Identification of the Female-Produced Sex Pheromone of the Dotted White Geometrid Naxa seriaria (Lepidoptera: Geometridae).

The dotted white geometrid moth, Naxa seriaria Motschulsky (Lepidoptera: Geometridae), is a pest of Oleaceae in Korea, Japan, and China. In this study, we identified (3Z,6Z,9Z,12Z,15Z)-heneicosapentaene (C-21 pentaene) as the only compound in extracts of the pheromone glands of female N. seriaria causing a response from receptors on the antennae of males in analyses by gas chromatography with electroantennographic detection. The synthetic sex pheromone elicited dose-dependent electrophysiological responses from antennae of male N. seriaria. In field tests, more male moths were captured in traps baited with synthetic C-21 pentaene than in unbaited traps, and increasing the loading of C-21 pentaene in the lure increased catches of male moths. Significantly more male N. seriaria moths were caught in delta traps than in bucket traps. Based on these results, C-21 pentaene is proposed to be the major, if not the only, component of the sex pheromone of N. seriaria.

Reactive oxygen species mediated-antifungal activity of cinnamon bark (Cinnamomum verum) and lemongrass (Cymbopogon citratus) essential oils and their constituents against two phytopathogenic fungi.

To find new and safe type of control agents against phytopathogenic fungi, the fumigant antifungal activity of 10 plant essential oils and constituents identified in cinnamon bark (Cinnamomum verum) and lemongrass (Cymbopogon citratus) essential oils was investigated against two phytopathogenic fungi, Raffaelea quercus-mongolicae and Rhizoctonia solani. Among plant essential oils, cinnamon bark and lemongrass essential oils showed 100% inhibition of R. quercus-mongolicae and R. solani at 5 mg/paper disc, respectively. Among test constituents, salicylaldehyde, eugenol, and hydrocinnamaldehyde showed 100% inhibition of growth of R. quercus-mongolicae at 2.5 mg/paper disc. Neral, geraniol, geranial, trans-cinnamaldehyde, methyl cinnamate, isoeugenol, and methyl eugenol exhibited >80% inhibition of growth of R. quercus-mongolicae at 2.5 mg/paper disc. Neral, geranial, trans-cinnamaldehyde, hydrocinnamaldehyde, and salicylaldehyde showed 100% inhibition of growth of R. solani at 2.5 mg/paper disc. A fumigant antifungal bioassay of artificial blends of the constituents identified in cinnamon bark and lemongrass essential oils indicated that trans-cinnamaldehyde and geranial were major contributors to the fumigant antifungal activity of the artificial blend. Confocal laser scanning microscopy images of fungi treated with cinnamon bark and lemongrass essential oils, trans-cinnamaldehyde, neral, and geranial revealed the reactive oxygen species (ROS) generation and cell membrane disruption.

Antibacterial mode of action of trans-cinnamaldehyde derived from cinnamon bark (Cinnamomum verum) essential oil against Agrobacterium tumefaciens.

The fumigant antibacterial activities of 50 plant essential oils belonging to 10 families were investigated against Agrobacterium tumefaciens. Among the test plant essential oils, Cinnamomum verum (cinnamon bark) essential oil showed the most potent fumigant antibacterial activity. When we investigated the antibacterial activities of compounds identified from cinnamon bark essential oil and 9 congeners of trans-cinnamaldehyde, lengths of inhibition zone of trans-cinnamaldehyde, salicylaldehyde and hydrocinnamaldehyde were 1.28, 1.73, and 1.24 cm at 0.625 mg/paper disc concentration, respectively. To determine the mode of action of trans-cinnamaldehyde and salicylaldehyde, intercellular reactive oxygen species (ROS) generation and cell membrane integrity were determined using a confocal laser scanning microscopy. Furthermore, we compared the up- and down-regulated gene expression of A. tumefaciens treated with trans-cinnamaldehyde and salicylaldehyde with that of untreated A. tumefaciens. With cutoffs of |log2FC| > 1 and FDR < 0.05, 29 and 43 down-regulated genes and 27 and 117 up-regulated genes were found in the treatment of trans-cinnamaldehyde and salicylaldehyde, respectively. Based on the ROS generation results, cell membrane integrity assay, and gene expression, we conclude that the antibacterial mode of action of trans-cinnamaldehyde and salicylaldehyde is ROS generation by the Fenton reaction caused by the down-regulation of an ATP synthesis-related gene cluster, corrupted iron ion homeostasis, and a corrupted ROS defense mechanism. The high concentration of ROS damaged the A. tumefaciens cell membrane, which caused cell death.

