• Journal of Apiculture
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• v.32 no.2
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• pp.119-131
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• 2017

For the Rapid detection of small hive beetle (SHB; Aethina tumida) and for the mass-survey against SHB invasion, SHB-specific ultra-rapid PCR system was developed. Three different pairs of Aethina tumida-specific primers were deduced from cytochrome oxidase subunit I (COI) gene in mitochondrial DNA of SHB. Using optimized SHB-specific ultra-rapid PCR, $2.1{\times}10^1$ molecules of COI gene belonged to SHB could be detected specifically and quantitatively within 18 minutes 40 seconds. For the purpose of the application in apiary field, a DNA extraction method from bee debris was separatedly developed. When $10^5$ SHB-specific COI molecules (1/1000 body of SHB larvae) are existed in 1g of bee debris, it could be verified inner 10 minutes as qualitative and quantitative manner. SHB-specific ultra-rapid PCR we proposed would be expected to apply widely, either in apiary field or laboratory, for the rapid detections and the control against SHB-invasion.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.554-562
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• 2020

Tremex fuscicornis (Siricidae), known as the xylophagous horntail, and Leucospis japonica (Leucospidae), known as the parasitoid wasp, are wood-boring wasps belonging to the order Hymenoptera. These insects are interesting sources of biological inspiration for the development of drilling mechanisms. To study the biomimicry aspects, the morphological characters of the ovipositor of T. fuscicornis and L. japonica were analyzed using a stereoscopic microscope, a field emission scanning electron microscope, and an optical microscope. There were many differences in the ovipositors between the two species, such as shape, length, surface structure, and arrangement of the teeth. Evenly arranged teeth were developed at the tip of both the dorsal valve and the ventral valve of the ovipositor of T. fuscicornis and looked like a rotating drill bit. In contrast, in L. japonica, the teeth, which looked like a saw, were found only on the ventral valve. Moreover, the tip of the ovipositor of T. fuscicornis was symmetrically divided into four parts, while that of L. japonica was divided into three parts having a 2:1:1 ratio. However, in the case of T. fuscicornis, after the 14th tooth, four parts melded into three parts maintaining a 2:1:1 ratio, and a dovetail joint was found on the horizontal cross-section of the ovipositor that allowed vertical movement for making a hole. These morphological differences of the ovipositor may be due to the insects' lifestyles and phylogenetic distance. Finally, zinc was commonly found at the tip of the ovipositors of both species, a probable result of ecological adaptation created by drilling wood.

• Research in Plant Disease
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• v.27 no.2
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• pp.61-65
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• 2021

Root-knot disease caused by Meloidogyne incognita is major soil pathogen and cause severe economic damages to vegetable crops. In this study, we selected rhizobacteria for biocontrol of the root-knot nematode, M. incognita, and identified; performed bioassay of the bacterial extracts in cucumber seedlings. The crude extracts of strains CT16 and JC05 out of 180 strains inhibited egg hatching and increased juvenile mortality in vitro assay; based on 16S rRNA sequences analysis, the two strains were identified as Bacillus sp. CT16, and Neobacillus sp. JC05. After extracting the bacterial supernatants by using various organic solvents, n-butanol and n-hexane extracts of strain CT16 and n-butanol extract of strain JC05 showed inhibitory activity of egg hatching depending on concentrations. Subsequently, n-butanol extracts of two strains significantly suppressed formation of egg masses in cucumber seedling. Therefore, these results indicated that strains CT16 and JC05 could be used as potential biocontrol agents against M. incognita.

