• Journal of Life Science
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• v.9 no.2
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• pp.121-126
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• 1999

Some attempts were made to investigate the honeydew excretion of the brown planthopper(BPH), Nilaparvata lugens Stal, biotypes in terms of instal nymph, days after emergence, macropterous and brachypterous mated and unmated female, and macropterous female with different sources fed on 60-day-old rice cultivars with different resistance genes. The feeding amount of the BPH biotypes was measured by using the honeydew excretion test. The feeding amount of fifth instar on Miryang 23 with no resistance gene was higher than that of Cheon-gcheongbyeo with Bph-1 gene by two times. Macropterous and brachypterous females showed low feeding amount at first day after emergence, but they showed high feeding amount from second days after emergence. Also the feeding amount of brachypterous female was higher than that of macropterous female. In addition, the feeding amount of BPH was in the order of nymph

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.526-532
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• 2017

Development, survival, and reproduction of brown planthopper (BPH) Nilaparvata lugens $St{\aa}l$ (Hemiptera: Delphacidae), were studied in laboratory at $25{\pm}2^{\circ}C$, $65{\pm}5%$ RH and a 16L : 8D hours photoperiodism on five rice cultivars of: Dongjin 1ho, Chungchungbyeo, Jangseongbyeo, Chinnongbyeo and Jungmo 1045. BPH nymphs successfully survived on all rice cultivars, although survival rate was lowest on Jangseongbyeo (36.0%). Developmental time of immature stages ranged from $11.7{\pm}0.59d$ on Jungmo 1045 to $12.8{\pm}0.59d$ on Chinnongbyeo. Reproductive period and female longevity were longest on Dongjin 1ho, Chinnongbyeo and Jungmo 1045 while highest fecundity of N. lugens being observed on these three rice cultivars. Highest and lowest net reproductive rates were calculated on rice cultivars, Jungmo 1045 and Jangseongbyeo, respectively. Mean generation time was the longest on rice cultivar Dongjin 1ho. Respective descending order of intrinsic rates of population increase were on Jungmo 1045, Chinnongbyeo, Dongjin 1ho, Chungchungbyeo and Jangseongbyeo. These population parameters showed that N. lugens can successfully survive and reproduce on Chinnongbyeo and Jungmo 1045.

• Korean Journal of Plant Resources
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• v.2 no.2
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• pp.298-305
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• 1989

This study was carried out to understand the immigration period, climatic conditions for mass immigration and bionomical characters ofthe brown pLanthopper(BPH) in Hae NamThe results are as follows ; (1) The Periods of first immigraion and mass immigration of BPH , were from the late June to early JuLy and from earlyto mid JuLy in HaeNam, that were faster about 15-30days than in inland of ChonnanThe climatic factors that related closely to mass immigration wereas follows ; temp.: $20{\;}~{\;}25^{\circ}C$, humidity : 86 ~ 95 % , wind direcion : SW, wind velocity: 1.0 ~ 2.9gm/sec. (2)The population of immigranted BPH was in the field much more overthe mountain near coast than other places . Biotype composition showed that biotype I was on the decrease and biotype II, III were on the increase (3)The bionomical characters were variable, for climatic conditions,that egg stage, nymphal stage and adult stafe of immigranted BPHwere 9-12days, 13-16days and 12-36days respectively, that hatchability(%) and emergence rate ( % ) were higher than 80%. The adult Longevity in female and macropterous BPH showed Longerthan that of male and brachypterous respectively. (4) The distance of nymphs and brachypterous adults move by walking was within 16cm over the water surface, by hopping was within 20cm horizontally.

