We evaluated insecticidal and acetylcholine esterase inhibition activity of 11 Apiaceae plant essential oils and their constituents against male and female adults of Blattella germanica. Of 11 Apiaceae plant essential oils tested, dill (Anethum graveolens), carvi (Carum carvi), and cumin (Cuminum cyminum) essential oils demonstrated > 90 % fumigant toxicity against male adults of German cockroach at 5 mg/filter paper. In contact toxicity test, dill (Anethum graveolens), carvi (Carum carvi), cumin (Cuminum cyminum), and ajowan (Trachyspermum ammi) essential oils produced strong insecticidal activity against male and female adults of German cockroach. Among test compounds, carvone, 1,8-cineole, trans-dihydrocarvone, cuminaldehyde, trans-anethole, p-cymene, and γ-terpinene demonstrated strong fumigant toxicity against male and female adults of B. germanica. In a contact toxicity test, carveol, cuminaldehyde, (S)-(+)-carvone, trans-anethole, thymol, and p-cymene showed the strong contact toxicity against B. germanica male and female adults. IC50 values of α-pinene, carvacrol, and dihydrocarvone against female acetylcholine esterase were 0.28, 0.17, and 0.78 mg/mL, respectively. The toxicity of blends of constituents identified in 4 active oils indicated that carvone, cuminaldehyde, and thymol were major contributors to the fumigant or contact toxicity of the artificial blend.

The larvicidal activity of 12 Apiaceae essential oils and their constituents was evaluated against third instar larvae of mosquitoes, Aedes albopictus. Of the 12 Apiaceae essential oils, Dill (Anethum graveolens), Caraway seed (Carum carvi), Cumin (Cuminum cyminum), Carrot seed (Daucus carota), Parsley (Petroselinum sativum) and Ajowan (Trachyspermum ammi) oils at 0.1 mg/ml exhibited 90% larval mortality after 2 days. Analysis by gas chromatography-mass spectrometry led to identification of 8, 3, 13, 12 compounds, respectively. in the oils of Dill (Anethum graveolens), Caraway seed (Carum carvi), Cumin (Cuminum cyminum), Ajowan (Trachyspermum ammi). The compounds thus identified were tested individually for their larvicidal activities against Aedes albopictus. At this same concentration, the individual constituents tested, α-phellandrene, α-Terpinene, ρ -cymene, (+)-Limonene, γ-Terpinene, Thymol, Carvacrol resulted in 100% mortality after 2 days. At this same concentration, the individual constituents tested, (+)-carvone, cuminaldehyde, neral, trans-anethole resulted in 80% mortality after 2 days.

We evaluated insecticidal activity of 11 Apiaceae plant essential oils and their constituents against rice weevil, Sitophilus oryzae.. Of 11 Apiaceae plant essential oils tested, dill (Anethum graveolens), carvi (Carum carvi), caraway seed (Carum carvi) and cumin (Cuminum cyminum) essential oils demonstrated strong fumigant toxicity against adults of rice weevil. Components of 4 active compounds were analyzed by GC and GC-MS, and fumigant toxicity of individual compound was also tested. Among test compounds, carvone, dihydrocarvone, carveol, linalool oxide, neral, cuminaldehyde, and anethole demonstrated the strong insecticidal activity. The toxicity of blends of constituents identified in 4 active oils indicated that carvone, and cuminaldehyde were major contributors to the fumigant toxicity of the artificial blend.

The pinewood nematode, Bursaphelenchus xylophilus is a serious forest pathogen in many countries including Japan, China and Korea. To minimize the environmental problems caused by synthetic chemicals broadly utilized in the control of B. xylophilus, we estimated the nematicidal potency of 97 phytochemicals (49 monoterpenes, 17 phenylpropenes, 16 sesquterpenes and 15 sulfides) against B. xylophilus by measuring their inhibition activity against acetylcholinesterases (ACE, EC 3.1.1.7) of B. xylophilus (BxACEs). In the primary inhibition assay using B. xylophilus crude protein, (+)-α-pinene, (-)-α-pinene and 3-carene in the monoterpenes, ο-anisaldehyde and coniferyl alcohol in the phenylpropenes and cis-nerolidol in the sesquterpenes were observed the > 50% BxACE inhibition rate and they were subsequently estimated the inhibition rate against three recombinant BxACEs. The (+)-α-pinene and coniferyl alcohol showed the high inhibition rate against BxACE-1 and BxACE-2. Interestingly, coniferyl alcohol also exhibited the high inhibition rate against BxACE-3 which would be insensitive to ACE inhibitors.