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.277-284
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• 2021

This study surveyed the ecological characteristics of Squalidus gracilis majimae at Nakdong River tributary Sinan Stream from January to December 2020. The species inhabited the riverbed that was mostly covered with gravel and sand. The water depth was 27-158 cm, and the average was rather deep at 54 cm. The stream velocity was slow at 0.41±0.19 (0.24-0.86) m/sec. The gender ratio of females to males was 1:0.73. According to the total length-frequency distribution, the age indicated that the group with less than 50 mm in total length was one year old, the group with 70-69 mm was two years old, and the group over 70 mm was three years old. The total length of sexually mature fishes was 50 mm for females and 60 mm for males. The spawning season was from June to July, and the water temperature was 20.9-23.4℃ during the period. The prosperous spawning season was July. The average number of eggs in the ovaries was 1,009 (595-1,630) per matured female, and the matured eggs were yellowish and spherical with a mean diameter of 0.78±0.08 (0.57-0.83) mm. The live foods were S. gracilis majimae Protozoa, attached algae, zooplankton, and aquatic insects. The feeding habits of S. gracilis majimae are omnivorous, but more than 80% of the stomach content was aquatic insects, Chironomidae spp. The larger the size of this species, the greater the amount and frequency of eating aquatic insects, which are animal feeds. The population that ate aquatic insects did not eat vegetable food.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.4
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• pp.356-363
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• 2020

The distribution of ticks and severe fever with thrombocytopenia syndrome virus (SFTSV) pathogens were investigated by collecting ticks from March to November 2018 in four environments (grass fields, copses, mountain roads, and tombs) in Jeju. Three thousand and ninety ticks were collected using a tick trap, and 1,569 ticks were collected using the flagging method. Of the 4,659 ticks collected, Haemaphysalis longicornis and Haemaphysalis flava accounted for 4,440 ticks (95.2%) and 219 ticks (4.7%), respectively. Nine hundred and fifty, 883, 847, and 410 ticks were collected from grass fields, copses, mountain roads, and tombs, respectively, using tick traps, whereas 704, 472, 197, and 196 ticks were collected from copses, mountain roads, tombs, and grass fields, respectively, using the flagging method. The largest fraction of ticks (2,978) was collected from April to August, and most were collected in May and June. Adult ticks comprised 94 percent of the total ticks from June to August. SFTSV was not detected in the 4,440 H. longicornis ticks or the 219 H. flava ticks collected in this study.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.433-441
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• 2020

This study was conducted to understand the distribution characteristics of aquatic insects in ecologically different ponds in terms of the disruption. We investigated the fauna of aquatic insects in three artificial ponds (pond 1, 2 and 3) and two natural ponds (pond 4 and 5) located within 1 km each other around Gungdaeoreum in Jeju Island, from March 2018 to June 2020. A total of 50 species belonging to 15 families were found in the surveyed ponds: total 850 individuals with 14 species in 4 families of the order Odonata, total 4,391 individuals with 14 species in 6 families of the order Hemiptera, and total 2,014 individuals with 22 species in 4 families of the order Coleoptera. In overall, total abundance and species numbers were relatively higher than those of artificial pond in natural ponds in which animal and plant ecosystems were well established. In the case of artificial ponds, the number of individuals and species recovered rapidly when reconstituted by introducing aquatic plants, etc. (Pond 1). The nymphs of Odonata were observed largely in ponds without natural enemies such as large fish, and where adults could freely access without interception by artificial structure. Phytophagous Corixidae of the order Hemiptera were abundant, and Haliplidae populations of the order Coleoptera were affected by the distribution of the plants. Accordingly, the major factors affecting aquatic insect abundance were identified as the presence of refuges such as the topography and aquatic plants and presence of predators. Species of the order, Odonata were vulnerable based on these factors. Our results can be useful as basic information for the restoration of wetlands and construction of artificial wetlands or for conservation of species diversity in the future.

• Journal of Life Science
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• v.32 no.6
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• pp.455-462
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• 2022

This study examined changes in the body composition of Protaetia brevitarsis larvae fed sulfur and selenium. Among the general chemical components, an increase in protein was observed in the sulfur-fed group, whereas an increase in fatty acid was found in the groups fed selenium and sulfur/selenium. The structural amino acid showed some tendency to be increased compared to the control group, but this was especially true in the sulfur-fed group. The free amino acid were increased in the groups fed selenium and sulfur/selenium, with GABA, Glu, and Pro, in particular, being increased in the group fed sulfur/selenium. Among the essential amino acids, Met, Trp, and Val tended to be increased in selenium and sulfur/selenium groups. Saturated and polyunsaturated fatty acids showed a tendency to increase in the group fed sulfur/selenium, but monounsaturated fatty acid tended to be decreased in the group. In particular, no oleic acid was detected in the sulfur/selenium group, whereas palmitic acid, palmitoleic acid, and linoleic acid were increased. From observations of these body composition changes associated with the feeding of sulfur and selenium, it is estimated that the group fed sulfur/selenium would likely undergo a pronounced change in body composition. Therefore, we suggest that it is possible to manufacture a food that has enhanced functionality by appropriately adjusting the diet of Protaetia brevitarsis larvae.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.143-154
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• 2022

