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        검색결과 262

        161.
        2013.10 구독 인증기관·개인회원 무료
        Highland agriculture is a kind of specified agricultural term based on altitude and meteorological characteristics and their main crops are seed potato and vegetables. These crops are only cultivated in summer season when insect pests are most dynamically attacking such as diamondback moth (DBM, Plutella xylostella) and aphids son on. Aphids, insect virus vector, are really annoying factor, particularly in seed potato. Furthermore, these insect pests formed small sub-population or colony based on small field area. For instance, green peach aphid (GPA, Myzus persicae) populations’ genetic backgrounds and insecticide susceptibilities were different even in the same Pyeongchang area. Therefore, we suggested that highland agriculture should adopted IRM strategy for the control of insecticide-resistant aphids. First. Monitoring of annual fluctuation of insect population using traps for more effective monitoring. Second. Performing the insecticide resistant monitoring patch by patch or field using high throughput molecular diagnosis for more accurate monitoring. Third. Establishing the insect pest management program based on these results. We will deeply discussed practical monitoring results and IRM strategy in highland agriculture.
        162.
        2013.10 구독 인증기관·개인회원 무료
        The melon and cotton aphid Aphis gossypii Glover (Hemiptera; Aphididae) is one of the most serious pests worldwide. We surveyed insecticide susceptibility in A. gossypii field populations to 12 insecticides (6 neonicotinoids, 3 pyrethroids and 3 others) to examine resistance ratios. The levels of insecticide resistance were extremely high, especially to neonicotinoids, such as acetamiprid, clothianidin, thiacloprid and imidacloprid. To identify the neonicotinoid resistance mechanisms, we used an imidacloprid-resistant (IMI-R) strain as a model strain. IMI-R showed an extremely high resistance ratio and also cross-resistance to all the test neonicotinoids. However, there was little or no cross-resistance to the other insecticides, including sulfoxaflor. Synergist tests and enzyme activity assays suggested the absence of resistance mechanisms based on enhanced detoxification enzymes, such as cytochrome P450, esterase and glutathione S-transferase. One point mutation was found in the beta1 subunit loop D region of the nicotinic acetylcholine receptor (nAChR) of the IMI-R strain. This R81T point mutation was also found in field populations collected from 5 regions. Therefore, the R81T point mutation was identified as an important mechanism of imidacloprid resistance in A. gossypii.
        163.
        2013.10 구독 인증기관·개인회원 무료
        Wood boring insects are the major problem of many industries, such as hardwood brokers, importers, merchants, and manufacturers of furniture. Phosphine (PH3) is highly toxic to insects and is known to penetrate treated material. In this study, effectiveness of PH3 which is altered methyl bromide, was examined with Monochamus saltuaris, Platypus koryoensis, Cryphalus fulvus, and Xyleborus mutilatus. Fumigation to M. saltuaris, P. koryoensis, C. fulvus, and X. mutilatus was carried in a desiccator (12L) at 20℃ for 24 h. As a result, LC99 of PH3 to M. saltuaris, P. koryoensis, C. fulvus, and X. mutilatus was showed 0.455 mg L-1, 0.804 mg L-1, 0.243 mg L-1 and 0.046 mg L-1 in a desiccator(12L) at 20℃, respectively. M. saltuaris, P. koryoensis, C. fulvus, and X. mutilatus 100 % mortality was showed in a fumigation chamber (10 m3 and 100 m3) at normal temperature. In these results indicates that PH3 described could be useful for fumigant agent of 4 species wood pests.
        164.
