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        검색결과 9,757

        3787.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to elucidate the genetic relationships among native Korean cattle breeds by analyzing genetic variations and distances. Relationships among Hanwoo, Korean brindle, Korean black, Jeju black, and Holstein cattle were evaluated using 15 microsatellite markers. Korean brindle and Korean black cattle had the closest relationship based on the lowest genetic distance being observed between these breeds. A Neighbor-Net tree created using the Reynolds distances indicated that Korean brindle and black cattle formed a group separate from the Hanwoo population. However, an Fst pairwise test revealed that Hanwoo, Korean brindle, and Korean black cattle differed significantly (P <0.01). Moreover, the results of this study confirmed that Jeju black cattle became a separate established breed in Korea through a path different from that of cattle from inland regions, even though it is considered to be a Korean native breed. Overall, the results of our study indicate that Korean brindle and black cattle are indeed native Korean breeds that maintain an endangered status.
        4,000원
        3789.
        2015.04 구독 인증기관·개인회원 무료
        Three formula types (gel, cookie, and liquid), six commercial roach bait products containing one of active ingredients among Fipronil, Avermectin, Dinotefuran, and Chlorpyrifos were examined against susceptible strain of German cockroach, Blattella germanica (L.). For the results of killing speed (LT50 values), universal killing speed effects depended on bait formula types. The killing speed of liquid bait formula type was the fastest among three formula types. Followed by gel bait type and cookie bait type. However the control speed (LT90 values) effects depended on the active ingredients that contained in roach baits. The baits contained Fipronil were shown the strongest control performance against German cockroaches. Chlorpyrifos was similar with Fipronil. Followed by Avermectin and Dinotefuran.
        3790.
        2015.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi have been studied to develop for biological control agents as an alternative to chemical control agents in insect pest management. Two Lepidopteran insects, Spodoptera exigua and Plutella xylostella, are serious insect pests infest various crops, but not effectively controlled by commercial chemical pesticides due to its high insecticide resistance. A fungal isolate was isolated from S. exigua larvae collected from green onion field in Andong, Korea. To identify the fungal isolate, 18srRNA sequence for internal transcribed spacer (ITS) and β-tubulin regions were sequenced. The ITS and β-tubulin sequence were highly matched to Beauveria bassiana and morphological characteristics also was fit to known B. bassiana. Finally, isolated fungus has identified as B. bassiana and named B. bassiana ANU1. The result of bioassay, median lethal concentrations were 2.7×103 and 0.9×103 conidia/ml and medial lethal times were 65.6 and 60.8 h to S. exigua and P. xylostella, respectively. B. bassiana ANU1 showed high pathogenicity to two insect pests from 20℃ to 30℃ at 50% relative humidity (RH) and more than 40% RH at 25℃ with 107 conidia/ml of concentration.
        3791.
        2015.04 구독 인증기관·개인회원 무료
        The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), has been considered as a major thrips species after its invasion in 1993 in Korea although recently F. intonsa (Trybom) was found as a dominant species locally. To explain their asymmetrical abundance in the field, we hypothesized differential insecticide susceptibility of both thrips species as an underlying mechanism. Laboratory assays were conducted to know their susceptibility to different pesticides including chlorfenapyr, chlorpyrifos, thiamethoxam, spinosad, s-metolachlor, and metalaxyl by direct spray, residue, and oral ingestion. Results showed that both thrips species were highly susceptible to chlorfenapyr and mortality reached 100% within 12 hours in F. occidentalis in all the assays while 9 hours in F. intonsa in direct spray and residual assays. The LT50[h] values of tested insecticides were significantly lower than that of herbicide or fungicide regardless of exposure methods except metalaxyl from direct spray. The insecticides tested here differed considerably in species specific toxicity, and F. intonsa is generally more susceptible to the insecticides irrespective of exposure methods.
        3792.
