Acaricidal Components of Medicinal Plant Oils Against Dermatophagoides farinae and Dermatophagoides pteronyssinus

The oils of Acorus gramineus, Cinnamomum sieboldii, Eugenia aromatica, and Inula helenium were tested for their acaricidal activity against Dermatophagoides farinae and D. pteronyssinus. Responses varied according to dose and mite species. As compared to the oils, the oil most toxic to D. farinae and D. pteronyssinus was E. aromatica, followed by C. sieboldii, A. gramineus, and I. helenium. On the basis of <TEX>$LD_{50}$</TEX> values of the oils in A. gramineus, C. sieboldii, and E. aromatica, the compound most toxic against D. farinae and D. pteronyssinus was eugenol congeners (isoeugenol>eugenol>acetyleugenol) followed by benzyl benzoate, salicylaldehyde, safro1, DEET, cinnamyl alcohol, and 3-carene. As a naturally occurring acaricide, these oils and eugenol congeners could be useful as new acaricidal agents against Dermatophagoides spp.