• Journal of Life Science
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• v.10 no.4
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• pp.403-407
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• 2000

For the biological control of the root-lesion nematodes, Pratylenchus spp., which damage directly and indirectly to the leaf perilla, the nematical effect of three nematode-trapping fungi, Arthrobotrys oligospora, A. conoides and A. dactyloides was evaluated in the field. Three species of Arthrobotrys were isolated from the culture soil of leaf perilla in 1998 and were observed the capture of the root-lesion nematodes, Pratylenchus spp. by adhesive hyphal networks or constricting rings on agar. At 40 days after treatment, the plant-parasitic nematodes and root-lesion nematode populations were approximately increased 3.5 fold in untreated control plot, while the nematode population in fungi treatment plots was similar to initial population. In the A. dactyloides plot, however, the population of plant-parasitic nematodes and Pratylenchus spp. was approximately reduced 65% and 53%, respectively. Thus, the fungus A. dachyloides should provide as biological agent for the control of Pratylenchus spp.

• Journal of Apiculture
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• v.32 no.3
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• pp.191-198
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• 2017

Vespa hornets are notorious predators of honeybees in Korean beekeeping. Detection of vespa hornet attacking on honeybee colony was tried through analysis of wing beat frequency profiling from Vespa mandarinia. Wing beat profiles of V. mandarinia during active flight and resting were distinctively different. From the wing beat profiling, algorithm of automated detection of vespa attack was encoded, and alert system was developed using Teensy 3.2 and Raspberry pi 3. From the laboratory testing, the prototype system successfully detected vespa wing beats and delivered the vespa attack information to the user wirelessly. Further development of the system could help precision alert system of the vespa attack to apiary.

• The Journal of the Petrological Society of Korea
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• v.11 no.3_4
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• pp.157-168
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• 2002

In Gimcheon area of the central Yeongnam massif granite gneiss occurrs with intercalated biotite gneiss at xenolith or restite. In order to understand the evolution of the central Yeongnam massif, it is essential to have absolute age information, but not many age data are available yet. Furthermore the previous age determinations from the study area are not compatible with the outcrop relationship. In this study we determined chemical ages from the zircon grains. We obtained ages of $1970\pm$ 78(l$\sigma$)Ma from the granite gneiss, $1814\pm$77(l$\sigma$)Ma from the outer rim of a rounded zircon and 1973$\pm$97(l$\sigma$)Ma from a longish zircon, both from the biotite gneiss. These ages seem to indicate the timing of granitic magma intrusion and subsequent metamorphism. Ages of $2954\pm$ 158($l\sigma$)Ma, 2440$\pm$58(l$\sigma$)Ma, and 2219$\pm$36($l\sigma$)Ma obtained from zoned core of the rounded zircon grain from the biotite gneiss suggest various geological events before such metamorphism of the biotite gneiss. Ages in the range of 1450~1670 Ma observed in zircons of both gniesses suggest later metamorphism that the granite gneiss and the biotite gneiss experienced together. The chemical age determination by electron probe micro-analyzer of this study utilized 1$\mu\textrm{m}$ beam diameter and it seems to be a very useful age determination from the zircons with complex growth history because of superior spatial resolution.

• The Journal of the Petrological Society of Korea
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• v.25 no.2
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• pp.121-142
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• 2016

The Satkatbong pluton was studied with other plutons together, but some fundamental petrological characteristics were missing. This study mainly reports the petrography and geochemistry of the Satkatbong pluton comparing with the Daebo and the Bulguksa granitoids in south Korea. The Satkatbong pluton, which is host rock including a number of Mafic Magmatic Enclaves (MME), is north-south shaped dioritic pluton, located along the east coast of south Korea. The Satkatbong pluton seems to be unconformable with Cretaceous sedimentary rocks from fieldwork result. In geochemistry, the Satkatbong pluton, which is roughly similar with the Daebo granitoids, is classified into calc-alkali series rock and volcanic arc granitoid Tectonically. The fact that AlT value in marginal parts of amphiboles in the Satkatbong pluton is lower than other granitoids implies emplacement depth of the Satkatbong pluton was relatively shallow. The Satkatbong pluton shows different geochemical feature compared to the adjacent adakitic Yeongdeok granite. This seems to be caused by mafic mantle material expected from the occurrence of MMEs.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.349-356
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• 2007

Three active components (Z8-12:Ac, E8-12:Ac, and Z8-12:OH) are known in sex pheromone of the oriental fruit moth, Grapholita molesta, and have been commercially available to apply for population monitoring and mating disruption. However, there have been variation among commercial products in pheromone composition and amount impregnated in each pheromone releaser. This study was performed to optimize factors influencing on pheromone monitoring of G. molesta by analyzing pheromone composition/amount, effective period of releaser, and trap type/placement in apple trees. High purity of Z8-12:Ac component was effective to attract males, in which 96% or more of cis acetate isomer component appeared to be optimal composition. Pheromone amounts ($0.01-1\;{\mu}g$) impregnated in each rubber dispenser did not give significant effect on monitoring during 90 days from June to August. "Delta" trap was much more efficient than "cone" trap to collect males. Trap installation was another factor, in which placing traps at canopy level was much efficient than at trunk or ground levels. Pheromone trap monitoring with these optimal factors indicated three to four adult peaks from June to September in addition to high overwintering population from April to May in pesticide-applied orchards in Andong, Korea.

