• The Korean Journal of Soil Zoology
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• v.10 no.1_2
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• pp.55-64
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• 2005

Predatory nematodes are ubiquitous and feed on soil microorganisms including plant parasitic nematodes. They reduce populations of plant parasitic nematodes in virtually all soils because of their constant association with plant parasitic nematodes in the rhizosphere. Predatory potential of several species of predacious nematodes, belonging to the orders Mononchida, Diplogasterida, Dorylaimida and Aphelenchida, have been studied in detail on plant parasitic nematodes but most of the studies were based on in vitro experiments. A review of progress on the use of predatory nematodes as biological control agents of plant parasitic nematodes reveals that advocacy for predatory nematodes dates back to the early $20^{th}$ century; nevertheless, their potential has begun to be studied in recent years. Information on the efficacy of predatory nematodes under field conditions is lacking; however, some predatory nematodes have given very promising results against plant parasitic nematodes. This article summarizes research progress to date on predatory nematodes and discusses about their possible use in the management of plant parasitic nematodes.

• Journal of Contemporary Eastern Asia
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• v.21 no.1
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• pp.53-71
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• 2022

The overall purposes of this study are to identify actions taken to counter predatory publishing practices as well as to propose an ICT-based model to detect such practices. The need to raise quantitative performance metrics to support career goals has created immense pressure on researchers to publish in the literature as frequently as possible. This "publish or perish" syndrome appears to be fueling a rise in scholarly journals and conferences that provide quicker and easier routes to publication. However, such avenues sometimes involve questionable academic practices with important ethical ramifications. One notable example is the proliferation of predatory publishing, including predatory journals and fake conferences. The widening impact of such activities is beginning to prompt academic societies, publishers, and institutions to take measures. This paper discusses the issues on predatory publishing practices, and some of the actions taken by various stakeholders to address these practices. In order to build a transparent and sustainable scholarly publishing ecosystem, this study highlights multi-dimensional and specific solutions, including reforms to research ethics codes, research management rules, and legal protection from exploitative practices. This paper proposes an ICT-based cooperative model for monitoring of predatory publishers as a potential solution to create a sustainable and transparent infrastructure for a scholarly publication system guarding against misconduct in publishing practices.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.173-180
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• 2001

The stink bug, Eocanthecona furcellata (Wolff.) is a natural and potential biocontrol agent of Spilarctia obliqua (Walk.). The present investigation reveals the biology, predatory efficiency and reproductive parameters of the predator which feeds on S. obliqua caterpillars in mulberry plantation. In order to find out the role of prey sine on the biology of the predators the predatory insects were separately fed with small and large caterpillars of S. obliqua. The incubation period of the eggs of E. furcellata was 8.37${\pm}$0.44 days, while the nymphal duration varied as per the prey sine. The predator when supplied with small larvae of prey, consumed 61.1 larvae and completed nymphal stage in 19.9 days; while those fed with larger prey, consumed 36.1 larvae and completed their nymphal stage in 21.55 days. The prey size also influences the reproductive parameters of the predator, The adult female predator is more voracious feeder than the adult male and consumed 41.9${\pm}$0.64 small larvae and 42.2${\pm}$0.87 large larvae during their life span. The longevity of male and female was observed as 20.7 and 29.4 days respectively. Visualization of the predator as well as the movement of the prey increases the predatory efficiency. Scanning electron microscopic studies on the feeding part explain its support in effective predation. Field observations indicated a drastic fall in the incidence of the mulberry pest, S. obliqua with the increased population E. furcellata in mulberry plantation.

