Insecticidal and acaricidal activity of carvacrol and β-thujaplicine derived from Thujopsis dolabrata var. hondai sawdust.
Insecticidal and acaricidal components from sawdust of Thujopsis dolabrata var. hondai against eight species of arthropod pests (Reticulitermes speratus, Lasioderma serricorne, Callosobruchus chinensis, Sitophilus oryzae, Plutella xylostella, Myzus persicae, Blattella germanica, and Tetranychus urticae) were isolated by chromatographic techniques and characterized by spectroscopic analyses as the terpenoids carvacrol and β-thujaplicine. In tests using the filter paper diffusion method, carvacrol had broad insecticidal and acaricidal activity against agricultural, stored product, and medical arthropod pests. However, β-thujaplicine showed only weak termiticidal activity. Insecticidal activity of carvacrol was attributable to fumigant action. As a naturally occurring insecticide, carvacrol could be useful as a new preventive agent against damage caused by these arthropod pests.