• Korean journal of applied entomology
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• v.40 no.1
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• pp.83-88
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• 2001

Residual effect of imidacloprid on brown planthopper (BPH) and residues on rice plant were investigated in pot and field tests. Residual effect (showing 100% mortality) of imidacloprid of granule formulation on the BPH lasted for 40 days at a recommended dose (0.3 kg a.i./ha) and for 30 and 20 days at a half and a quarter of the recommended dose, respectively. In case of liquid formulation of imidacloprid, the residual effect lasted for 40 days at both recommended dose (0.032 kg a.i.1ha) and a half of it, and lasted for 30 days at a quarter of it. The next generation formation of BPH was throughly depressed by the imidacloprid application at the former generation. This result supports the residual effect of imidacloprid on BPH. Seed dressing (3 ghg) showed insecticidal activity (96.7% mortality) for 55 days after treatment. When granule formulation of imidacloprid was applied to soil at a recommended dose , imidacloprid residue in leaves of rice plant increased up to 0.46 ppd for 6 days and then decreased to 0.09 ppm on 40 days after application. Residue of imidacloprid in leaves of rice plant increased up to about 0.23 ppm and about 0.2 ppm for 6 days when applied at a half and a quarter of the recommended dose, respectively and after that they decreased.

• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.244-250
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• 1983

This study was carried out to analyst the damage due to the brown planthopper, Nilapalvata lugens Stal, at different stages(maximum tillering, booting, heading, and milking) of rice. The results are as follows: The population density of the migrating and the first generations of the brown planthoppers seemed not to be large enough to cause significant effects on the plant height and the number of tillers, while the second and the third generations caused significant reduction in 1000 grain weight(Yl) and the filled grain percentage$(Y_2)$. They were very closely related to the population density(X) of tile second generation of the BPH; $$Y1(g)=25.602-0.0213X(r=-0.5205^{**})$$ $$Y2(\%)=76.97-0.1370X(r=-0.4820^{**})$$ The relationship between rice yield (Yg) and the accumulated total density (X) of BPH per hill by the time of harvest; $$Y(g)=24.694-0.0576X(r=-0.6959^{**})$$ Since the source of the outbreak BPH is the first generation, it nay conclude that the detailed information on the population status of the first generation; density, age components, ratio of the brachypterous form, are very important in relation to management of the pest.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.61-65
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• 2005

Using two japonica rice cultivars (Ilpumbyeo and Sanghaehyanghyella), which are distinguishable by the brown planthopper (BHP) resistance maker (R208), a relationship between the BPH resistance gene (Os-Bil) and salt-tolerance was investigated. To do this, changes in the expression level of Os-Bil by the salt stress were quantified by the real-time PCR in the two cultivars, and compared with those in other two indica rice cultivars (Pokkali and IR29). In Ilpumbyeo, the expression level of Os-Bil decreased by the treatments of 50 and 200 mM NaCl in a concentration-dependent manner, and in Sanghaehyanghyella it rather increased slightly at 50 mM but decreased drastically at 200 mM. Comparably, IR29, a salt-sensitive cultivar, showed a reduction of the Os-Bil gene expression after the treatment of 100 mM NaCl, but Pokkali, a salt-tolerance cultivar, rather increased about two times in the level of Os-Bil transcripts. These results suggest that the BPH resistance gene may involve in the difference in the salt-tolerance at least between the two indica rice cultivars.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.351-358
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• 2016

Consistent with a previous study on the brown planthopper Nilaparvata lugens (BPH) (Seo et al., 2009), we identified seven distinct EPG waveforms (np, L1, L2, L3, L4-a, L4-b, and L5) in adult female Laodelphax striatellus (SBPH) that fed on rice plants, by using the direct current electrical penetration graph (DC-EPG) system. The shape of waveforms and the pattern of occurrence of each waveform of SBPH were very similar to those of BPH. L3 and L4-a always occurred prior to L4-b. Periodical honeydew excretion was observed in L4-b only. Microsection observation following laser stylectomy revealed that the tips of SBPH stylets severed in L3, L4-a, and L4-b were commonly located in or near the phloem region of rice plants, but were located in the xylem in L5. Plant sap flowed from the stylets severed in L4-b only, and its main carbohydrate component was detected as sucrose by HPLC analysis. These results and the patterns of EPG waveform progress in SBPH suggested that feeding activities on rice plant tissue were relevant to each EPG waveform. L1 and L2 corresponded to the initiation of stylet penetration and stylet movement with salivation on the outside of the vascular bundle. L3 and L4-a were related to feeding activities within the phloem region in preparation for phloem sap ingestion. L4-b was closely associated with phloem sap ingestion, and L5 corresponded to xylem feeding behavior.

