• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.601-615
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• 2013

This study was conducted to compare the community structure and biodiversity of arthropods between conventional and organic red pepper fields. A total of 36 species of 24 families belonging to 10 orders from collected 28,718 arthropods; 6,901 individuals from conventional field and 21,871 individuals from organic field. A number of species comprising arthropod community was same in both fields as 32 species. Species richness of Diptera was the highest in conventional field and that of Hymenoptera and Colembolla was the highest in organic field. Abundance of Frankliniella intonsa was the highest regardless of farming method. Helicoverpa assulta was dominant in conventional field, and Homidia mediaseta, Diptera sp. 4 and Pardosa astrigera were dominant in organic field. Diversity of community on the ground was higher in organic field and statistically different. Similarity of arthropod community showed difference with 34.07% on the ground and 26.95% in the plant above ground. In the ecologically functional guild: species richness of general, pest and parasitoid of natural enemy groups in the plant above ground were statistically different and pest and parasitoid groups were higher in organic field, abundance of predator group of natural enemy on the ground was 2 times higher in organic field and statistically different and diversity of general and parasitoid groups in the plant above ground were statistically different. In the relative occupancy rate, pest group was the highest in conventional field and decomposer group was the highest in organic field. The results of present study is considered to provide useful information of arthropod community for developing efficient insect pest management in organic farming.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.92-95
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• 2016

The black soldier fly is economically important because its prepupae are used as feed for many animals, including fish and swine. In Korea, black-soldier-fly farms have attempted to increase annual breeding and mass egg production for use in animal feed, as well as the decomposition of organic waste. Such efforts require an understanding of optimal mating and oviposition techniques. Specifically, adult densities and cage size may both improve the efficiency of mass egg production. Our study used four sizes of nylon cages ($1.0{\times}1.0{\times}2.5m$, $1.5{\times}1.5{\times}2.5m$, $2.0{\times}2.0{\times}2.5m$, $2.5{\times}2.5{\times}2.5m$) and three density treatments (4 kg, 8 kg, and 10 kg of pupae) to investigate optimal habitat size and adult density. We found that cage size (independent of density) did not significantly influence female fecundity (number of egg clutches and egg weight), whereas higher densities increased egg number and weight regardless of cage size. Thus, we recommend manipulating adult density to enhance productivity in commercial black-soldier-fly farming. However, we also propose further detailed research to develop methods that account for seasonal changes and environmental conditions, as climatic variables (temperature, sunlight) likely influence female fecundity as well.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.417-422
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• 2021

This study aimed to provide information on the biodiversity of various arthropods living in paddy fields during the winter season by examining their incidence density. Insect collection was carried out by 50 × 50 cm grids of soil surface and plants from paddy fields, as well as from ridges between paddies, using a battery-powered aspirator. The total number of individuals collected from paddy fields and inter-paddy ridges was 41,197, most of belonged to the orders Collembola, Hemiptera, and Diptera. Arthropods showed similar appearance patterns in fields under both organic and conventional farming. However, a higher number of insects was collected in organic farms. The species diversity, species richness, and species evenness were all greater in inter-paddy ridges than in paddy fields, in a statistically significant manner (P < 0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.1
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• pp.23-31
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• 2024

This study evaluated the utilization of a low fish meal (LFM) diet and black soldier fly (BSF) Hermetia illucens meal and oil as a fish meal (FM) substitute or functional additive for juvenile olive flounder Paralichthys olivaceus at the Jeju fish farm. Two experimental diets replaced FM using animal (tankage, poultry byproduct and tuna byproduct meal) and plant (wheat gluten and soy protein concentrate) protein sources, containing 45% (FM45) and 35% (FM35) of FM, respectively. One experimental diet replaced FM with animal, plant, and BSF meal, fish oil using insect meal and oil (FM35+). After the feeding trial ended, no differences in growth performance, feed utilization, survival and biological indices were observed among all experimental groups. Aspartate aminotransferase and cholesterol levels in the FM35 and FM35+ groups were significantly higher than that in the FM70 group. The linoleic acid level in the muscle was significantly higher in the fish fed with the FM70 diet than in those fed with the FM45, FM35, and FM35+ diets. Thus, the LFM diet is suitable for juvenile olive flounder farming during six months.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.75-86
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• 2008