• Korean Journal of Organic Agriculture
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• v.14 no.3
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• pp.315-323
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• 2006

The potential of the predatory mite Phytoseiulus persimilis (Acarina : Phytoseiidae) to control two spotted spider mite Tetranychus urticae (Acarina : Tetranychidae) was investigated on sustainable strawberry fields in Jeonnam area. The density of T. urticae increased from 4th and 7th weeks after single and two timings release P. persimilis, respectively. On the three timings of release plot, number(density) of T. urticae on a leaf maintained fewer than 10 during the 15 weeks after release. In the 1,000 release of P. persimilis per $100m^2$ plot, P. persimilis could not suppress T. urticae. In the 2,000 release plot, P. persimilis could suppress T. urticae with low density which was the similar in the 3,000 release plot. Two-spotted spider mite, T. urticae, occurred from late March and increased density in Hampyeong area. In the P. persimilis released field, T. urticae inhibited continuously after release. In Boseong area, density of P. persimilis increased 50 per 10 leaves through increasing of T. urticae. Percent of occurrence of T. urticae showed high $10.5{\sim}75.5%$ in none-release predatory mite but not high in release treatment. T. urticae on sustainable strawberry field could be inhibited by P. persimilis.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.272-279
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• 2015

The aim of this study was to assess the interaction between Daphnia similis and various organisms related to the rice paddy ecosystem. We selected several organisms that are likely to prey on D. similis and evaluate predation rate as well as responses of D. similis to the chemical compounds exuded by these organisms. As a result of predation experiment, larval dragonfly (Anax parthenope) and Triops longicaudatus were clearly shown decreasing abundances of D. similis. Especially, Triops longicaudatus was observed higher feeding rates on D. similis than larval dragonfly. Chemical compounds from the vertebrates such as fish (Misgurnus anguillicaudatus, Pseudorasbora parva, Micropterus salmoides) and tadpole of frog (Rana nigromaculata) did not affect the life history of Daphnia. However, a potential predatory fish P. parva induced significantly longer tail spine in Daphnia. In addition, among the invertebrates (T. longicaudatus, A. Parthenope, Micronecta spp., Palaemon paucidens), chemical compounds exuded by T. longicaudatus induced shorter body and significantly longer tail spine in D. similis.

• Ecology and Resilient Infrastructure
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• v.10 no.1
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• pp.11-19
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• 2023

Alien species are known to threaten regional biodiversity globally, which has increased global interest regarding introduction of alien species. The Ministry of Environment of Korea designated species that have not yet been introduced into the country with potential threat as alert alien species to prevent damage to the ecosystem. In this study, potential habitats of Esox lucius and Maccullochella peelii, which are predatory and designated as alert alien fish, were predicted on a national basis. Habitat suitability was evaluated using EHSM (Ecological Habitat Suitability Model), and water temperature data were input to calculate Physiological Habitat Suitability (PHS). The prediction results have shown that PHS of the two fishes were mainly controlled by heat or cold stress, which resulted in biased habitat distribution. E. lucius was predicted to prefer the basins at high latitudes (Han and Geum River), while M. peelii preferred metropolitan areas. Through these differences, it was expected that the invasion pattern of each alien fish can be different due to thermal preference. Further studies are required to enhance the model's predictive power, and future predictions under climate change scenarios are required to aid establishing sustainable management plans.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.25-32
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• 2024

Frankliniella occidentalis and Thrips palmi are economically important pests of cucumber. The chemicals used to control them can be effective; however, they should not be used frequently on cucumbers that are consumed raw. Banker plants were selected to increase the control efficiency of Orius laevigatus, a natural enemy that can replace the chemicals. The hatching rate, emergence rate, nymph developmental period, survival rate, and reproductive capacity (fecundity and oviposition period) of O. laevigatus for four plants (moss rose, basil, broad bean, and cucumber) were investigated. The density of O. laevigatus on two selected banker plants was investigated in a cucumber greenhouse. The hatching rate of O. laevigatus eggs was highest at 92% in moss rose; however, there was no significant difference in survival rates between moss rose and basil. The fecundity and oviposition period of O. laevigatus were better in moss rose than in basil, with no significant difference between them. The flowering period of basil was longer than that of moss rose, from April to September. Therefore, basil has potential value as a banker plant for O. laevigatus and is expected to increase the biological control effect of O. laevigatus.