Plant-derived compounds regulate formation of the insect juvenile hormone receptor complex.

Insect growth regulators (IGRs) are attractive pest control agents due to their high target specificity and relative safety to the environment. Recently, plants have been shown to synthesize IGRs that affect the insect juvenile hormone (JH) as a part of their defense mechanisms. Using a yeast two-hybrid system transformed with the Aedes aegypti JH receptor as a reporter system, we identified several JH agonists (JHAs) and antagonists (JHANs) causing retardation in the ovarian development of female Asian tiger mosquito, Aedes albopictus, from plant essential oil compounds. While the JHAs increased the expression of a JH-induced gene, the JHANs caused a reduction in the expression of the same gene. The compounds identified in this study could provide insights into plant-insect interactions and may be useful for the development of novel IGR insecticides.

Identification of the Aggregation-sex Pheromone Produced by Male Monochamus saltuarius, a Major Insect Vector of the Pine Wood Nematode.

In this study, we isolated and identified an aggregation-sex pheromone from Monochamus saltuarius, the major insect vector of the pine wood nematode in Korea. Adult males of M. saltuarius produce 2-undecyloxy-1-ethanol, which is known as an aggregation-sex pheromone in other Monochamus species. We performed field experiments to determine the attractiveness of the pheromone and other synergists. More M. saltuarius adult beetles were attracted to traps baited with the pheromone than to unbaited traps. Ethanol and (-)-α-pinene interacted synergistically with the pheromone. Traps baited with the pheromone + (-)-α-pinene +ethanol were more attractive to M. saltuarius adults than traps baited with the pheromone, (-)-α-pinene, or ethanol alone. Ipsenol, ipsdienol, and limonene were also identified as synergists of the aggregation-sex pheromone for M. saltuarius adults. In field experiments, the proportion of females was much higher in the beetles caught in traps than among the beetles emerging from naturally-infested logs in the laboratory. Our results suggest that a combination of aggregation-sex pheromone and synergists could be very effective for monitoring and managing M. saltuarius.

Nematicidal Activity of 3-Acyltetramic Acid Analogues Against Pine Wood Nematode, Bursaphelenchus xylophilus.

Among 98 3-acyltetramic acid analogues, compounds 1c, 2c, 2f and 2g, showed >90% nematicidal activity against the pine wood nematode Bursaphelenchus xylophilus at a 10 µg/mL concentration. The nematicidal activities of compounds 1d, 1h, and 2k were a little lower at 88.0%, 85.8%, and 57.2% at a 10 µg/mL concentration, respectively. The nematicidal activity of emamection benzoate, widely used in Korea for the prevention of pine wilt disease, was 32.3% at a 10 µg/mL concentration. Other 3-acyltetramic acid analogues showed less than 30% nematicidal activity. A structure-activity relationship study indicated that the chain length of the C-acyl substituent was very important for high nematicidal activity. All active compounds had C13H27 or C11H23 acyl substituents, in two closely related groups with the common physicochemical properties of a polar surface area 57.6A², PSA (polar surface area) 7.8-8.6% and ClogP (calculated partition coefficient) 5.1-5.9 and a polar surface area 75-84A², PSA 11.1-11.6% and ClogP 4.7-5.1, respectively. Our study indicates that active 3-acyltetramic acid analogues could have potential as lead compounds for developing novel pine wood nematode control agents.

Larvicidal and Nematicidal Activities of 3-Acylbarbituric Acid Analogues against Asian Tiger Mosquito, Aedes albopictus, and Pine Wood Nematode, Bursaphelenchus xylophilus.

