• 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 applied entomology
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• v.53 no.4
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• pp.497-501
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• 2014

The small brown planthopper, Laodelphax striatellus (Fall$\acute{e}$n) (SBPH) is one of the important rice pests in Korea, which transmits rice stripe virus (RSV) to rice. This pest is an indigenous species in Korea and has also known to migrate from China to the western coastal areas of Korea. This study was conducted to investigate the wing morphs of SBPH and its parasitism rate of Haplogonatopus atratus Esaki et Hashimoto in Korea. In 2014, SBPH were collected in April and July from 16 sites throughout South Korea and their wing morphs and parasitism rates were measured under the microscope. Percentage of brachypterous male in July was significantly declined compared to that in April, while that of brachypterous female did not change. A positive relationship was found between latitude and percentage of brachypterous adults in April. Parasitism rate of both nymphs and adults were higher in April than July. In addition, nymphal parasitism rate was generally higher in western coastal areas.

• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.49-55
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• 1984

This study was carried out to investigate the biological performance of the brownplanthopper, Nilaparvata lugens Stal, reared on rice plants at different growth stages; maximum tillering, booting, heading with and without panicles, and milking. The results obtained are as follows: The rice plants at the maximum tillering stage gave the best in the longevity, oviposition period, and the total number of oviposited eggs for the macropterous females, and the worst with the booting stage. For the brachypterous females, however, the best results were obtained from the rice of which their panicles had removed after heading. There was no significant difference in the hachability of eggs and the developmental period of the nymphs in the next generation, but the nymphal mortality was the highest with the milking stage and the lowest with the maximum tillering and heading stage without panicles. The longest life span was shown in males derived on the maximum tillering stage, and the shortest for milking(macropterous type) or booting (brachypterous type) stages. Coefficientes of variances in longevity and number of eggs for the adults emerged from heading stage without panicles were lower than those with panicles intact, and such trend was more obvious in brachypterous adults, especially for the females. The biological performances of the BPH have close relationship with the translocated organic material at the feeding site which showed considerable difference with the growth stages of the rice.

• 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.54 no.4
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• pp.419-423
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• 2015

Small brown planthopper (SBPH), Laodelphax striatellus, gives a lot of damage to the rice by insect vector of rice stripe virus (RSV). This study compared the RSV acquisition and infection rates according to wing form, sex, and life stage of SBPH. The RSV acquisition rate in macropterous and brachypterous was 60.7% and 63.1%, respectively. The RSV acquisition rate by sex was 61.9% in female and 52.2% in male. However, there was no difference in significance. The RSV acquisition rate of nymphs and adults was 51.2% and 58.7%, respectively. The RSV infection rate by wing form was 53.3.% in macropterous and 48.2% in brachypterous. According to life stage, nymphs was 38.2% and adults was 42.6%. There was no difference in significance. On the other hand, female and male of RSV infection rate was 50.5% and 22.3%, respectively. There was a significant difference. Additionally, developmental periods of SBPH by RSV infection, the longest when inoculated with RSV-infected SBPH in healthy rice, while the shortest when inoculated healthy SBPH in healthy rice.

• Korean journal of applied entomology
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• v.32 no.1
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• pp.68-75
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• 1993

Morphometric investigations of the leg characters of both sexes of brachypterous Korean N. lugens biotypes were made. Simple and multivariate statistical analyses revealed that the three N. lugens biotypes differed from one another. The amount of variation and segregation between and among the three biotype populations were approximated by the scatter plot diagrams based on the computed discriminant scores. The variables of leg characters provided the most significant segregations of three biotype populations, thus, categorizing the three biotypes as distinct intraspecific populations of N. lugens.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.137-141
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• 2005

Though many insecticides are commercially available, development of resistance, pest resurgence and effects on non-target organisms led to the search for alternate insect pest management (IPM) strategy based on larval growth and reproductive fitness. Reproductive potential of insects depends on its acquiring of vitellogenic competence which is under hormonal control. Exogenous application of analogues of JR (JHAs) and ecdysterone could derail normal development and reproduction in insects by manipulating an array of physiological processes. In the rice pest, brown planthopper, Nilaparvata lugens, JHA, hydroprene induced metathetely from the fifth (final) instar nymphs in an age-dependent manner. Day 0 of the final instar showed highest sensitivity to induce this abnormal development. Adults emerged from treated day 3 nymphs looked normal. Both the morphotypes were reproductively incompetent and showed partial to complete sterility. Pre-adult exposure of the ovarian tissue to hydroprene suppressed mitotic division of germinal cells and induced abnormalities in the later s1ages of growth and differentiation of ovary in N. lugens. More over the nymphal exposure to hydroprene inhibited patency changes of follicular epithelium and affected competence of the follicles for yolk sequestration. In the absence of ovarian growth and oocyte differentiation, germarium found disintegrated, trophic core regressed and terminal oocytes resorbed. Hydroprene exposure to newly ecdysed brachypterous females did not affect ovarian development and egg production. Proper larval-adult transition appeared as a. prerequisite for vitellogenic competence in N. lugens for which the ovarian tissues must be exposed to ecdysterone in the internal milieu devoid of JH.

• 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.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.317-322
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• 2018

In Vollenhovia emeryi (Hymenoptera: Myrmicinae), the queen and the male are known to be clonally reproduced. Its colonies can be classified into the two morphs with the wing length of the queen caste. The morph with normal wings is called the long-winged and the other the short-winged that is brachypterous. Even though the two morphs are considered a species, investigation on the species status of the two morphs was suggested with natural separation in nature and the distinctive wing morphology. It has yet to be determined whether the clonally reproduced queen caste is haploid or diploid. Our data clearly show that the two morphs are the same species and the queen caste is diploid on the basis of the genome size data comparison.

• 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.