• Korean journal of applied entomology
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• v.32 no.3
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• pp.317-322
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• 1993

Morphological investigations of the abdominal lateral lobes in females and the unguitractor p plates in the tarsi of legs in male and female N. lugens among the three Korean N. lugeηs bio-types revealed that the three biotypes varied from one another. The presence of a distinct ‘cut’ on the lateral lobes in brachypterous females distinguished Biotype 2 from Biotypes 1 and 3. The highest frequency of inserted unguitractor plates in fore-and mid-tarsal segments was exhibited by Biotype 2 in both sexes of each morphs.

• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.21-24
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• 2010

In recent years, many agricultural scientists are studying on eco-friendly farming methods. Among of lots of the methods, the natural insecticides are highly motivated and interested due to their safety and biodegradable issues, and readily available source of bioinsecticides. In this study, the crude extract of custard apple (Annona reticulata L.) seed and its three fractions which were separated based on polarity indexes were examined for their insecticidal activities against Myzus persicae Sulzer and Nilaparvata lugens S.. The crude extract (Aceton/MeOH) showed strong insecticidal activities against both insects at 3.00 mg/mL ($LD_{50}$=0.45mg/mL for M. persicae S. and 1.42 mg/mL for N. lugens S.). Furthermore, simple fractionation with hexane, chloroform, and water lead to increase three-folds insecticidal activity on chloroform fraction ($LD_{50}$=0.13mg/mL for M. persicae S. and 1.14 mg/mL for N. lugens S.). The results suggest that A. reticulata extracts might be used to control for M. persicae effectively.

• Journal of Life Science
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• v.22 no.12
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• pp.1614-1620
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• 2012

Transgenic rice plants with increased resistance to rice brown planthopper (Nilaparvata lugens St${\aa}$l) were generated by particle bombardment-mediated transformation of plants with a gene encoding snowdrop lectin (Galanthus nivalis agglutinin; GNA) under control of the rice Rubisco small subunit (rbcS) promoter.. A large number of transgenic rice plants containing the GNA gene were generated. The integration, expression, and inheritance of this gene in the $R_1$ and $R_2$ generations were demonstrated by Southern and western blot analyses. The plants contained one to five copies of the transgene. The GNA protein comprised approximately 0.01-2.0% of total soluble protein in the $R_1$ and $R_2$ transgenic plants. Insect bioassays and feeding studies showed that the GNA protein expressed in the $R_2$ transgenic rice plants reduced the survival of brown planthoppers. The introduction of GNA into rice plants therefore can help to control insect pests.

• Korean journal of applied entomology
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• v.56 no.4
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• pp.377-385
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• 2017

Estimates of evolutionary sequence divergence and inference of a phylogenetic tree for eight delphacid planthopper species were based on the full-length nucleotide sequence of the internal transcribed spacer 2 (ITS2) region. Size of the ITS2 DNA sequence varied from 550 bp in Sogatella furcifera to 699 bp in Nilaparvata muiri. Nucleotide sequence distance ($d{\pm}S.E.$) was lowest between N. muiri and N. bakeri ($0.001{\pm}0.001$), and highest between Ecdelphax cervina and Stenocranus matsumurai ($0.579{\pm}0.021$). Sequence distance between N. lugens and other planthoppers ranged from $0.056{\pm}0.008$ (N. muiri) to $0.548{\pm}0.021$ (S. matsumurai). In the neighbor-joining phylogenetic tree, all planthoppers were clustered separately into a species group, except N. muiri and N. bakeri. The ITS2 nucleotide sequence of N. lugens was used to design four loop-mediated isothermal amplification (LAMP) primer sets (BPH-38, BPH-38-1, BPH-207, and BPH-92) for N. lugens species-specific detection. After the LAMP reaction of three rice planthoppers, N. lugens, S. furcifera, and Laodelphax striatellus, with the four LAMP primer sets for 60 min at $65^{\circ}C$, LAMP products were observed in the genomic DNA of N. lugens only. In the BPH-92 LAMP primer set, the fluorescence relative to that of the negative control differed according to the amount of DNA (0.1 ng, 10 ng, and 100 ng) and incubation duration (20 min, 30 min, 40 min, and 60 min). At $65^{\circ}C$ incubation, the difference was clearly observed after 40 min with 10 ng and100 ng, but with a 60-min incubation period, the minimum DNA needed was 0.1 ng. However, there was little difference in fluorescence among all DNA amounts tested with 20 or 30 min incubations.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.79-83
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• 1985

Plant damages and yields of the different rice cultivars to brown planthopper (BPR), Nilaparvata lugens S., were observed for the evaluation of varietal resistance in paddy fields. Twenty nine Korean cultivas were transplanted in paddy fields with three plots of no insecticide, no insecticide and fungicide, and no fungicide at Haenam, southern coastal area in 1983. Among 6 varieties with BPR resistant genes, Samgang, Gaya, Hangangchal, and Cheongcheong showed very low populations of BPR and no damages on all treatments. Milyang 30 and Wonpung among them had considerable populations of BPR. Seokwang and 23 others showed high populations and serious damages. Yield increasea(%) with insecticides were low on Gaya(12%), Samgang(29%) and Hangangchal(35%), but very high on Bongkwang(260%), Palgueum(223%), Songjeon(200%), and Guanauk(200%).