Widespread concern for the occurrence of resistant strains, along with the avoidance of the use of highly toxic insecticides and their wide environmental dispersal, highlights the need for the development of new and safer pest control agents. Natural products provide inspiration for new chemical entities with biological activities, and their analogues are good lead compounds for the development of new pest control agents. For this purpose, we evaluated the larvicidal and nematicidal activities of 48 3-acylbarbituric acid analogues against the Asian tiger mosquito, Aedes albopictus and the pine wood nematode, Bursaphelenchus xylophilus, organisms of increasing global concern. Among the 48 3-acylbarbituric acid analogues, four compounds-10, 14d, 14g and 19b-showed >90% larvicidal activity against Ae. albopictus at 10 µg/mL concentration, and one (compound 10) showed the strongest larvicidal activity against Ae. albopictus, with a LC50 value of 0.22 µg/mL. Only compound 18 showed strong nematicidal activity against pine wood nematode. Most active compounds possessed similar physicochemical properties; thus, actives typically had ClogP values of around 1.40-1.50 and rel-PSA values of 16-17% and these similar cheminformatic characteristics reflect their similar structure. This study indicates that active 3-acylbarbituric acids analogues have potential as lead compounds for developing novel mosquito control agents.

Fumigant Toxicity of Lamiaceae Plant Essential Oils and Blends of Their Constituents against Adult Rice Weevil Sitophilus oryzae.

To find a new and safe alternative to conventional insecticides, we evaluated the fumigant toxicity of eight Lamiaceae essential oils and their constituents against the adult rice weevil Sitophilus oryzae. Of the eight species tested, hyssop (Hyssopus offcinalis), majoram (Origanum majorana), and Thymus zygis essential oils showed strong fumigant toxicity against S. oryzae adults at 25 mg/L air concentration. Constituents of active essential oils were analyzed by gas chromatography coupled to flame ionization detector (FID) and gas chromatography-mass spectrometry. A total of 13, 15, and 17 compounds were identified from hyssop, majoram, and Thymus zygis essential oils, respectively. Pinocamphone and isopinocamphone were isolated by open column chromatography. Among the test compounds, pinocamphone and isopinocamphone showed the strongest fumigant toxicity against S. oryzae. Sabinene hydrate, linalool, α-terpineol, and terpinen-4-ol exhibited 100% fumigant toxicity against S. oryzae at 3.9 mg/L air concentration. The measured toxicity of the artificial blends of the constituents identified in hyssop, majoram, and Thymus zygis oils indicated that isopinocamphone, terpine-4-ol, and linalool were major contributors to the fumigant toxicity of the artificial blend, respectively.

Fumigant toxicity and acetylcholinesterase inhibitory activity of 4 Asteraceae plant essential oils and their constituents against Japanese termite (Reticulitermes speratus Kolbe).

This study investigated the fumigant toxicity of 4 Asteraceae plant essential oils and their constituents against the Japanese termite Reticulitermes speratus Kolbe. Fumigant toxicity varied with plant essential oils or constituents, exposure time, and concentration. Among the tested essential oils, those from Chamaemelum nobile exhibited the strongest fumigant toxicity, followed by those from Santolina chamaecyparissus, Ormenis multicaulis, and Eriocephalus punctulatus at 2 days after treatment. In all, 15, 24, 19, and 9 compounds were identified in the essential oils from C. nobile, E. punctulatus, O. multicaulis, and S. chamaecyparissus, respectively, by using gas chromatography, gas chromatography-mass spectrometry, or open-column chromatography. The identified compounds were tested individually for their fumigant toxicity against Japanese termites. Among the test compounds, trans-pinocarveol, caryophyllene oxide, sabinene hydrate, and santolina alcohol showed strong fumigant toxicity against Japanese termites. Acetylcholinesterase (AChE) inhibition activity of the identified compounds from C. nobile, E. punctulatus, O. multicaulis, and S. chamaecyparissus essential oils were tested to determine the mode of their action. The IC50 values of (+)-α-pinene, (-)-limonene, (-)-α-pinene, ß-pinene, and ß-phellandrene against Japanese termite AChE were 0.03, 0.13, 0.41, 0.42, and 0.67mg/mL, respectively. Further studies are warranted to determine the potential of these essential oils and their constituents as fumigants for termite control.

