Medicinal plant extracts from 27 plant species in 20 families were tested for their larvicidal activity against house fly, Musca domestica (L.). Responses varied with plant material and concentration. Among plant species tested, Phryma leptostachya var. asiatica showed 100% larvicidal activity against M. domestica at 10 mg/g concentration. Larvicidal activities of Atractylodes japonica, Saussurea lappa, Asiasarum sieboldi, and Gleditsia japonica var. koraiensis were 89.3, 85.3, 93.3 and 96.6% at 10 mg/g concentration, respectively. Extracts of Prunus persica, Curcuma longa and Paeonia moutan produced moderate activity. Larvicidal activity of other plant extracts was less than 50%. Among test plant species, Phryma leptostachya var. asiatica showed the most potent larvicidal activity. The active constituent of P. leptostachya var. asiatica roots was identified as the leptostachyol acetate by spectroscopic analysis. The LC50valuesofleptostachyolacetateagainstM. domestica larvae was 0.039 mg/g. Naturally occurring medicinal plant extracts and Phryma leptostachya var. asiatica root–derived compounds merit further study as potential house fly larval control agents or lead compounds.

Fumigant and contact toxicities of 11 Myrtaceae plant essential oils and their constituents against adult male and female Blattella germanica were evaluated. Of 11 Myrtaceae plant essential oils, Eucalyptus polybractea, E. smithii, E. radiata, E. dives, E. globulus, and Melaleuca uncinata, showed 100% fumigant toxicity against adult male German cockroaches at a concentration of 7.5 mg/liter air concentration. In contact toxicity tests, E. polybractea, E. smithii, E. radiata, E. dives, E. globulus, M. dissitiflora, and M. uncinata produced strong insecticidal activity against adult male and female German cockroaches. Of the essential oil constituents, terpinolene, α-terpinene, and terpinen-4-ol demonstrated strong fumigant toxicity against adult male and female B. germanica. Eugenol, isoeugenol, methyl eugenol, and terpinen-4-ol showed strong contact toxicity against adult male B. germanica. The toxicity of the constituent blends identified from M. dissitiflora essential oils indicated that terpinen-4-ol were major contributor to the fumigant activity or contact toxicity of the artificial blend. Only isoeugenol exhibited inhibition activity against male acetylcholinesterase. IC50values of isoeugenol were 0.22 mg/mL against male acetylcholinesterase.

We evaluated the larvicidal activity of 20 plant essential oils and components from ajowan (Trachyspermum ammi) and Peru balsam (Myroxylon pereira) oils against Aedes aegypti. Of the 20 plant essential oils, ajowan and Peru balsam oils at 0.1 mg/mL exhibited 100% and 97.5% larval mortality, respectively. At this same concentration, the individual constituents, (+)-camphene, benzoic acid, thymol, carvacrol, benzyl benzonate and benzyl trans-cinnamate caused 100% mortality. The toxicity of blends of constituents identified in 2 active oils indicated that thymol and benzyl benzoate were major contributors to the larvicidal activity of the artificial blend. We also tested the acute toxicity of these 2 active oils and their major constituents against the water flea, Daphnia magna. Peru balsam oil and benzyl trans-cinnamate were the most toxic to D. magna. Two days after the treatment, residues of ajowan and Peru balsalm oils in water were 36.2% and 85.1%, respectively. Less than 50% of benzyl trans-cinnamate and thymol were detected in the water at 2 days after treatment. Our results show that the essential oils of ajowan and Peru balsam and some of their constituents have potential as botanical insecticides against Ae. aegypti mosquito larvae.

The box tree pyralid, Glyphodes perspectalis, was reared on an artificial diet based on dried powder of box tree leaves, Buxus microphylla var. koreana, and INSECTA F-II (Nihon Nosan Co., Ltd) at a ratio of 3:7 (w:w) and analyzed in their developmental characteristics from 1st to 4th generation. The developmental period of larva reared on artificial diet was longer than that of larva reared on host plant. Significant difference in larval period was also observed between 1st and other generation groups. Pupation rate was the highest in 4th generation followed by 3rd, 2nd, 1st and host plant group. Significant difference in pupal period was noted between 1st and 3rd generation group. Emergence rate was the highest in 4th generation group followed by 3rd, host plant, 1st and 2nd generation group. There is a significant difference in male and female size between 1st and 4th generation group. Our result indicated that stable rearing of box tree pyralid through the year is possible by artificial diet, and the best adaptation to artificial diet was achieved at 4th generation.

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 63 aliphatic compounds 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, C6, C9, C10 2E-alkenal C12 alkanoic acid were observed the > 45% BxACE inhibition rate and they were subsequently estimated the inhibition rate against three recombinant BxACEs. Whole compounds showed the high inhibition rate against BxACE-1 and BxACE-2. Interestingly, C6 2E-alkenal and C12 alkanoic acid exhibited the high inhibition rate against BxACE-3 which would be insensitive to ACE inhibitors.

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.

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.