• Korean journal of applied entomology
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• v.22 no.2 s.55
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• pp.52-66
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• 1983

The brown planthopper, N. lugens (Stal), has become a serious pest of rice in tropical Asia during the last decade. At high pest density, its feeding damage causes 'hopperburn' or complete wilting and drying of the rice plant. It also transmits grassy and ragged stunt virus diseases. The estimated losses caused by the pest in tropical Asia exceed $US\$300$ millions. While cultivation of resistant rice varieties has proved to be highly effective against the pest, their long-term stability is threatened because of the evolution of prolific biotypes which can destroy these varieties. At present, identification of biotypes is based principally on the differential reactions of host rice varieties to the pest and on host-mediated behavioral and physiological responses of the pest. Recent findings of morphological differences in adult rostrum, legs, and antennae, body parts that possess receptors for host plant location and discrimination, and cytological differences in N. lugens populations maintained as stock cultures strongly complement other biotype studies. So far, three N. lugens biotypes have been identified in the Philippines. Biotype I can survive on and damage varieties that do not carry and genes for resistance, while Biotype 2 survives on resistant varieties carrying Bph 1 gene and Biotype 3 on varieties carrying gene bph 2. However, none of these biotypes can survive on varieties with genes Bph 3 or bph 4. Several varieties which are resistant in the Philippines are susceptible in India and Sri Lanka as the South Asian biotypes of N. lugens are more virulent than Southeast Asian biotypes. To monitor the pest biotypes in different geographical regions and to identify new sources of resistance, an International Brown Planthopper Nursery has been established in many cooperating countries. The evolution of biotypes is an exceedingly complex process which is governed by the interactions of genetic and biological factors of the pest populations and the genetic makeup of the cultivated varieties. While the strategy for sequential release of varieties with major resistance genes has been fairly successful so far, the monegenic resistance of these varieties makes them vulnerable to the development of the pest biotypes. Therefore, present breeding endeavors envisage utilizing both major and minor resistance genes for effective control of the pest.

• Journal of applied mathematics & informatics
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• v.27 no.5_6
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• pp.1097-1107
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• 2009

In this paper, three species stage-structured predator-prey model with time delayed and periodic constant impulsive perturbations of predator at fixed times is proposed and investigated. We show that the conditions for the global attractivity of prey(pest)-extinction periodic solution and permanence of the system. Our model exhibits a new modelling method which is applied to investigate impulsive delay differential equations. Our results give some reasonable suggestions for pest management.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.211-219
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• 2022

Over the past decade, double-stranded RNA (dsRNA)-mediated gene silencing technology has progressed significantly for pest management in agriculture and for protecting beneficial insects from pathogens. Recently, breakthroughs in RNA interference (RNAi) applications for insect pest management by academia and commercial entities have provided RNAi products as commercial biopesticides. Although RNAi technology has vast potential and advantages for pest control, challenges, and limitations remain in practical applications. This review explores current challenges in the development of dsRNAs as a pest management tool and considers new approaches to overcome biological and environmental obstacles, such as poor stability and resistance.

• Korean journal of applied entomology
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• v.31 no.1
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• pp.69-78
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• 1992

The extensive cultivation of new yielding varieties might give some distruption to the rice insect pest complex in Korea The population of Nephottetix cincticeps and Laodelphax striatellus has decreased in number since the extensive cultivation of new varieties, Tongil lines, in 1976. During the last 23 years, the rice insect pest population except for Chilo suppressalis drastically decreased, however, C. suppressalis population increased again in recent years. This tendency seems to be very closely correlated with the cultivation of new varieties, and a lot of fertilizations and insecticides applications.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.329-333
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• 2019

A larval attack leading to severe loss to fruit production of Japanese plum (Prunus salicina Lindl.) was reported in the orchards in Gwangyang, Jeonnam province, South Korea during the spring seasons of 2018 and 2019. As the result of investigation, the damage was identified to be caused by Monocellicampa pruni Wei of the family Tenthredinidae. In this study, we present the first report of this pest in Korea and describe the damage caused by the larvae as well as taxonomic information by illustrating the characteristics of male genitalia.