Many kinds of environment friendly agricultural materials (EFAMs) were used for the plant protection, furthermore they support the growth of crops in the greenhouses and the kindly environment friendly farming. Natural enemies might be used for control of insect pest with EFAMs at the same space and time. For testing the toxicity of EFAMs against to natural enemies, 10 EFAMs were selected and tested in small greenhouses and farm's fields. In case of Harmonia axyridis larva, there was no predacious activity against cotton aphids in the block with EFAMMo L, EFAMPE D, EFAMME G and EFAMAE A, otherwise, aphid population was rapidly decreased in the control block without EFAMs. Both of Trialeurodes vaporariorum and Encarsia formosa population were slightly decreased in the block with EFAMs. There were significantly decreased in the block with IEFAM C, FEFAM D, EFAMSM Band EFAMPE D compared with control area. Especially, there was significantly maintained a very low population, both T. vaporariorum and E. formosa in the block with EFAMMo C. The parasitized ratio of Aphidius colemani is also very low in the block with EFAMs compared with control area. In the block with IEFAM C, FEFAM D, EFAMPE D and EFAMMo L, there were significantly different with control area in the number of mummies. Otherwise, in case of Diglyphus isaea and Liriomyza trifolii, there was no significantly different between blocks with and without EFAMs. In the block with EFAMMo C, Tetranychus urticae and Phytoseiulus persimilis populations were significantly maintained a very low level. However, the population of T. urticae was increased, but P. persimilis was decreased in the block with EFAMMo L.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.95-99
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• 2013

To investigate the actual condition of production and management of sod, a questionnaire was ask to 57 farmers in major cultivated areas of turf sod in Korea in 2010 and 2011. The results of the turfgrass management situation analysis showed a mixed farming where the ratio of the principal work and the side work progress similarly, and for the landholding type depending on the management scale, the rental ratio was high for a scale over 0.5 ha. Sod production farmers has high-profile in new varieties of turfgrass, integrated management of the fertilization and soil or disease and insect pest however the future of the turfgrass industry does not seem optimistic due to the problems such as market stability or scarcity of worker. Obtaining of information on culture methods depended neighbor's experience (81.8%). Concerning the varieties preference analysis, the 32.1% of farmer answered that the reproductive rate was a key factor for the new variety. Sod production farmers want to receive financial support (28.1%), improvement of distribution structure of sod (26.6%), and spread of good variety turfgrass (23.4%).

• Parasites, Hosts and Diseases
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• v.56 no.5
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• pp.437-446
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• 2018

To investigate the prevalence of Toxoplasma gondii in pork on the market in Korea, an in-house enzyme-linked immunosorbent assay for tissue fluid (CAU-tf-ELISA) was developed using a soluble extract of T. gondii RH strain tachyzoites. As the standard positive controls, the piglets were experimentally infected with T. gondii: Group A (1,000 cysts-containing bradyzoites), Group B (500 cysts-containing bradyzoites) and Group C ($1.0{\times}10^3$ or $1.0{\times}10^4$ tachyzoites). The CAU-tf-ELISA demonstrated infection intensity-dependent positivity toward tissue fluids with average cut-off value 0.15: 100% for Group A, 93.8% for Group B and 40.6% for Group C. When tissue-specific cut-off values 0.066-0.199 were applied, CAU-tf-ELISA showed 96.7% sensitivity, 100% specificity, 100% positive and 90.0% negative predictive values. When compared with the same tissue fluids, performance of CAU-tf-ELISA was better than that of a commercial ELISA kit. Of the 583 Korea domestic pork samples tested, anti-T. gondii antibodies were detected from 9.1% of whole samples and 37.9% from skirt meat highest among pork parts. In the 386 imported frozen pork samples, 1.8% (skirt meat and shoulder blade) were positive for anti-T. gondii antibodies. In Korea, prevalence of anti-T. gondii antibodies in the pork on retail markets appeared high, suggesting that regulations on pig farming and facilities are necessary to supply safe pork on the tables.