• Korean journal of applied entomology
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• v.59 no.1
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• pp.15-22
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• 2020

Two tephritid fruit flies are infesting pumpkins in Korea. Both are classified into genus of Zeugodacus. The striped fruit fly, Z. scutellata, males are attracted to a lure called Cuelure (CL), which has been used to monitor the occurrence of this fruit fly in the crop field. In contrast, no effective male lure was not developed to monitor the pumpkin fruit fly, Z. depressa. Protein diet lure has been used to attract females of most fruit flies. The addition of terpinyl acetate (TA) was effective to increase the attractiveness of Z. depressa. This study aimed to monitor the occurrence of Z. depressa in pumpkin field with TA-protein diet lure. To validate the efficiency of TA-protein diet lure, Z. scutellata was monitored in a year of 2019 using CL and TA-protein diet lures, and the yearly monitoring data were compared. The occurrence patterns derived from both lures were similar except late season after October. The extended catches of TA-protein diet lure might be explained by the adult diapause induction of Z. scutellata at late September. Monitoring Z. depressa with TA-protein diet lure gave two peaks at mid July and August-September, in which more than 80% catches were females. Based on the attractiveness of TA-protein diet lure, its wettable powder with an addition of spinosad insecticide was formulated and sprayed to pumpkin crops. After 7 days post-spray, the control efficacy recorded more than 70%. However, the control efficacies decreased as the time progressed after the spray. These results demonstrated the application of TA-protein diet lure for monitoring occurrence of Z. depressa in pumpkin-cultivating field conditions. The wettable powder containing spinosad can be applied to develop a new control agent against two pumpkin fruit flies.

• Economic and Environmental Geology
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• v.47 no.6
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• pp.571-588
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• 2014

It consists of the Precambrian Jirisan metamorphic complex and Sancheong anorthosite complex and the Mesozoic granitoids which intrude them in the Sancheong area, the Jirisan province of Yeongnam massif, Korea. The study area is located in the western part of the stock-type Sancheong anorthosite complex. We performed a detailed fieldwork on the Sancheong anorthosite (SA) and Fe-Ti ore body (FTO) which constitute the Sancheong anorthosite complex, and reinterpreted the origin of FTO foliation and the genetic relationship between them from the foliations, shear zones, occurrences of the SA and FTO. The new structural characteristics between them are as follows: the multilayer structures of FTO, the derived veins of straight, anastomosing uneven types and block structures related to the size reduction of SA, the gradual or irregular boundaries of SA blocks and FTO showing bulbous lobate margins and comb structures, the FTO foliation and linear arrangements of flow occurrence which is not ductile shear deformation, the discontinuous shear zone of SA, the orientation of FTO foliations parallel to the boundaries of SA blocks, the predominance of FTO foliations toward the boundaries of SA blocks and being proportional to the aspect ratio of plagioclase xenocrysts and SA xenoblocks, and the flow folding structures of FTO foliation. Such field evidences indicate that the SA is not fully congealed when the FTO is melt and the fracturing of partly congealed SA causes the derived veins of FTO and the size reduction of SA. Also the gradual or irregular boundaries of SA blocks and FTO result from the mutual reaction between the not fully congealed SA blocks and the FTO melt, and the FTO foliation is a magmatic foliation which was formed by the interaction between the FTO melt and the partly congealed SA blocks. Therefore, these suggest that the SA and FTO are not formed from the intrusion of different magmas in genesis and age but from a coeval and cogenetic magma through multiple fractionation. We predict that the FTO will show an very irregular occurrence injected along irregular fractures, not the regular occurrence like as the intrusive vein and dike. It can be applied to the designing of Fe-Ti mineral resource exploration in this area.