        2015.04 구독 인증기관·개인회원 무료
        Frankliniella occidentalis (Pergande) is an anthophilus pest of many greenhouse and field crops worldwide. We compared the influence of constant (27.3ºC) and fluctuating temperatures (23.8 to 31.5ºC, with an average of 27.3ºC) on the life table characteristics of F. occidentalis held at a 16:8 h L:D photoperiod and 45 ± 5% RH. The development times from egg to adult of F. occidentalis were significantly affected by temperature fluctuation and sex. Survival of immature life stages was higher under fluctuating than constant temperature. Total first instar larvae/female was not significantly different (58.7 at constant and 60.5 at fluctuating temperatures) but daily production of first instars was higher in constant temperature than fluctuating temperatures (3.3 at constant temperature and 3.1 at fluctuating temperatures). The off-spring sex ratio was not significantly different between constant and fluctuating temperatures. The intrinsic rate of natural increase (rm), net reproductive rate (R0), finite rate of increase (λ), mean generation time (tG), and doubling time (tD) were affected significantly by fluctuation of temperature. The intrinsic rate of natural increase of F. occidentalis was higher in constant temperature (0.1808) than did in fluctuation of temperatures (0.1733). Thus, this study show that variable temperatures influence population growth rates of F. occidentalis.
        3793.
        2015.04 구독 인증기관·개인회원 무료
        Spotted wing drosophila (SWD), Drosophila suzukii, is one of the most harmful pests causing serious damages to blueberries in Northern America and Europe. It is essential to seek alternatives to methyl bromide to ensure dis-infestation of this pest from agricultural products. We investigated the effect of X-ray irradiation (0, 50, 100, 200 and 300 Gy) on development and reproduction of SWD to meet this standard. When eggs were irradiated with the doses, some portion of the eggs hatched even at 300 Gy. The larvae hatched from the irradiated eggs did not pupate at 300 Gy, and they could not develop to adults even at 50 Gy. When larvae were irradiated, they developed up to pupa in some proportion. However above 100 Gy, there was no adult emergence. When pupae were irradiated, some of them emerged to adults. However, the adults could not produce eggs at all above 100 Gy. When adults were irradiated, oviposition occurred normally, but fecundity and hatchability were decreased as irradiation dose went up.
        3794.
        2015.04 구독 인증기관·개인회원 무료
        In this study, the damage on the leaves of Liriope spicata (Thunb.) Lour. by a psychid species, Mahasena aurea (Butler), is reported for the first time from Korea. Adult of both sexes and larva were redescribed with illustration of the external characteristics, including the genitalia of male, adults, larvae, pupae and all the available information.
        3795.
        2015.04 구독 인증기관·개인회원 무료
        Vespa crabro is a cosmopolitan social wasp species whereas Vespa analis is commonly found in Asia. Both species are widely distributed in Korea and known to be aggressive when disturbed, resulting in frequent sting accidents. Although major venom components of well known Vespa wasps have been reported, no comparative transcriptomic analysis of venom gland between V. crabro and V. analis has been conducted to date. To investigate the differences in venom properties between these two wasps, total RNA was extracted from each venom gland and used for RNA-sequencing. A total of 31 venom-specific genes were identified in both venom gland transcriptomes but their expression profiles were different between V. crabro and V. analis. Venom allergen 5, premastoparan A and phospholipase A were the top three genes that were most prevalently transcribed in the venom gland of V. crabro, and their transcription rates were 902-, 112- and 4164-fold higher compared with V. analis, respectively, as judged by FPKM values. Their differential transcription profiles were confirmed by quantitative real-time PCR. In the venom gland of V. analis, however, premastoparan A was most abundantly transcribed gene, followed by calponin and tropomysin. In general, most venom-specific genes were more abundantly expressed in V. crabro but some genes exhibited higher transcription rates in V. analis, including muscle LIM protein, troponin, paramyosin, calponin, etc. Our findings suggest that V. crabro produce venom with much more enriched venom components, thereby with higher toxicity compared with V. analis.
        3796.
        2015.04 구독 인증기관·개인회원 무료
        Species diversity of ant fauna inhabiting the university campus in the Seoul Metropolitan city, Hanyang University is documented in this investigation. Totally, 14 species of 8 genera belong to 3 subfamilies discovered in study area. Our results are compared with the previous works on ant fauna in the forest and urban habitats based on species number difference. In study area, site 12 and 13 contain wide forest area and diverse environmental elements such as rotten wood, leaf mold and group of living tree. Site 7 has small forest area, but show wide variety of environments like site 12 and 13. Urbanized region like site 8, 10 or area in construction like site 1 show the most lowest diversity. Aside from diversity, Four ant species, Paratrechina flavipes, Lasius spp., Camponotus japonicas, Tetramorium caespitum, appear at almost all habitat, seems to have strong tolerance to environmental change.
