Oak wilt disease caused by Raffaelea quercus-mongolicae was firstly reported at Sungnam city, Gyeonggi province, Korea, in 2004, and spread to several area of Korean peninsula. Raffaelea quercus-monglicae was transferred by ambrosia beetle, Platypus koryoensis, and caused oak wilt disease. Because oak wilt disease is mediated by ambrosia beetle, Platypus koryoensis, control of this disease concentrates on managing the ambrosia beetle population. Until now, several control methods such as felling and fumigation of dead oak trees with metham sodium, sticky-roll trap for catching emerged or attacking beetles, and oak tree logs for attraction of ambrosia beetle have been mainly used to control oak wilt disease in Korea. Although effective, current control methods have many side effects. Felling of oak tree is very difficult and dangerous to workers. To reduce the side effects of conventional control methods, new and safe types of control method for managing the ambrosia beetle populations are essential. In this study, we investigated the number of caught beetles, effect of height and direction of collection bottles by using newly developed mass capturing device for P. koryoensis to evaluate the effectiveness of this device as practical use in field.

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.

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.

Using thirty-one essential oils with different manufactured T-tube olfactometers, attraction and repellent efficacy were proved against ggot-mae-mi, Lycorma delicatula. Among tested essential oils, spearmint was selected to have attraction efficacy (94.1%; P<0.001). Spearmint was also showed attraction efficacy in 10 and 2.5 ul, but did not showed in 1 ul. GC analyzed chemical constituents of spearmint were tested with different concentations (10, 5, 2.5, 1 ul). Carvone were showed activity in 10 and 5 ul, but limonene did not showed the activity. When mixing two compounds were showed activity in 10, 5, 2.5 ul as 78.8, 73.5, and 69.7%, respectively. Lavender was selected to have repellent efficacy (86.7%; P<0.001). Lavender was also showed repellency in 10 and 2.5 ul, but did not showed in 1ul. GC analyzed chemical constituents of lavender were tested with different concentrations, results have the activity linalool and terpinen-4-ol in 10 and 5 ul, but linalyl acetate and caryophyllene oxide did not have the activity. Spearmint and lavender showing attraction and repellency, respectively, were keep in lure during 24 hr for penetration with different concentration(30, 20, 10 ul), and attached to the center of Fly catcher, fly sticky trap. The trap was set in the field that founded frequently the L. delicatula. The number of L. delicatula caught in the traps were counted after 5, 10, and 15 days. In attraction efficacy of 20 ul concentration wㄷre high attracted the insect(P<0.001). 30 ul concentration were also have the high attraction (P<0.01). We are now tested the control efficacy in grapevine orchard using these materials.