Fumigant toxicity of Oriental sweetgum (Liquidambar orientalis) and valerian (Valeriana wallichii) essential oils and their components, including their acetylcholinesterase inhibitory activity, against Japanese termites (Reticulitermes speratus).

This study investigated the fumigant toxicity of oriental sweetgum (Liquidambar orientalis) and valerian (Valeriana wallichii) essential oils and their components against the Japanese termite (Reticulitermes speratus). The fumigant toxicity of oriental sweetgum and valerian oil differed significantly according to exposure time. Oriental sweetgum showed toxicity at short exposure times (2 days), and the toxicity of valerian oil was high 7 days after treatment. The main constituents of oriental sweetgum and valerian oils were tested individually for their fumigant toxicity against Japanese termites. Among the test compounds, benzyl alcohol, acetophenone, 1-phenyl-1-ethanol, hydrocinnamyl alcohol, trans-cinnamyl aldehyde, trans-cinnamyl alcohol, cis-asarone, styrene, and cis-ocimene showed toxicity against Japanese termites 7 days after treatment. Hydrocinnamyl alcohol and trans-cinnamyl alcohol were found to be the major contributors to the fumigant antitermitic toxicity of oriental sweetgum oil. The acetylcholinesterase (AChE) inhibition activity of two oils and their constituents was tested to determine their mode of action. Only cis-ocimene showed strong AChE inhibition activity with an IC50 value of 0.131 mg/mL. Further studies are warranted to determine the potential of these essential oils and their constituents as fumigants for termite control.

Morphological and biological characteristics of Eriborus sp. (Hymenoptera: Ichneumonidae), a parasitoid wasp of Cydalima perspectalis (Lepidoptera: Crambidae).

The box tree moth (BTM), Cydalima perspectalis Walker, is a pest that infests various plants within the Buxus genus. Although a specific parasitoid wasp species associated with the BTM has been observed in the Republic of Korea, no research on this species has been published. Here, we describe the fundamental morphological and biological characteristics of this parasitoid. We have identified the wasp as belonging to the genus Eriborus (Hymenoptera: Ichneumonidae: Campopleginae). Eriborus sp. parasitizes within the living host body, with 1 wasp emerging from each host. The parasitism rate observed in collected BTM populations was 33.1%. The emergence rate was 87.1%, with all emerging adults being females, resulting in a sex ratio of 0. The pupal period avg 9.5 days, and the adult lifespan avg 10.5 days. Eriborus sp. parasitized BTM larvae from the first to the fourth instar and reproduced by thelytokous parthenogenesis. Eriborus sp. exhibited morphological differences compared with previously reported Eriborus species in Korea, particularly in the length of the ovipositor sheath. Additionally, the proportion of the highest similarity in nucleotide sequences of mitochondrial cytochrome oxidase I DNA was only 94.53%, rendering species identification using GenBank's mt cytochrome c oxidase 1 DNA sequences unfeasible. These data suggest that Eriborus sp. could be used as a biological control agent for managing BTM infestations.

Inhibition of acetylcholinesterases of the pinewood nematode, Bursaphelenchus xylophilus, by phytochemicals from plant essential oils.

To understand the nematicidal mode of action of phytochemicals derived from plant essential oils against the pinewood nematode (Bursaphelenchus xylophilus), we evaluated 97 compounds (49 monoterpenes, 17 phenylpropenes, 16 sesquiterpenes, and 15 sulfides) for their inhibitory effects on B. xylophilus acetylcholinesterases (BxACEs). In the primary inhibition assay using B. xylophilus crude protein, more than 50% BxACE inhibition activity was observed with 3 monoterpenes, (+)-α-pinene, (-)-α-pinene, and 3-carene; 2 phenylpropenes, ο-anisaldehyde, and coniferyl alcohol; and 1 sesquiterpene, cis-nerolidol. Other compounds showed moderate or weak inhibitory activity. The inhibitory activities against 3 recombinant BxACEs were subsequently estimated using the identified active compounds in a primary inhibition assay. (+)-α-Pinene showed the strongest inhibition of BxACE-1 followed by 3-carene, coniferyl alcohol, (-)-α-pinene, o-anisaldehyde, and cis-nerolidol. The half maximal inhibitory concentration (IC50) values of (+)-α-pinene, 3-carene, o-anisaldehyde, cis-nerolidol, and (-)-α-pinene against BxACE-2 were found to be 0.64, 1.41, 8.18, 8.53, 15.28, and 18.03mM, respectively. Coniferyl alcohol showed the strongest inhibition of BxACE-3 followed by (+)-α-pinene and cis-nerolidol.