Plant secondary metabolites play an important role in insect-plant interactions. Herbivorous insects have various strategies to cope with the plant defensive compounds. Polyphagous insects feed on a wide variety of plant species, and their detoxification mechanisms are more complex since they tend to respond to a large array of different plant-derived chemicals. Alternatively, oligophagous insects specialize on only a few related plant species and may be expected to have a more efficient form of adaptation. This adaptation could involve either the production of large quantities of enzymes to detoxify their defensive compounds or the sequestration of the compounds or their metabolites. The oriental tobacco budworm, Helicoverpa assulta, is a specialist herbivore, feeding on a few plants of Solanaceae, such as tobacco and hot pepper. Understanding its host-plant adaptation not provides an important insight on physiology, ecology and evolution of specialist herbivores, but also gives a clue to develop management strategies of the pest species such as H. assulta. This paper briefly reviews the specialist, H. assulta, focusing on its host range, larval associations with the host plants, and detoxification mechanisms to nicotine and capsaicin, two characteristic defensive compounds derived from its two major host plants, tobacco and hot pepper, respectively. It summarizes the relevant research over the last half century and provides a future perspective on this subject.

• Journal of the Korean Geosynthetics Society
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• v.21 no.4
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• pp.55-67
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• 2022

In this paper, fundamentals and recent development of the interferometric synthetic aperture radar, known as InSAR, technique for measuring ground deformation through satellite image analysis are presented together with case histories illustrating its applicability to urban ground deformation monitoring. A study area in Korea was selected and processed based on the muti-temporal time series InSAR analysis, namely SBAS (Small Baseline Subset)-InSAR and PS (Persistent Scatterers)-InSAR using Sentinel-1A SAR images acquired from the year 2014 onward available from European Space Agency Copernicus Program. The ground settlement of the study area for the temporal window of 2014-2022 was evaluated from the viewpoint of the applicability of the InSAR technique for urban infrastructure settlement monitoring. The results indicated that the InSAR technique can reasonably monitor long-term settlement of the study area in millimetric scale, and that the time series InSAR technique can effectively measure ground settlement that occurs over a long period of time as the SAR satellite provides images of the Korean Peninsula at regular time intervals while orbiting the earth. It is expected that the InSAR technique based on higher resolution SAR images with small temporal baseline can be a viable alternative to the traditional ground borne monitoring method for ground deformation monitoring in the 4^th industrial era.

• Journal of Korea Water Resources Association
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• v.55 no.spc1
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• pp.1235-1249
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• 2022

This study applied the web crawling technique for extracting big data news on water quality accidents in the water supply system and presented the algorithm in a procedural way to obtain accurate water quality accident news. In addition, in the case of a large-scale water quality accident, development patterns such as accident recognition, accident spread, accident response, and accident resolution appear according to the occurrence of an accident. That is, the analysis of the development of water quality accidents through key keywords and sentiment analysis for each stage was carried out in detail based on case studies, and the meanings were analyzed and derived. The proposed methodology was applied to the larval accident period of Incheon Metropolitan City in 2020 and analyzed. As a result, in a situation where the disclosure of information that directly affects consumers, such as water quality accidents, is restricted, the tone of news articles and media reports about water quality accidents with long-term damage in the event of an accident and the degree of consumer pride clearly change over time. could check This suggests the need to prepare consumer-centered policies to increase consumer positivity, although rapid restoration of facilities is very important for the development of water quality accidents from the supplier's point of view.