• Korean journal of applied entomology
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• v.59 no.1
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• pp.41-54
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• 2020

Two mosquito species were collected in still-water near farming area in Andong, Korea. Based on morphological characters, these two mosquitoes were identified as Aedes koreicus and Culex vagans, respectively. DNA barcode analyses supported the identification. An entomopathogenic bacterium, Bacillus thuringiensis subsp. israelensis (BtI), exhibited insecticidal activities against the two mosquito species and its virulence was more potent than that of B. thuringiensis subsp. kurstaki. It has been known that the bacterial metabolites of Xenorhabdus spp. suppress insect immunity and enhance pathogenicity of B. thuringiensis. This study tested the effect of the bacterial culture broth of Xenorhabdus spp. on enhancing BtI pathogenicity. Among three Xenorhabdus spp., culture broth of X. ehlersii (Xe) was relatively effective to enhance BtI pathogenicity against both mosquito species. Indeed, organic extracts of Xe culture broth suppressed the hemocyte-spreading behavior, suggesting the presence of immunosuppressant in the culture broth. These results suggest a formulation of BtPlus by mixing BtI spore and Xe culture broth to be applied to control the two mosquito species.

• Research in Plant Disease
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• v.17 no.2
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• pp.142-147
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• 2011

In order to develop a environmentally friendly control protocol for managing tomato leaf mold disease in the field, we employed bacteria- and fungi-based commercially available microbial preparations. The field experiment was conducted from April to July in 2010. Average incidence rates tomato leaf mold caused by Fulvia fulva were 13.1% at the two plastic houses located in Jangsung, Jeonnam area. Initially 11 microbial preparations were tested for antifungal activity against F. fulva in vitro. Among them, 7 selected preparations showed to be inhibited the mycelial growth of the fungal pathogen over 50%. Four microbes suppressed disease incidence as much 50% under greenhouse condition. Eventually in the field two microbial products including Bacillus subtilis GB-0365 and B. subtilis KB-401 respectively were showed control value up to 71.8% for four times sprays from 20 days to 70 days after transplanting. Furthermore, the control value of three times spray program demonstrated 79.3%. Efficacy of the three and four spray programs was more effective than that of non-spray control treatment. Our results indicated that adjustment of application method of commercially available microbial preparation could be used to control a target plant disease as an effective and efficient crop protection system for organic farming.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.627-636
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• 2023

Bemisia tabaci Gennadius, one of the most invasive insect pests, has spread quickly nationwide since it was introduced to South Korea in 2008. The use of insecticides is the main management strategy for this pest, but the control efficiency has been decreased due to insecticide resistance. We collected 12 local B. tabaci populations to investigate the regional differences in efficiency and observed the mortality from 14 commercial insecticides applied at recommended concentrations (RC) and dilutions (0.1 RC and 0.01 RC) using the leaf dipping bioassay. Except for etofenprox (46-64%), thiamethoxam (37-60%), pyriproxyfen (21-61%), and pyridaben (61-65%), the other insecticides showed excellent insecticidal efficacy of 70% to 100% at their RC. In particular, flupyradifurone, emamectin benzoate, and cyantraniliprole showed high insecticidal efficacy of over 90% in all of the tested populations. Some insecticides that rapidly decreased in activity (less than 30%) at diluted concentrations or showed high resistance levels in nearby regions were classified for cautious use due to the possibility or potential to develop resistance. The results provide selected insecticides for B. tabaci control by region and could contribute to reducing insecticide abuse and increasing insecticidal efficiency in farming fields.