        2013.10 구독 인증기관·개인회원 무료
        The potato tuber moth, Phthorimaea operculella (Zeller), is considered one of the main causes of potato losses during harvesting and storage. The pest occur throughout the year and its larvae damage the leaves, twigs and tubers. In this study, we have investigated the effects of ethyl formate (EF) and phosphine (PH3) against P. operculella. Fumigation to all stage of P. operculella was carried in a desiccator system at 5℃ and 20℃ for 24 h. As a result, LC99 of PH3 to all stage of P. operculella was showed 1.953 mg L-1 (eggs), 0.100 mg L-1 (larvae), 4.884 mg L-1 (pupae) and 0.240 mg L-1 (adults) at 20℃, respectively. LC99 of EF to all stage of P. operculella was observed 19.808 mg L-1 (eggs), 6.783 mg L-1 (larvae), 141.476 mg L-1 (pupae) and 3.223 mg L-1 (adults), at 20℃ respectively. Larvae and adults showed the highest susceptibility to PH3 and EF at 20℃. LC99 of PH3 to all stage of P. operculella was showed > 1.5 mg L-1 (eggs), 0.187 mg L-1 (larvae), > 1.5 mg L-1 (pupae) and 0.386 mg L-1 (adults) at 5℃ , respectively. LC99 of EF to all stage of P. operculella was showed 27.479 mg L-1 (eggs), 9.580 mg L-1 (larvae), 55.759 mg L-1 (pupae) and 3.084 mg L-1 (adults) at 5℃, respectively. These results indicated that the fumigant efficiency of PH3 and EF is more effective with treated in room temperatures against termites.
        165.
        2013.10 구독 인증기관·개인회원 무료
        The Japanese termite, Reticulitermes speratus Kolbe, is distributed in Korea widely. Although, termites are not currently a great problem in Korea, it might be increased commercial losses from imported timber. Phosphine (PH3) is very effective fumigant and is widely used to control pests. Oxygen treatment was found to enhance phosphine toxicity and reduce fumigation time against various life stage of insects. In this study, we determined efficacy of oxygenated phosphine fumigation for controlling R. speratus. Fumigation to adults of R. speratus was carried in a desiccator system at 20.9% (normal), 50% and 80% of oxygen concentration for 24 h. Fumigations under higher oxygen levels greatly increased phosphine toxicity to R. speratus. Mortality of termite was increased 15.0% and 16.2% in the 50.0% and 80.0% oxygen concentration with 0.25 mg L-1 phosphine at 5℃, respectively. 100% mortality was determined in 80.0% oxygen concentration with 0.5 mg L-1 phosphine at 5℃. Oxygenated phosphine fumigations have marked potential to improve insecticidal efficacy against R. speratus. These results merit further study as potential fumigant for control of wood destroying pests.
        166.
        2013.10 구독 인증기관·개인회원 무료
        This study was examined for activity of aggregation pheromone trap with residual effect of insecticides against Riptortus pedestris. Time of escape was from aggregation pheromone trap researched 49.74 min (ET99) and 65.01 min (ET99) with 1st and 2nd instar nymph respectively. Six insecticides for the stink bugs were treated to 3 different materials (wood, metal, and plastic). Bifenthrin and fenitrothion were showed 100% insecticidal activity at 48 h to all developmental stage of R. pedestris. Residual effect of bifenthrin and fenitrothion on plastic material were showed 100% insecticidal activity over 15 day after treatment with 1st, 3rd instar nymphs, and adults except 5th instars nymph. In field test using plastic material trap with two pesticides, 1st instar nymphs and adults were showed 100% mortality until 10 day after treatment. These results indicate that R. pedestris might be managed using aggregation pheromone trap with insecticides.
        167.
        2013.10 구독 인증기관·개인회원 무료
        The effect of electron beam irradiation on development and reproduction of imidacloprid-resistant (R strain) and -susceptible (S strain) Aphis gossypii were compared. Nymphs and adults of R and S strain were irradiated at target doses of 50, 100, 150, and 200 Gy. When nymphs were irradiated, emergence was not affected at all target dose, but number of F1 nymph was perfectly inhibited at 150 Gy in both strains. When irradiated to the adults, longevity slightly decrease at 150 Gy and above. Fecundity was strongly decreased at 100 Gy, but was not completely inhibited even at 200 Gy. Emergence of F1 nymph was decreased at 100 Gy and completely inhibited at 200 Gy. However, there were no significant differences on development and reproduction of R and S strain. We also conducted the comet assay immediately after irradiation and over the following 10 day period. Severe DNA fragmentation in A. gossypii cells was observed just after irradiation and the damage was repaired during the post-irradiation period in a time-dependent manner. These results suggest that electron beam irradiation induced abnormal development, reproduction, and DNA damage in A. gossypii, but there were no significant differences between R and S strain.
