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        검색결과 7

        1.
        2010.10 구독 인증기관·개인회원 무료
        The two related species in the tribe Archipini, Adoxophyes paraorana and Pandemis heparana (Lepidoptera: Tortricidae), are insect pests of fruit trees in Korea. We investigated differences in pheromone system and seasonal flight of these two species. GC-MS analyses of pheromone gland extracts revealed that females of both species produce blends of Z11-14:OAc, Z9-14:OAc, and Z11-14:OH in similar ratios. The average ratio of three components in extracts was estimated to be 3:100:0.3 for A. paraorana and 3:100:2 for P. heparana. Field tests showed that Z11-14:OAc and Z9-14:OAc were essential for attraction of A. paraorana males and the presence of Z11-14:OH in primary binary blend did not induce any synergistic or inhibitory effect. For the attraction of P. heparana males, however, all three components, Z11-14:OAc, Z9-14:OAc and Z11-14:OH, were indispensable. These results suggest that male A. paraorana do not discriminate between conspecific females and those of P. heparana in the field. Comparison of the flight phenologies in apple and pear orchards showed that the two species are sympatric and overlap in flight periods. This finding eliminates pheromone specificity and seasonal separation as premating reproductive isolation mechanism between A. paraorana and P. heparana.
        2.
        2010.05 구독 인증기관·개인회원 무료
        This study was conducted to develop economic injury level (EIL) and economic threshold (ET) of onion thrips, Thrips tabaci on welsh onion (Allium fistulosum L. var). The changes of welsh onion biomass and T. tabacci density were investigated after introductions of T. tabacci at different densities and days: By the results of the experiment in the early welsh onion cultivation periods (30d after transplanting), the biomass of welsh onion significantly decreased with increasing the initial inoculated density of T. tabacci. The relationship between cumulative insect days (CID) and yield loss (%) of welsh onion was well described by a nonlinear logistic equation. Using the estimated equation, EIL and ET of T. tabacci on welsh onion were estimated at 24 and 20 CID per plant, respectively. By the results of the experiment in the late cultivation periods of welsh onion (about 120d after transplanting), the welsh onion biomass was also significantly different inoculation thrips densities to welsh onion. The EIL and ET were calculated as 35 and 28 thrips per welsh onion plant. Until a more elaborate EIL-model is developed, the present result may be useful for T. tabacci management during the cultivations of welsh onion.
        3.
        2010.05 구독 인증기관·개인회원 무료
        This study was conducted to evaluate the effects of temperature and nematicides on endospore attachment characteristics of 2 Korean isolates of nematodeparasitic bacteria, Pasteuria penetrans. P. penetrans CJ-1 and 98-35 isolates and 3 species of root-knot nematodes in U. of Florida were used ; Meloidogyne incognita (MI), M. arenaria (MA), and M. javanica (MJ). Three nematicide levels of 2, 4, and 6 ppm were compared by treating Vydate and Nemacur in the endospore containing soils. The endospores were attached to the root-knot nematode juveniles by centrifugal method. Reproduction of the isolates was checked by observing root-knot nematode females harvested from inoculated tomato roots. 1. Among the two Korean isolates, 98-35 showed attachments to MI, MA, and MJ juveniles, but it could not reproduce in any species. CJ-1 reproduced on all the 3 tested root-knot nematode species. 2. Endospores pretreated in -14°C showed higher attachment rate than those pretreated in 4, 24, and 40℃. 3. Nemacur treatments significantly suppressed the attachment of the endospores to the juveniles, while Vydate treatment effects were negligible.
        4.
        2010.05 구독 인증기관·개인회원 무료
        A storage mite (cheese mite), Tyrophagus putrescentiae, is known as the pest in storing grains and common health pest species in the dust around home. The mite directly affect our well-being as parasites, vectors of disease, and producers of allergens. But recently we found damages in horticultural crops especially in greenhouses. It is very difficult to diagnose the damage by the mite because of the tiny size of the mite. And the symptom is not clear at the beginning stage. In this study, observations were done on the mite and the crop damage symptoms in several horticultural crops under dissecting microscope and scanning electron microscope (SEM). The mite body size was 0.3~0.5㎜ and they had long hairs all around their body when observed under SEM. The characteristic damage symptoms in some horticultural crops are as follows. In phalaenopsis, the flower buds became yellow and the lower side of the leaves had white spots. The surface of young cucumber fruits became shiny and soft at the early damage stage. In the crops, the damaged surfaces became corky as the plants grew up. In peach tree, whole the trees lost vigor and flower drops were observed when the mite density was very high in greenhouse cultivation.
        5.
        2010.05 구독 인증기관·개인회원 무료
        Synanthedon haitangvora (Lepidoptera: Sesiidae) is an economically important pest of apple trees in Korea and China. We report here the identification of compounds in pheromone gland extracts of female S. haitangvora, and the male responses to blends of different components and ratios in the field. Two major components from pheromone gland extracts of S. haitangvora females were identified as Z3,Z13-18:OAc and E2,Z13-18:OAc, and the average ratio of these components was about 1:1. Seven minor components, Z9-16:OAc, Z11-16:OAc, Z9-18:OAc, Z13-18:OAc, E3,Z13-18:OAc, Z3,Z13-18:OH, and E2,Z13-18:OH, also were identified from gland extracts. Field tests showed that male S. haitangvora were attracted to Z3,Z13-18:OAc alone, but the maximum number of males was attracted to the binary blend of Z3,Z13-18:OAc and E2,Z13-18:OAc mimicking the blend found in female extracts. The addition of minor components to a 1:1 blend of Z3,Z13-18:OAc and E2,Z13-18:OAc did not increase the numbers of moths captured. The only significant effect of minor components was the strong inhibitory effect of adding Z3,Z13-18:OH to the primary binary blend. Increasing doses of the optimum pheromone blend in the lures from 0.1 to 2.0 mg increased trap catches of male S. haitangvora.
        6.
        2008.10 구독 인증기관·개인회원 무료
        We tested differences in female pheromone production and male response in three species of the genus Adoxophyes in Korea. Females of all three species produced mixtures of Z9-14:OAc and Z11-14:OAc as major components but in quite different ratios. The ratio of Z9-14:OAc and Z11-14:OAc in pheromone gland extracts was estimated to be 100:198 for A. honmai, 100:23 for A. orana, and 100:3880 for A. sp. Field tests showed that males of each species were preferentially attracted to the two-component blends of Z9-14:OAc and Z11-14:OAc mimicking the blends found in pheromone gland extracts of conspecific females. The effects of minor components identified in gland extracts on trap catches varied with species. Addition of 10me-12:OAc or E11-14:OAc to the binary blend of Z9-14:OAc and Z11-14:OAc significantly increased captures of A. honmai males, whereas E11-14:OAc exhibited a strongly antagonistic effect on catches of A. sp. males. Moreover, Z9-14:OH or Z11-14:OH added to the binary blends increased attraction of male A. orana but not A. honmai and A. sp. males, suggesting that these minor components, in addition to the relative ratios of the two major components, play a noteworthy role in reproductive isolation between Adoxophyes species in the southern and midwestern Korea where these species occur sympatrically.