• Korean journal of applied entomology
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• v.57 no.3
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• pp.161-164
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• 2018

Pristiphora (Pristiphora) apricoti Zinovjev, 1993, pest of Prunus armeniaca var. ansu Max, belonging to Nematinae of Tenthredinidae is newly recognized in South Korea. The host plant is recorded for the first time from South Korea. Diagnosis, rearing notes, and photographs of the diagnostic characters and oviposition are provided.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.796-808
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• 2018

The intracellular bacterium Wolbachia pipientis is widespread in arthropods. Recently, possibilities of novel Wolbachia-mediated hosts, their distribution, and natural rate have been anticipated, and the coconut leaf beetle Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae), which has garnered attention as a serious pest of palms, was subjected to this interrogation. By adopting Wolbachia surface protein (wsp) and multilocus sequence type (MLST) genotypic systems, we determined the Wolbachia infection density within host developmental stages, body parts, and tissues, and the results revealed that all the tested samples of B. longissima were infected with the same Wolbachia strain (wLog), suggesting complete vertical transmission. The MLST profile elucidated two new alleles (ftsZ-234 and coxA-266) that define a new sequence type (ST-483), which indicates the particular genotypic association of B. longissima and Wolbachia. The quantitative real-time PCR analysis revealed a higher infection density in the eggs and adult stage, followed by the abdomen and reproductive tissues, respectively. However, no significant differences were observed in the infection density between sexes. Moreover, the wsp and concatenated MLST alignment analysis of this study with other known Wolbachia-mediated arthropods revealed similar clustering with distinct monophyletic supergroup B. This is the first comprehensive report on the prevalence, infection dynamics, and phylogeny of the Wolbachia endosymbiont in B. longissima, which demonstrated that Wolbachia is ubiquitous across all developmental stages and distributed in the entire body of B. longissima. Understanding the Wolbachia infection dynamics would provide useful insight to build a framework for future investigations, understand its impacts on host physiology, and exploit it as a potential biocontrol agent.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.6
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• pp.591-601
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• 2020

After North Korea's sixth nuclear test, the operational environment on the Korean Peninsula has fundamentally changed, and the South Korean military faces various security challenges, including a reduction in military service resources and shorter military service periods. In particular, the South Korean military is seeking a new paradigm in military construction amid changes in the defense acquisition environment linked to the push for defense reform 2.0 and the utilization of the fourth industrial revolution. Therefore, this study considered strategies for improving the operational test and evaluation of weapons systems suitable for changes in the defense acquisition environment to effectively prepare for existing military threats and future warfare patterns. For this purpose, external environment analysis and internal capabilities were diagnosed using PEST Analysis and SPRO Analysis, and improvement strategies were derived through SWOT analysis.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.4
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• pp.771-780
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• 2024

In this study, we implemented a real-time pest detection and prediction system for a strawberry farm using a computer vision model based on the YOLOv5 architecture and an Isolation Forest Classifier. The model performance evaluation showed that the YOLOv5 model achieved a mean average precision (mAP 0.5) of 78.7%, an accuracy of 92.8%, a recall of 90.0%, and an F1-score of 76%, indicating high predictive performance. This system was designed to be applicable not only to strawberry farms but also to other crops and various environments. Based on data collected from a tomato farm, a new AI model was trained, resulting in a prediction accuracy of over 85% for major diseases such as late blight and yellow leaf curl virus. Compared to the previous model, this represented an improvement of more than 10% in prediction accuracy.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.77-79
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• 2003

Obolodiplosis robiniae (Haldeman, 1987) (Diptera: Cecidomyiidae), a pest species on a black locust tree, which was originally distributed in North America, is newly recorded from Korea. The specimens were collected from the central Korea. Morphological diagnoses of the both sexes and the symptoms on the host plants are provided.