        168.
        2013.10 구독 인증기관·개인회원 무료
        A major concern in exporting agricultural commodities is the introduction or spread of exotic quarantine pests to the new area. To prevent spread of insect pests, various phytosanitary measures are used. In this study, we compared the effect of electron beam and X-ray irradiation on development and reproduction of the two-spotted spider mite, Tetranychus urticae. Eggs, nymphs, and adults were irradiated at target doses of 50, 70, 100, 150, 200, 250, and 300 Gy with electron beam and 10, 20, 30, 50, 70, 100, 150, and 200 with X-ray irradiation. When eggs were irradiated, egg hatching was completely inhibited at 150 Gy of electron beam and 50 Gy of X-ray irradiation. When irradiated to the nymphs, emergence was not affected at all target dose in both electron beam and X-ray irradiation. Hatchability of F1 generation was significantly decreased at 100 Gy of electron beam and 70 Gy of X-ray irradiation. When irradiated to the adults, longevity did not show any differences at all target dose in both electron beam and X-ray irradiation. These results suggest that the effect of X-ray irradiation was more potential than electron beam irradiation.
        169.
        2013.10 구독 인증기관·개인회원 무료
        Woolly apple aphid, Eriosoma lanigerum, one of the pests occurring in apple do damages on the branch and bastard slip nearby ground roots by sucking sap. Recently, seasonal population of this pest steadily increased but has scarcity the basic data relating to its ecology. This study was conducted to investigate the infested orchard ratio, environmental analysis of occurred orchard, seasonal population and parasite rate by Aphelinus mali, a natural enemy for woolly apple aphid, from 30 to 34 apple orchards, at 11 to 13 major apple producing areas in Gyeongsang-namdo and Gyeongsang-bukdo, Geolla-bukdo, and Chungchung-bukdo, during 2012 to 2013. It showed infested orchard ratio as about 35% and population density started to increase from mid-May, with its optimal density in late-June and increased again in late-September. This pest found in various rootstocks where infested orchards and could not found any significant pattern. The damage appeared in 9 to 35 year-old trees, severed rather old trees than younger trees. Also, orchards that did not eliminate bastard slip were showed high occurrence pattern. Parasite rates of Aphelinus mali showed the difference among investigated orchards but the rates showed generally increased pattern since early- July.
        170.
        2013.10 구독 인증기관·개인회원 무료
        Monochamus saltuarius, which mediates Bursaphelenchus xylophilus is one of the important vector of pine wilt disease recently. M. saltuarius showed difference with weight, growth, and oviposition according to species of trees. The most feeding amount and feeding area were determined in P. koraiensis. However, M. saltuarius almost did not feed and longevity was observed very short time only for 10 day in Sciadopitys verticillata. Weight, length and head width were measured the highest growth of M. saltuarius in P. koraiensis. Female of M. saltuarius was determined more growing than male of M. saltuarius in all species of trees. Tree preference for oviposition of M. saltuarius was the highest choice in P. densiflora. However, lots of scar for oviposition have observed but M. saltuarius laid less eggs in P. rigida. This result is related to bark thickness of trees. Ovipositional frequency has been consistently maintained to P. densiflora and P. koraiensis at 20 day intervals. In this study, physiological and ecological characteristic of M. saltuarius to preference of trees were researched could be helpful for managing of M. saltuarius.
        171.