        3797.
        2015.04 구독 인증기관·개인회원 무료
        Distribution and abundance of species are influenced by their environmental condition. Among various environmental factors, a vegetation is one of the most influential factors, because it is used as habitats as well as food resources. Arthropods including insects play a important role in forest ecosystems as grazers, scavenger, predators, etc. Deciduous and coniferous forests have different plant community composition, resulting in different environmental condition. In this study, we collected arthropod communities at two different deciduous and coniferous forest stands in the Mountain Gariwang. At each stand, three different sampling methods were used: soil core for soil macroinvertebrate, pitfall trap for wandering insects, and sweeping net for insects in the shrups. Therefore, sampling was conducted at vertical habitats in the forest. The results showed that there were no difference in the number of orders from soil at both coniferous and deciduous stands. However, the abundance was higher at coniferous stand than at deciduous stand. Collembola was the dominant taxa in soil. Meanwhile, there were no statistically significant differences of community composition between coniferous stand and deciduous stands. Multivariate analyses was conducted to characterize differences of communities at different stands as well as vertical distribution in forest.
        3798.
        2015.04 구독 인증기관·개인회원 무료
        Genus Tautoneura Anufriev, 1969 (Hemiptera: Auchenorrhyncha: Cicadellidae: Typlocybinae) were recorded 59 species in the world. Among them, only 1 species: Tautoneura mori has been recorded so far in the Korean Peninsula. Tautoneura mori is known as a major pest of Mulberry in China and Japan, and we also confirmed that it appears on Mulberry in Korea. In this talk, we confirmed two new records: Tautoneura japonica, Tautoneura tricolor to the Korean typhlocybinae fauna, and we also discovered one new species to science. Additionally, we provide biological information such as host plants and distributional records, with a key to the Korean Tautoneura species. We also discuss potential status of each species as an agricultural pest concerning its biological traits.
        3799.
        2015.04 구독 인증기관·개인회원 무료
        Vollenhovia emeryi (Hymenoptera: Myrmicinae) is dimorphic in its wing morphology of alate females: the long-winged and the short-winged. In our previous study, we found that the long-winged is ancestral and the short-winged is derived. Intriguingly, the former is infected with the intracellular symbiotic Wolbachia bacterium and the derived is void of the bacterium indicating that the latter somehow evolved resistance to the bacterium. This may be one of few cases in which transition from susceptibility to the bacterium can be traceable via the divergence estimation. As a consequence, we inferred that the two morphs diverged approximately quarter million years ago; a remarkably recent event in evolutionary perspective. In this presentation, we will further discuss genetic orchestration in the host insect and future research directions.
        3800.
        2015.04 구독 인증기관·개인회원 무료
        Spotted wing drosophila, Drosophila suzukii, native to eastern and southeastern Asia, has become one of the most harmful pests causing serious damage to fruits such as blueberry, cherry, and others in Northern America and Europe. For quarantine sanitary purpose, methyl bromide (MeBr) has been used for a long time. However, it is under regulation because of its adverse effect of ozone layer depletion. Thus, alternative strategies to MeBr are needed to meet the quarantine requirement. In this study, we investigated effects of gamma ray irradiation (0, 50, 100, 200 and 300 Gy) on the development and reproduction of D. suzukii to offer a guideline in using gamma ray for dis-infestation of this pest. The higher doses of gamma ray caused more adverse effects on development and hatchability of D. suzukii. Development and oviposition of D. suzukii was significantly depressed at above certain doses, respective to each developmental stage. When eggs were treated with the doses of gamma ray, eggs hatched in some ratios at all doses. Even though some larvae developed to pupae under 100 Gy irradiation, all these pupae did not emerge to adults at all doses. When larvae were treated with gamma ray, some of them pupated at each doses. However these pupae did not emerge to adults at all under all doses. When pupae were irradiated, the emerged adults did not oviposit eggs above 100 Gy. When adults were irradiated, oviposition occurred normally, but fecundity and hatchability of the eggs were reciprocal to the doses.