• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.350-356
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• 2011

Environment-friendly agro-materials tend to be preferred to chemical insecticides recently. For this reason, many studies were conducted to develop environment-friendly insecticides containing natural materials. The purpose of this study was to assess ecotoxicity for 5 plant essential oils (Thyme white, Clove bud, Cassia, Lavender, Lemon eucalyptus) expected to prevent from pests and be used for agro-materials. Target species used to assess acute toxicity were aquatic invertebrate (Daphina magna), fish (Oryzias latipes), honeybee (Apis mellifera L.) and earthworm (Eisenia fetida). The EC50 value, toxicological responses of thyme white, clove bud, and cassia to Daphina magna were 2.5, 2.8, and $6.9mg\;L^{-1}$ respectively and these values were moderately toxic according to standard of USEPA. $EC_{50}$ of Lavender and lemon eucalyptus were >$10mg\;L^{-1}$ then they were considered as slightly toxicity. In case of acute toxicity test to fish, $LC_{50}$ of thyme white and cassia were 6.7 and $7.5mg\;L^{-1}$ each other. The other plant essential oils indicated $LC_{50}$ >$10mg\;L^{-1}$. Acute contact and oral toxicity test to Honeybee were conducted. As a result, $LD_{50}$ of all essential oils were >$100{\mu}g$ a.i. $bee^{-1}$ in both of tests. In case of acute toxicity test to earthworm, $LC_{50}$ of thyme white, clove bud, cassia, lavender, and lemon eucalyptus were 149, 230, 743, 234, and $635mg\;kg^{-1}$, respectively. In conclusion, if the safety for earthworm is confirmed, 5 plant essential oils are expected to be use for environment-friendly insecticide materials with low risk against ecosystem and contribute to developing environment-friendly agro-materials.