• Journal of Life Science
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• v.29 no.2
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• pp.202-208
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• 2019

Brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae), is one of the most important migratory pests damaging rice in Korea. It invades annually from tropical and subtropical areas via continental air streams. It is necessary to determine the resistance levels of rice varieties in order to control efficiency. The honeydew excretion, development, and reproduction of the migratory BPH were studied by region in a laboratory at $25{\pm}2^{\circ}C$ and $65{\pm}5%\;RH$ and a 16L: 8D photoperiodism conducted on three BPH resistant genes: Bph1, Bph2, and Bph18. The information obtained was reported using the jackknife method, and we created life table statistics accordingly. The feeding amount of Bph1 resistant gene was lower than that of resistant genes. The developmental periods of immature stages ranged from $13.7{\pm}0.10d$ on Bph2 (Namhae, 2015) to $18.5{\pm}1.06d$ on Bph2 (Sacheon, 2016). Reproductive period and female longevity were longest on the non-resistant genes, Bph2 and Bph18 (except 1980s), and the highest fecundity of N. lugens was observed on the two BPH resistant genes. Highest net reproductive rates ($R_0$) were calculated on Bph2 by region. Intrinsic rates of population increase ($r_m$) showed a difference in resistant genes by region. These population parameters showed that migratory regions and biological characteristics of N. lugens vary annually.

• Korean journal of applied entomology
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• v.20 no.4 s.49
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• pp.207-211
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• 1981

It has been documented that the resistance to planthoppers is attributed to the feeding preference of the insects. This might be related to difference in the amount of feeding plant sap between resistant and susceptible hosts. In this aspect, this study was conducted to verify it and to develop an effective screening method for resistance to planthoppers by tracer technique. An effective P-32 labelling of rice seedlings at $2\~3$ leaf stage was dipping the roots in concentration of $0.1{\mu}Ci/ml$ solution for 48 hours. Radioactivity was significantly higher in planthopers fed on susceptible variety for 48 hours as compared to those fed on resistant variety. Radioactivity of adults was higher than that of nymphs and also higher in female than male. The results were highly correlated to that indicated by the feeding preference of the insects and therefore, considered to be valid for a screening technique.

• Korean journal of applied entomology
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• v.23 no.3 s.60
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• pp.153-157
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• 1984

The present work was designed to study the yield loss on rice at different appearance days of hopperburn caused by the brown planthopper(BPH), Nilaparvata lugens Stal, when rice plants were infested with BPH on booting and heading stages. Dead plants were colleted from 23 days after heading stage with intervals of 5 days. Yield losses by the initation of BPH infestation was greater at tooting than at heading stage. Compared to the uninfested plot, there was a reduction in 1,000 grain weight and filled grain percentage at both stages. Positive relationship was observed between rice yield(Y) and the number of days from heading to the appearance of the hopper-burn. Regression equations calculated were; for BPH feeding from booting $\hat{Y}(g)=10.145X-16.374(r=0.9726^{**})$, and for BPH feeding from heading $\hat{Y}(g)=9.792X+26.936(r=0.8850^{**})$.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.236-242
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• 2008

Laboratory and greenhouse experiments were conducted to evaluate the effect of root zone application of some systemic insecticides for control of the brown planthopper (BPH), Nilaparvata lugens, as one of the management option to minimize the adverse effects and maximize the efficacy of insecticide application. Five systemic insecticides, namely, carbofuran, carbosulfan, diazinon, ethoprophos and imidacloprid, as granular formulation were placed in the root zone and measured the mortality, fecundity, and nymphal survivorship of the planthopper. Diazinon and ethoprophos did not show the significant mortality of the BPH. When the BPH were inoculated at the day of carbofuran treatment, adult mortality was shown almost 100% at seven days after treatment and BPH nymphs were remained very few on rice at 25 days after treatment. When carbofuran were placed 10 days before the BPH inoculation, it showed almost 100% adult mortality after one day, and no nymphs were found until 25 day after inoculation. Efficacy of carbofuran on BPH when applied in 10 day-old rice was higher than in 30 day-old rice. These results indicated that the root zone application of carbofuran can control N. lugens effectively with less adverse effect to the natural enemies inhabited on rice plants.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.361-372
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• 2018

Migratory insect pest populations migrate from the southern China to Korea through jet streams. In Korea, 5 major migratory insect species are important, i.e. Nilaparvata lugens, Sogatella furcifera, Laodelphax striatellus, Cnaphalocrocis medinalis and Mythimma separate, which are damages to the major crops, rice. This study was conducted from late July 2016 to early September 2016 and from July 2017 to August 2017 in rice paddy of Jeolla-province. C. medinalis and M. separata collected using pheromone traps, while N. lugens, S. furcifera and L. striatellus collected using 3 methods (visual surveys, sweeping surveys, sticky traps). SADIE (Spatial Analysis by Distance IndicEs) among geostatistics was used to analyze migratory insect pests. SADIE was used to analyze spatial distribution and index of aggregation $I_a$, index of clustering $V_i$, $V_j$ were used to investigate the spatial distribution. Also, the clustering indices were mapped as red-blue plot. C. medinalis and M. separata showed different distribution based on SADIE spatial aggregation analysis and red-blue plot analysis. Initial spatial distributions of L. striatellus and other planthoppers were differed for sampling location and time.