In this study, we reared box tree pyralid, Glyphodes perspectalis, with artificial diet and identified sex pheromone. Insect F-II and leaf of box tree were used to make artificial diet. Box tree pyralid, Glyphodes perspectalis, is the most serious pest of box tree in Korea, and was recently introduced into Europe. The pheromone components of this moth have been identified as (Z)-11-hexadecenal (Z11-16:Ald), (E)-11-hexadecenal (E11-16:Ald), and (Z)-11-hexadecenol (Z-11- 16:OH) in Japan. In this study, we identified pheromone components of this species by using GC and GC-MS. Three same components, such as (Z)-11- hexadecenal (Z11-16:Ald), (E)-11-hexdecenal (E11-16:Ald), and (Z)-11-hexadecenol (Z-11-16:OH) were also indentified in Korean population, but there was a little difference in ratios. The ratios of these three compounds of Japanese population and Korean population were 5:1.25:1, and 5:0.96:0.2, respectively. The ratios of Z and E-11-hexadecenal were similar, but the ratio of (Z)-11-hexadecenol was lower compared to Japanese population. In field bioassay, (Z)-11-hexadecenal or (E)-11-hexadecenal alone was not attractive to males, but the mixture of Z11-16:Ald and E11-16:Ald was attractive to males. The most effective ratios of Z11-16:Ald and E11-16:Ald was 5:1. Other ratios such as 1:1 and 1:5 (Z:E) was not attractive to males. The attractiveness of Z:11-16:OH will be tested in near future.

In this study, we investigated the nematicidal activities of 102 Korean domestic plant extracts which have not been tested before against B. xylophilus. Nematicidal activity of plant extracts were varied according to plant species and extraction part. Among 102 plant extracts, 42 plant extracts in 22 families showed >50% nematicidal activity against pine wood nematode at 10 mg/mL concentration. Among 31 wood extracts, very strong nematicidal activity (100%) was produced from extract of Neolitsea aciculate, Prunus sargentii and Rhus chinensis at 10 mg/mL concentration. Extracts from Camellia japonica, Carpinus cordata, Daphniphyllum macropodum, Eucommia ulmoides, Ilex cornuta, Myrica rubra, Vaccinium bracteatum, and Zelkova serrata showed strong nematicidal activities (80-99%). The other samples exhibited activities <80%. In a test with leaf extracts, strong neamticidal activity was observed in extract of Machius japonica (100%) followed by Picea koraiensis (99.4%), Meliosma oldhamii (82.7%), and Zelkova serrata (81%). The other 37 plant species revealed <80% mortality. Strong nematicidal activity (>80%) was observed from bark extract of Carpinus cordata, Comus kousa, Cryptomeria japonica, Machius japonica, Quercus glauca and Zelkova serrata. Nematicidal activity of other 19 bark extracts was less than 80%. Twig extract of Smilax china and fruit extract of Forsythia koreana showed 86.6 and 81.4% nematicidal activity at 10 mg/mL concentration, respectively.

Plant essential oils from 26 plant species were tested for their insecticidal activities against the Japanese termite, Reticulitermes speratus Kolbe, using a fumigation bioassay. Responses varied with source, exposure time, and concentration. Among the essential oils tested, strong insecticidal activity was observed with the essential oils of ajowan (Trachyspermum ammi), allspice (Pimenta dioica), caraway (Carum carvi), dill (Anethum graveolens), geranium (Pelargonium graveolens), and litsea (Litsea cubeba). The composition of six essential oils was identified by using gas chromatography-mass spectrometry. The compounds thus identified were tested individually for their insecticidal activities against Japanese termites. Responses varied in a dose-dependent manner for each compound. Phenol compounds exhibited the strongest insecticidal activity among the test compounds further, alcohol and aldehyde groups were more toxic than hydrocarbons. The essential oils and compounds described herein merit further study as potential fumigants for termite control.