        2013.04 구독 인증기관·개인회원 무료
        This study was conducted to estimate the control thresholds (CTs) at different larval densities of Oides decempunctatus Billberg (Coleoptera: Chrysomelidae) of Campbell early in the vineyard and investigated life cycle. Each stage of O. decempunctatus was sampled 18 times from May to September in 2010~2012. The seasonal occurrence of O. decempunctatus showed the highest peak in mid-late June and mid-late August. Overwintered O. decempunctatus's eggs were hatched from late May to early June. Larva period was from late May to mid July and adults appeared in mid July. The percentage of leaf damage (Y) of Campbell early inoculated by different densities of O. decempunctatus (X, no. of larvae/fruiting mother branch) for six weeks was estimated by Y= 0.498X+2.041 (R2=0.988) during vegetation period. The decreasing rate of soluble solid (Y) after grape harvest of Campbell early damaged by different densities of O. decempunctatus (X) was estimated by Y= - 0.046X+15.3 (R2=0.8543). Based of the relationships between the densities of O. decempunctatus larvae and the index of reducing soluble solid of Campbell early, the number of larvae (2nd to 3rd instar) which decreased less than 15°Bx loss of soluble solid was determined as the injury level of 7/fruiting mother branch.
        172.
        2012.10 구독 인증기관·개인회원 무료
        Fumigant effects of six plant essential oils (Helichrysum angustifolia, H. gymnocepha, H. splendidum, Arachis Hypogaea (peanut oil), Mentha arvensis (corn mint oil), and Thymus magnus (thyme oil) were tested against the adults of three grain storage insects (Lasioderma serricorne, Sitophilus zeamais, and Tribolium castaneum). Among them, the corn mint oil revealed to have fumigant toxicity against L. serricorne (LD50 = 1.3 ㎕ L-1), S. zeamais (LD50 = 3.6 ㎕ L-1), and T. castaneum (LD50 = 16.2 ㎕ L-1). The chemical constituents of corn mint oil were analyzed using GC-MS as follows: (-)-menthone (15.3%), isomenthone (10.0%), methyl-cetate (5.0%), β-caryophyllene (9.1%), and 1-menthol (48.1%). To enhance the fumigant toxicity, ethyl formate was added. This novel formulations of mixture could find significant differences in terms of their synergistic effects.
        173.
        2012.10 구독 인증기관·개인회원 무료
        Termites are a major problem for home and business owners around the world. Termites gnaw through wood and burrow under the foundations of buildings causing a great deal of damage to the structure of the building. Phosphine (PH3) is very effective fumigant and is widely used to control pests. PH3 rapidly penetrate through treated material, so it replaced many conventional fumigants for treatment of durable materials. In this study, we have investigated the effectiveness of PH3 fumigation on wood pests, Reticulitermes speratus kyushuensis. We evaluated two bioassay methods; wooden cube (10×10×10 cm) and insect breeding dish in comparison with effectiveness of PH3 penetrations into the timber block. Fumigation to adults of R. speratus was carried in a desiccator system for 24 h at 5 and 15℃. As a result, LC99 of PH3 to R. speratus in wooden cubes and insect breeding dish at 5℃ was 0.183 and 0.177 mg L-1, respectively. LC99 of PH3 in wooden cubes and insect breeding dish at 15℃ was 0.077 and 0.078 mg L-1, respectively. There were no significant differences between the two bioassay methods. Thess results indicate that PH3 described herein merit further study as potential fumigants for termite control.
        174.
        2012.10 구독 인증기관·개인회원 무료
        The cotton aphid, Aphis gossypii (Glover) (Hemiptera:Aphididae), is a highly polyphagous pest that directly or indirectly damages cultivated plants. Six field-collected populations of cotton aphid, A. gossypii (BY-A, BY-B, YJ-A, YJ-B, CJ-A, and CJ-B) were tested for susceptibility to 14 different insecticides. Most population exhibited high to very high levels of resistance to neonicotinoid. Among them, a strain showing resistance to imidacloprid were selected and showed 1,543-fold in resistance as compared with susceptible strain. Piperonyl butoxide (PBO), diethyl maleate (DEM), and S,S,S tributyl-phosphorothiolate (DEF) failed to synergize imidacloprid in this resistant population. In addition, the activity of detoxification enzymes (P450, EST, GST) were no differences between susceptibility and imidalcoprid resistance strain. However, by analyzing the nicotinic acetylcholine receptor β1 subunit loop D, R81T point mutation was detected in BY-A, BY-B, YJ-A, and YJ-B strain.
