Commercial essential oils from 29 plant species were tested for their
nematicidal activity against the pine wood nematode, Bursaphelenchus
xylophilus. Good nematicidal activity against B. xylophilus was achieved
with essential oils of Gaultheria fragrantissima and Zanthoxylum alatum.
GC-MS analysis of the corresponding oils led to the identification of two
and ten major compounds, respectively. Four compounds, methyl salicylate,
ethyl salicylate, methyl trans-cinnamate and ethyl trans-cinnamate, were
tested individually for their nematicidal activities against the pine wood
nematode. Methyl and ethyl salicylates showed strong nematicidal activity at
concentration of 2.0 mg ml–1. Concentrations of 1.0 mg ml–1, as well as
lower concentrations showed only minor effects. Another compound, methyl
trans-cinnamate, showed 100% activity at concentrations of 0.0625-2.0 mg
ml–1. With ethyl trans-cinnamate, 100% mortality was observed at
concentrations of 0.25-2.0 mg ml–1. The essential oils and their components
described herein merit further study as potential nematicides against the
pine wood nematode.