• Journal of Life Science
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• v.30 no.9
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• pp.798-803
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• 2020

Late in the 1960s, South Korea established cultivation technology and began breeding new "Tongil" type rice cultivars by crossing indica and japonica. To date, this cultivation technique has been used to produce a wide variety of cultivars to meet consumer preferences and adapt to extreme weather conditions. Once major genetic traits are no longer segregated through advanced generations, varieties obtained from a cross between different crops may become a new variety. In this study, we confirmed the agronomic traits of F₄, F₅, and F₆ by advanced generation a population in which drought tolerance and brown planthopper (BPH) resistance were crossed. HV23, Ilmi/HV23, and Drimi2ho/HV23 were used. HV23 was drought-tolerant, and Drimi2ho was resistant to BPH. As a result, it was possible to consider that the agronomic traits were fixed because none of them showed a significant difference from the others. While it takes more than 10 years for the pedigree method of breeding, this study confirmed that the agronomic traits were fixed in 4-6 years. In the future, we will investigate the homology of the CaMsrB2 gene and the Bph1 gene, to confirm that both genes are closely related to each other, and analyze the stable inheritance of the introduced gene for multiple successive generations.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.51-60
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• 1985

This paper was performed to study the nature of varietal resistance of some Korean-new rice cultivars to the brown planthopper (BPH), Nilaparvata lugens ($ST{\AA}L$). The rice cultivars tested were Cheongcheong, Gaya, Hangangchal, Samgang, Nampoong and Yeongpoong which have been reported as having resistant genes for the BPH. The check varieties were Jinheung, Sangpoong and Chucheong for susceptible and IR-36 for resistant. The factors studied were referred to the seedling responses, preference in feeding and oviposition of BPH, antibiosis (nymphal development, adult emergence and sex ratio, adult body weight, population build-up, feeding amount and amylase activity), and chemical composition (inorganic components, chlorophyll contents, cell wall components, amino acids and esterase isozymes) of leaf- sheath and/or roots of rice plants. In conclusion, the natures of varietal resistance of rice cultivars to the BPH were not only correlated with the resistant reaction of rice plant, but also they were related with the non preference in feeding and oviposition and those resistant cultivars had the antibiotic effects to the insects. Their antibiotic effects of rice cultivars to the BPH would be related with some of the chemical components of rice plants, such as the contents of magnesium oxide (MgO), and chlorophyll and the different esterase isozymes.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.258-264
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• 2004

The pyrazole family was discovered as effective insecticides/acaricides, and fenpyroximate and tebufenpyrad were introduced in the market. In this study, new series of pyrazole oxime ethers were designed and synthesized. The pyrazolone 1 was prepared by the condensation of ethyl acetoacetate with methylhydrazine, and then subsequently subjected to the Vilsmeier-Haack chloroformylation yielding 4-formyl-5-chloro-pyrazole 2. The nucleophilic aromatic substitution of 2 generally allowed the introduction of a wide range of heterocycles into the pyrazole ring. The resulting pyrazole aldehydes 3a-i were readily converted to the corresponding pyrazole oxime derivatives 4a-i, and subsequently to 5-substituted pyrazole oxime ether derivatives 6a-i. The screening assay results clearly show that the activities of 6d were comparable to those of fenpyroximate (6a) against BPH, DBM, and TSSM. It indicates that 6d has a potential to be developed as an insecticidal agent.