• Journal of the Korean earth science society
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• v.22 no.6
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• pp.528-547
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• 2001

The blastoporphyritic granite gneiss (BPGN) including much alkali-feldspar megacrysts occurs in Jiri mountains area, southwestern part of Sobaegsan massif, Korea. The BPGN is formed gneiss complexes with other gneisses in Precambrian. The BPGN was named as porphyroblastic gneiss with porphyroblasts of alkali-feldspar megacrysts by other researchers, but the BPGN includes of euhedral alkali-feldspars (microcline), and the boundary with the granitic gneiss represents sharp contact as intrusive relationship. The BPGN mainly composes of alkali-feldspar megacrysts, quartz, plagioclase, K-feldspar and biotite some almandine and accessary minerals are muscovite, chlorite, apatite, zircon and opaques. The alkali-feldspar is microcline with perthitic texture. An content of plagioclases show 30 to 40. Biotites occur two type, one is Brown biotite which shows compositional ranges of Mg/Fe+Mg ratios from 0.38 to 0.52, the other is Green Bt. which is retrograde product. Camels to be various sizes and shapes have composition of almandine with 73 to 80 mole percent, but represent retrogressive zoning from core (X$_{pyr}$: 15.9${\sim}$20.8) to rim (X$_{pyr}$:13.7${\sim}$15.9) to be evidence of retrograde metamorphism. Megacrysts of alkali-feldspar in the BPGN show rectangular shape of euhedral and some become ellipsoidal or spheroidal in shape and the average size up to 20 cm long. The megacryst includes of biotite, plagioclase and quartz, and rarely euhedral apatite as inclusions. In petrochemistry the BPGN represents granodiorite composition, characteristics of peraluminous S-type granitoid and calc-alkaline features.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.326-335
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• 2007

This study was conducted to assess the environmental risks of anthracnose resistant transgenic chili peppers with the PepEST gene on non-target organisms in the agroecosystem environments during the chili pepper growing seasons in 2006. We quantitatively collected arthropods assemblages living on leaves and flowers of chili peppers on June 20, July 25, and August 25 by using an insect vacuum collector to compare the patterns of arthropod community structures between non-transgenic chili peppers (nTR, WT512) and anthracnose resistant transgenic chili peppers (TR, line 68). We found the seasonal difference with the highest species richness and Shannon's diversity in July's sampling among the growing seasons (P<0.05) and each sampling season showed the different arthropod community composition. We also found there was no statistical difference between the two types of crops, nTR and TR, at each sampling time (P>0.05). The significance level of arthropod community showed that there were lots of seasonal difference of functional groups as well as taxa but only the herbivore group in the functional groups was significantly different for the types of plants (P<0.05). So, we further examined the herbivore groups to find any potential damage and identified the possibility of herbivorous damage from some herbivores, grasshoppers, aphids and thrips. Although we couldn't find any adverse effects from the environmental risk assessment between the arthropod community structures on two types of plants from our results, we should keep working for the environmental risk assessment because of the herbivorous potential risk possibility.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.409-422
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• 2022

Two dominant thrips in hot pepper (Capsicum annuum) cultivating in greenhouses are Frankliniella occidentalis and F. intonsa in Korea. This study investigated their overwintering physiology. These two thrips were freeze-susceptible and suppressed the body freezing temperature by lowering supercooling point (SCP) down to -15~-27℃. However, these SCPs varied among species and developmental stages. SCPs of F. occidentalis were -25.7±0.5℃ for adults, -17.2±0.3℃ for pupae, and -15.0±0.4℃ for larvae. SCPs of F. intonsa were -24.0±1.0℃ for adults, -27.0±0.5℃ for pupae, -17.2±0.8℃ for larvae. Cold injuries of both species occurred at low temperature treatments above SCPs. Thrips mortality increased as the treatment temperature decreased and its exposure period increased. F. occidentalis exhibited higher cold tolerance than F. intonsa. In both species, adults were more cold-tolerant than larvae. Two thrips species exhibited a rapid cold hardening because a pre-exposure to 0℃ for 2 h significantly enhanced the cold tolerance to a lethal cold temperature treatment at -10℃ for 2 h. In addition, a sequential exposure of the thrips to decreasing temperatures made them to be acclimated to low temperatures. To investigate the overwintering sites of the two species, winter monitoring of the thrips was performed at the greenhouses. During winter season (November~February), adults of the two species were not captured in outside of the greenhouses. However, F. occidentalis adults were captured to the traps and observed in weeds within the greenhouses. F. occidentalis adults were also emerged from soil samples obtained from the greenhouses during the winter season. F. intonsa adults did not come out from the soil samples at November and December, but emerged from the soil samples obtained after January. To determine the adult emergence due to diapause development, two thrips species were reared under different photoperiods. Adult development occurred in all photoperiod treatments in F. occidentalis, but did not in F. intonsa especially under short periods. Tomato spotted wilt virus, which is transmitted by these two species, was detected in the weeds infested by the thrips during the winter season. These results suggest that F. occidentalis develops on weeds in the greenhouses while F. intonsa undergoes a diapause in the soil during winter.