Acaricidal and Insecticidal Activities of Essential Oils and Constituents of Tasmannia lanceolata (Poir.) A.C.Sm. (Canellales: Winteraceae) Against Tetranychus urticae Koch (Trombidiformes: Tetranychidae) and Myzus persicae Sulzer (Hemiptera: Aphididae).

The negative side effects of synthetic pesticides have drawn attention to the need for environmentally friendly agents to control arthropod pests. To identify promising candidates as botanical pesticides, we investigated the acaricidal and insecticidal activities of 44 plant-derived essential oils (EOs) against Tetranychus urticae Koch and Myzus persicae Sulzer. Among the tested EOs, Tasmannia lanceolata (Poir.) A.C.Sm. (Tasmanian pepper) essential oil (TPEO) exhibited strong acaricidal and insecticidal activity. Mortality rates of 100% and 71.4% against T. urticae and M. persicae, respectively, were observed with TPEO at a concentration of 2 mg/ml. Polygodial was determined to be the primary active component after bioassay-guided isolation of TPEO using silica gel open-column chromatography, gas chromatography, and gas chromatography-mass spectrometry. Polygodial demonstrated acaricidal activity against T. urticae with mortality rates of 100%, 100%, 61.9%, and 61.6% at concentrations of 1, 0.5, 0.25, and 0.125 mg/ml, respectively. Insecticidal activity against M. persicae was also evident, with mortality rates of 88.5%, 85.0%, 46.7%, and 43.3% at respective concentrations of 1, 0.5, 0.25, and 0.125 mg/ml. Insecticidal and acaricidal activities of TPEO were greater than those of Eungjinssag, a commercially available organic agricultural material for controlling mites and aphids in the Republic of Korea. These findings suggest that TPEO is a promising candidate for mites and aphids control.

Seasonal occurrence of bark and woodboring Coleoptera in stands of Pinus densiflora (Pinales: Pinaceae) and Larix kaempferi (Pinales: Pinaceae) and monitoring method using multifunnel traps baited with pine volatiles.

This study investigated the seasonal occurrence of bark and woodboring Coleoptera in Pinus densiflora (Pinales: Pinaceae), and Larix kaempferi (Pinales: Pinaceae) stands using multifunnel traps baited with pine volatiles in Korea. The number and species of bark and woodboring beetles caught in traps baited with ethanol, α-pinene, and ethanol+α-pinene were compared to determine the effective attractants. In addition, the effects of other pine volatiles, such as (-)-ß-pinene, ß-caryophyllene, (±)-limonene, ß-myrcene, and 3-carene, were investigated. A total of 13,134 woodboring beetles from 150 species were collected from pine and larch stands from 2019 to 2020. Tomicus minor (Hartig) (Coleoptera: Curculionidae) adults were more attracted to traps baited with α-pinene, whereas Xyleborinus saxesenii (Ratzeburg) (Coleoptera: Curculionidae), Cyclorhipidion pelliculosum (Eichhoff) (Coleoptera: Curculionidae), and Phloeosinus pulchellus (Blandford) (Coleoptera: Curculionidae) adults were more attracted to traps baited with ethanol. Hylurgops interstitialis (Chapuis) (Coleoptera: Curculionidae), Shirahoshizo genus group, Rhagium inquisitor (Linne) (Coleoptera: Cerambycidae), and Rhadinomerus maebarai (Voss & Chûjô) (Coleoptera: Curculionidae) were more frequently attracted to traps baited with ethanol+α-pinene than to traps baited with other attractants. The addition of 3-carene to ethanol+α-pinene enhanced the capture of H. interstitialis, R. inquisitor, and Hylobius (Callirus) haroldi (Faust) (Coleoptera: Curculionidae).