• Korean journal of applied entomology
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• v.39 no.4
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• pp.251-258
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• 2000

These studies were conducted to investigate the prey consumption and suppression of cotton aphid and green peach aphid by Chrysopa pallens Ramber as a predator. The 3$^{rd}$ instar of C. pallets fed on 29.8, 77.9, 133.6, and 155.7 individuals of apterous Aphis goussypii Glover a day at 17,22, 27, and 32$^{\circ}C$, respectively. A preovipositing female fed on 73.1 individuals, ovipositing female on 86.6 individuals, and adult male on 69.7 individuals of apterous Myzus persicae (Sulzer) a day at the 27$^{\circ}C$. The functional response curve of the larvae and adults of C. pallens to the densities of A. gossypii indicated Helling’s Type II: the consumption of prey by the C. pallens increased with the prey density but the consumption rate decreased. The attack rate of 3rd instar of C. pallens was the highest among the 2nd instar, 3$^{rd}$ instar, adult male and adult female, and handling time was the shortest. The critical ratio of the predator vs. the prey to effectively suppress the population of A. gossypii by releasing C. pallets eggs was 1 : 4 on red pepper and egg plant, and 1 : 3 on cucumber. Release of second larval stave of C. pallens at the ratio of 1 : 30 of the predator vs. the prey controlled satisfactorily A. gossypii on red pepper, and 1 : 20 on cucumber and tomato. The three-times introduction of the eggs of C. pallens was as effective as four applications of insecticides from mid-June to late September.r.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.173-178
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• 2011

BACKGROUND: Starfish is one of major sea invertebrates that have become a serious economic threat to aquacultural farms in Korea. Much effort has sacrificed to reduce the economic losses of the farms by predatory starfish, including developing and searching biological resources for medicinal and agricultural purposes. In the present study, we investigated aphicidal activity of the extracts from the starfish Asterina pectinifera against green peach aphid. METHODS AND RESULTS: Fresh starfishes were cut into small pieces, homogenized and soaked in methanol. The methanol extracts were centrifuged and the resulting supernatant was subjected to aphicidal activity assays and a series of silica gel column chromatography. More than 70% mortality of aphids were observed by the extracts at a concentration of 1,000 mg/L, exhibiting dose-dependent mortality. TOF-MS analyses detected polyhydroxysteroid as a main aphicidal compound from the starfish extracts. Transmission electronic microscopy could demonstrate that the extracts with polyhydroxysteroid caused aphids death by affecting their epicuticular membrane. CONCLUSION(s): This is the first report of aphicidal activity of the starfish Asterina pectinifera extracts against green peach aphid. Starfish biological resources may be used as a potential candidate for developing a new type natural insecticide.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.2
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• pp.129-153
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• 2017

Fair Competition policy in aviation field has been discussed since open skies policy began in 1970s. This issue has been also the main topic in the ICAO's Worldwide Air Transport Conference, the Air Transport Symposium, etc. ICAO defines competition as the existent or potential rivalry between two or more operators, carriers or groups, striving for advantages in the same market based on different prices, qualities and services. In a broader sense, the definition includes more various meanings; reasonable, fair, effective, and unrestricted competitions. Nowadays, competition laws and regulations to air transportation have been applied more frequently and the issues varies from antitrust immunity, mergers and alliances, abuse of dominant positions, capacity dumping and predatory pricing, sales and marketing, to airport charges and fees, state aid and loan guarantees. Now, the competition among the airlines or nations in aviation industry is changing to cooperation level. A lot of airlines try to survive by various cooperation methods. Therefore the policy of Korean aviation industry should be developed, taking so-called "the viewpoint of national aviation industry ecosystem" into consideration and Korean government should prepare a policy of fair competition to cope with it. First, in the process of open skies policy with neighboring countries such as China, Japan and the Middle East, it is necessary to apply the fair competition act and prepare laws and regulations to implement it. Second, the standards of effective ownership and control of air transportation business should be reviewed. Third, in preparation for aviation agreements and liberalization, the Korean aviation industry needs to study and review competition and cooperation issues through the analysis of strict aviation market structure for airlines and airport operations. Fourth, it is necessary to create a fair air transportation environment for the development of air transportation and competitiveness through preemptive policies such as the approval of mergers, acquisitions, JV and the ripple effects analysis.