        175.
        2012.10 구독 인증기관·개인회원 무료
        The effects of electron beam irradiation on life stage and reproduction of Spodoptera litura were examined. Eggs, larvae, pupae, and adults were irradiated at target doses of 30, 50, 100, 150, 200, and 250 Gy. When eggs were irradiated with 100 Gy, egg hatching was completely inhibited. When irradiated to the larvae, pupation was inhibited at 100 Gy and larval period was delayed. When irradiated to the pupae, emergence was inhibited at over 100 Gy. When irradiated to the adults, longevity and fecundity did not show any differences. However, egg hatching was significantly decreased at 100 Gy and above. Also, electron beam irradiation was not induced the rapid death of S. litura. Reciprocal crosses between irradiated and unirradiated moths demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in S. litura adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage. The recovery of DNA damage in S. litura adults increased as time passed. but DNA damage hasn’t recovered fully. These results indicate that electron beam irradiation induced abnormal development and reproduction by DNA damage in S. litura. and as time goes by, the DNA damage was decresed.
        176.
        2012.05 구독 인증기관·개인회원 무료
        Methyl bromide (MB) is a widely used fumigant in most of the countries for quarantine purpose. However, MB has been phasing out and under control in many countries because it is listed as an ozone-depleting substance under the Montreal Protocol. In this study, we have investigated the effectiveness of phosphine fumigation on wood pests for developing an MB alternatives. We evaluated two bioassay methods; wooden cube (10×10×10 cm) and normal fumigation procedures in comparison with effectiveness of phosphine (PH3) penetrations into the timber block. Fumigation to adults of Reticulitermes speratus was carried in a desiccator system for 24hr at 5 and 15 ℃. As a result, LC99 of PH3 to R. speratus in wooden cubes and insect breeding dish at 5℃ was 0.183 and 0.177 mg L-1, respectively. LC99 of PH3 in wooden cubes and insect breeding dish at 15℃ was 0.077 and 0.078 mg L-1, respectively.
        177.
        2012.05 구독 인증기관·개인회원 무료
        The cotton aphid, Aphis gossypii Glover is an important sap-sucking pest of many pant, including cucumber and pepper. The objective of the present study was to determine the effects of sublethal concentrations of two insecticides (imidacloprid and flonicamid) and the action mechanisms on the feeding behavior of A. gossypii. The median lethal concentrations (LC50) of imidacloprid and flonicamid for adult A. gossypii were 2.01 and 1.92 ppm, respectively. The sublethal concentrations of imidacloprid were 0.22 ppm (LC10) and 0.82 ppm (LC30), and those of flonicamid were 0.094 ppm (LC10) and 0.56 ppm (LC30). The developmental period of A. gossypii nymphs at LC30 was 3.6 days for both insecticide which shorter than controls (4.2 days). Adult longevities at LC10 and LC30 of imidacloprid were 15.2 and 13.6 days, respectively. Adult longevity at LC10 and LC30 of flonicamid was 11.1 and 9.9 days, respectively. Control adult longevity was 15.5 days. Total fecundity was decreased at both sublethal concentration of two insecticides. Feeding behavior analysis using an electrical penetration graph showed that sublethal doses of imidacloprid and flonicamid had significant effects on the duration of phloem ingestion. However, higher doses of flonicamid induced starvation by inhibition of phloem ingestion and higher doses of imidacloprid induced contact toxicity rather than inhibition of feeding behavior.
        178.