Larvicidal activity of medicinal plant extracts and lignan identified in Phryma leptostachya var. asiatica roots against housefly (Musca domestica L.).

Medicinal plant extracts from 27 plant species in 20 families were tested for their larvicidal activity against housefly, 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, P. 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 LC(50) values of leptostachyol acetate against M. domestica larvae were 0.039 mg/g. Naturally occurring medicinal plant extracts and P. leptostachya var. asiatica root-derived compounds merit further study as potential housefly larval control agents or lead compounds.

Fumigant antifungal activity of Myrtaceae essential oils and constituents from Leptospermum petersonii against three Aspergillus species.

Commercial plant essential oils obtained from 11 Myrtaceae plant species were tested for their fumigant antifungal activity against Aspergillus ochraceus, A. flavus, and A. niger. Essential oils extracted from Leptospermum petersonii at air concentrations of 56 × 10(-3) mg/mL and 28 × 10(-3) mg/mL completely inhibited the growth of the three Aspergillus species. However, at an air concentration of 14 × 10(-3) mg/mL, inhibition rates of L. petersonii essential oils were reduced to 20.2% and 18.8% in the case of A. flavus and A. niger, respectively. The other Myrtaceae essential oils (56 × 10(-3) mg/mL) only weakly inhibited the fungi or had no detectable affect. Gas chromatography-mass spectrometry analysis identified 16 compounds in L. petersonii essential oil. The antifungal activity of the identified compounds was tested individually by using standard or synthesized compounds. Of these, neral and geranial inhibited growth by 100%, at an air concentration of 56 × 10(-3) mg/mL, whereas the activity of citronellol was somewhat lover (80%). The other compounds exhibited only moderate or weak antifungal activity. The antifungal activities of blends of constituents identified in L. petersonii oil indicated that neral and geranial were the major contributors to the fumigant and antifungal activities.

Identification of Sex Pheromone Components of Korean Dioryctria abietella (Lepidoptera: Pyralidae) Population and Synergism of Pheromone and Pine Cone Volatile Blends.

(9Z,11E)-tetradecadienyl acetate (9Z,11E-14:OAc) and (3Z,6Z,9Z,12Z,15Z)-pentacosapentaene (C25 pentaene), known as the sex pheromone of the European Dioryctria abietella population, were identified in the Korean D. abietella population. The ratio of 9Z,11E-14:OAc to C25 pentaene extracted from female pheromone glands was 1:23. The electroantennogram (EAG) response of male antennae to 9Z,11E-14:OAc was stronger than to C25 pentaene, whereas an opposite EAG response was observed in female antennae. Major volatile compounds in mature Korean pine cone (Pinus koraiensis), such as limonene, myrcene, and (-)-α-pinene, elicited dose-dependent EAG responses of male and female antennae. In field attraction testing, traps baited with 100:1,000, 100:2,000, and 100:3,000 ug of 9Z,11E-14:OAc to C25 pentaene were the most attractive to male D. abietella. More males were attracted to traps baited with 9Z,11E-14:OAc+C25 pentaene+limonene than traps baited with 9Z,11E-14:OAc+C25 pentaene. This showed that limonene acted as a synergist to sex pheromone. Delta traps, wing traps, and diamond traps were superior to bucket traps for capturing D. abietella males. This study showed that pheromone traps baited with 100:1,000 ~ 100:3,000 ug of 9Z,11E-14:OAc to C25 pentaene and limonene will be useful for the exact monitoring of D. abietella flight phenology in Pinus koraiensis Sieb. & Zucc. (Pinales: Pinaceae) forests.

Field Confirmation of (Z)-9-Heptacosene and (3Z,6Z,9Z)-Tricosatriene as Key Sex Pheromone Components of Korean Conogethes punctiferalis Guenée (Lepidoptera: Crambidae).

Recently, insufficient attractiveness of Conogethes punctiferalis Guenée adult males to sex pheromone, -(E)-10-hexadecenal and (Z)-10-hexadecenal, has been reported. To identify the other essential components of sex pheromone, male and female body extracts were analyzed. Two hydrocarbon components, (Z)-9-heptacosene (Z9-27:HC) and (3Z,6Z,9Z)-tricosatriene (Z3,Z6,Z9-23:HC), were identified from only female body extract. There was a significant difference in the electroantennogram (EAG) response of male antennae to Z3,Z6,Z9-23:HC and Z9-27:HC at all test concentrations compared to the response to the hexane control. In field attraction testing, the addition of Z9-27:HC and Z3,Z6,Z9-23:HC to binary aldehyde pheromones significantly increased trap catches of C. punctiferalis male adults. Based on the female and male body extract analysis and field attraction test, Z9-27:HC and Z3,Z6,Z9-23:HC were determined to be other essential sex pheromone components of the Korean C. punctiferalis population. No significant difference was observed in the number of male captures between the bucket trap and delta trap. Pheromone traps with a color close to yellow shade attracted more male adults than traps with a color close to blue shade.

Acaricidal Activities of Dioscorea japonica Thunb. (Dioscoreales: Dioscoreaceae) Extract and its Constituents Against the Two-spotted Spider Mite, Tetranychus urticae Koch (Trombidiformes: Tetranychidae).

The acaricidal activities of 86 plant extracts were investigated under laboratory conditions. The ethanol extract of Dioscorea japonica Thunb. root showed the strongest acaricidal activity, with 89.3% mortality against two-spotted spider mite, Tetranychus urticae Koch adults at a 2 mg/ml concentration. Bioassay-guided isolation of D. japonica root extract using silica gel open column chromatography, gas chromatography (GC), and gas chromatography-mass spectrometry (GC-MS) identified palmitic acid as the primary active compound. The acaricidal activities of palmitic acid against T. urticae were 91.2% and 69.7% at concentrations of 1 and 0.5 mg/ml, respectively. Among nine saturated fatty acids with carbon chains ranging from C8 to C26, the most vigorous acaricidal activity was observed with octanoic acid, followed by palmitic acid, and decanoic acid at a 1 mg/ml concentration. The acaricidal activity of the other fatty acids was less than 40% mortality at a 1 mg/ml concentration. These results indicate that a suitable carbon length is essential for fatty acids to exhibit acaricidal activity. The acaricidal efficacy of Eungjinssag (EJSG), an organic agricultural material authorized for the management of mites in the Republic of Korea, was compared to D. japonica root extract. At concentrations above 1 mg/ml, the acaricidal activity of D. japonica root extract was stronger than that of EJSG. The results of this study show that D. japonica root extract and palmitic acid are promising candidates as new environmentally-friendly control agents against two-spotted spider mite, which is one of the most severely damaging agricultural arthropod pests.

Matrix metalloproteinase (MMP)-9, but not MMP-2, is involved in the development and progression of C protein-induced myocarditis and subsequent dilated cardiomyopathy.

Repeated or continuous inflammation of the heart is one of the initiation factors for dilated cardiomyopathy (DCM). In previous studies, we established a DCM animal model by immunizing rats with cardiac C protein. In the present study, we analyze the role of matrix metalloproteinases (MMPs) in experimental autoimmune carditis (EAC) and subsequent DCM to elucidate the pathomechanisms of this disease. In this model, inflammation begins approximately 9 days after immunization. At that time, MMP activities were detected by in situ zymography. Real-time PCR analysis revealed continuous up-regulation of MMP-2 mRNA from 2 wk and thereafter. MMP-9 mRNA, however, had only a transient increase at 2 wk. Double staining with in situ zymography and cell markers demonstrated that gelatinase (MMP-2 and MMP-9)-expressing cells are infiltrating macrophages during the early stage and cardiomyocytes at later stages. Minocycline, which inhibits MMP-9 activities more strongly than MMP-2, significantly suppressed EAC, but an MMP-2-specific inhibitor, TISAM, did not affect the course of the disease. Furthermore, immunohistochemical examination revealed that minocycline treatment suppressed T cell and macrophage infiltration strongly, whereas TISAM did not. These findings indicate that MMP-9, but not MMP-2, is involved in the pathogenesis of the acute phase of EAC, and further suggest that MMP-9 inhibitors, minocycline and its derivatives, may be useful therapies for EAC and DCM.