        2012.05 구독 인증기관·개인회원 무료
        The influence of electron beam irradiation on each developmental stage and reproduction of Spodoptera litura were examined. Eggs, larvae, pupae, and adults were irradiated at target doses of 30, 50, 100, 150, 200, and 250 Gy. When eggs were irradiated with 100 Gy, egg hatching was perfectly inhibited. When irradiated to the larvae, pupation was inhibited at 100 Gy and larval period was delayed. When irradiated to the pupae, emergence was inhibited at 100 Gy and above. When irradiated to the adults, longevity and fecundity did not show any differences. However, egg hatching was strongly decreased at 100 Gy and above. Also, electron beam irradiation was not induced the instantaneous death of S. litura. Reciprocal crosses between irradiated and unirradiated moths demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in S. litura adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage. These results suggest that electron beam irradiation induced abnormal development and reproduction by DNA damage in S. litura.
        179.
        2012.05 구독 인증기관·개인회원 무료
        Insecticidal susceptibilities of 16 registered insecticides on each developmental stages of Phthorimaea operculella were investigated and further examined the contact, oral and residual toxicities after chosen from insecticides showing good effect. Mortality, longevity and effect on reproduction of 16 insecticides to P. operculella adults were also investigated. To the eggs and pupae, only spinosad showed 71.1% inhibition rate of egg hatch and 66.7% inhibition rate of emergence. To the 3rd nymphs, fenitrothion (LC50 336.6 ppm), esfenvalerate (LC50 8.6 ppm), ethofenprox (LC50 35.7 ppm), and emamectin benzoate (LC50 0.05 ppm) showed oral toxicity over 90% and esfenvalerate (LC50 0.87 ppm), ethofenprox (LC50 16.5 ppm), emamectin benzoate (LC50 0.53 ppm), and spinosad (LC50 2.48 ppm) showed the contact toxicity over 90%. To the adults, mortalities of insecticides were showed as below: deltamethrin and spinosad showed perfect mortality 48 h after treatment; esfenvalerate, ethofenprox, and thiamethoxam showed 40 - 60% mortalities; but the others are not showed any effect. Fecundities of female adults were inhibited by esfenvalerate, emamectin benzoate, and dinotefuran, compare to that of the control, but there were no statistical differences to that of ethofenprox, benfuracarb, thiamethoxam, clothianidin, and diflubenzuron. Adult longevity was showed no difference compare to that of the control. Residual effect of emamectin benzoate showed perfect insecticidal activity at 14 days after treatment and the next ethofenprox showed over 90% at 7 days after treatment.
        180.
        2011.10 구독 인증기관·개인회원 무료
        Testes‐derived unipotent male germ‐line stem (GS) cells can acquire multipotency under appropriate culture conditions to become mGS cells which can contribute to all three germ‐layers. This study was designed to investigate the epigenetic characteristics of mGS cells derived from adult mouse testes (maGS cells). The GS cells were isolated from 4 6 week DBA mouse and were cultured in Dulbecco’s modified Eagle Medium supplemented with 15% (v/v) fetal bovine serum, 1,000 U/ml LIF, 4 ng/ml GDNF at 37℃ in an humidified atmosphere of 5% CO2 in air to derive the maGS cells. The multipotency of maGS cells were verified by morphological and gene expression analyses, teratoma formation upon transplantation into nude mouse and in vitro differentiation ability. Bisulfite genomic sequencing revealed that GS cells had androgenetic DNA methylation pattern at the Igf2‐H19, Gnas‐Nespas , and Dlk1‐Dio3 imprinted gene clusters which changed to hemi‐zygotic embryonic stem (ES)‐cell like pattern in the maGS cells. Western blot analysis, using modification‐ and residue‐specific antibodies, revealed that both maGS and ES cells had similar level of histone di‐methylation at 4th and 27th lysine residue of histone 3 (H3K4me2 and H3K27me2) which represent “bivalent domain” for regulating self‐renewal and differentiation of mouse ES cells. Both maGS and ES cells also shared similar hisone modification for H3K9me2, H3K79me2, H3K9ac and H3K18ac. However, maGS cells had higher level of H3K- 36me2 and H3S10p. These data suggest that maGS and ES cells share several epigenetic characteristics but they also have their own unique epigenetic marks that may be useful as a molecular marker for their identification.