• Animal cells and systems
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• v.12 no.1
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• pp.47-52
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• 2008

Effects of wood vinegar on the activity of various insecticides were determined by measuring the mortality of two species of rice planthoppers, Nilaparvata lugens and Laodelphax striatellus. Wood vinegar itself did not show insecticidal activity on planthoppers. When the planthoppers were treated with wood vinegar mixed with one of insecticides such as BPMC, dinotefuran, imidacloprid, carbosulfan or insect growth regulators, the planthopper mortality induced by carbosulfan was greatly increased by the wood vinegar in comparison with a single carbosulfan treatment. Wood vinegar showed no effect on other insecticides. In addition, the wood vinegar-carbosulfan mixture significantly reduced AChE activity of planthoppers, which is a target molecule of carbosulfan. This result suggests that wood vinegar has a synergistic effect on the insecticidal activity of carbosulfan. Our study provides information on a potential role of wood vinegar in facilitation of activity of specific insecticides.

• Research in Plant Disease
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• v.24 no.3
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• pp.202-212
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• 2018

Major viruses infecting rice are transmitted by planthoppers such as small brown planthopper (SBPH), brown planthopper (BPH) and white-backed planthopper (WBPH). In this study, we investigated planthoppers captured during 2015 to 2017 by a smart sky net trap (SSNT) system installed in 40 areas in Korea, which is an automatic, rapid and real-time insect surveillance system. The average rates of captured migration plnathoppers was 27.5%, 17.2%, 15.3% and 10.9% in Chungcheongnamdo, Jeollanamdo, Jeollabukdo and Gyeonggido, orderly. The highly migrated month was July for SBPH, July to August for WBPH and August for BPH. To investigate the viruliferous rates of planthoppers of rice during 2015 to 2017, we performed RT-PCR using specific primers for each rice virus. RBSDV was detected from 0.4% in SBPH, while no viruses were detected in BPH and SBPH. Rice planthoppers exist all around in Asia. They can move long distance by wind from southern countries to Korea. Monitoring the migration of rice planthoppers and their viruliferous rates is important to prevent the outbreaks of rice virus diseases.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.57-63
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• 2003

Accurate forecasting of occurrence time and abundance of insect pests is essential for developing technology of integrated pest management system. Digital image processing algorithms were utilized to automatically recognize rice planthoppers which are major insect pests in the rice cultivation field and were subsequently used to estimate densities in the field for efficient forecasting of insect pests. To the images taken in the rice field, image decomposition, top-hat transformation, threshold, and minimum and maximum filter were implemented for patterning individually the brown planthopper specimens attached at the bottom area of rice stems. In average 95.8cio of images were correctly recognized for estimating densities by the developed system, and the recognition rate was higher than that obtained from direct observations by experienced observers. Furthermore, the size of the recognized specimens was measured and was used for estimating the age structure in the observed brown planthopper populations.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.04a
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• pp.128-128
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• 2022

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.11a
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• pp.41-41
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• 2002

• Korean journal of applied entomology
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• v.41 no.2
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• pp.75-83
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• 2002

The hypertext-based polychotomous key in m (World Wide Web) was developed to improve the identification accuracy of planthoppers caught by the light trap in Korean paddy fields. The effects of it were tested by 12 students who are not familiar at the identification of insects. When they used the hypertext, it was improved that the ability of them to recognize Sogatella furcifera (Horvath) and Laodelphax striatellus (Fallen). Identification accuracy of the former was increased significantly from 56% to 83% and that of the latter was also increased significantly from 47% to 80%. However, many students still have difficulty in the recognition of Nilaparvata lugens (Stal).

• 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 Organic Agriculture
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• v.26 no.3
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• pp.489-500
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• 2018

Rural Development Administration (RDA) is promoting the AFACI IPM (Asian Food & Agricultural Cooperation Initiative program). AFACI consist of 12 countries including Bangladesh, Cambodia, Thailand, Vietnam and so on. The main goal of the AFACI IPM project is 'Establishment of an international cooperative network for the best management of migratory rice planthoppers and setting data-base of pests occurrence information. As a result of the suvey, Planthoppers were increasing all the way from tillering stage to ripe stage and do not appear to be peak of one or two like korea case. In detail, 1,673 of BPH (Nilaparvata lugens) occurred in survey site of Svay Reang, Cambodia, followed by 1.237 at Dobila, Bangladesh. In the case of White backed planthopper (Sogatella furcifera), 1,163 of WBPH occurred in survey site of Dobila, Bangladesh and 849 WBPH were collected at Hamkuria, Bangladesh. It is expected to verify the occurrence and movement patterns of hoppers among member countries in the future.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.403-413
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• 2008

This study was conducted to select excellent tank mix combinations of pesticides for aerial application by manned helicopter. Among 209 pesticide combinations of 3-way tank-mixing for aerial application, a total of 93 recommendable combinations including tricyclazole SC+validamycin-A SL+imidacloprid SL were finally selected for the simultaneous control of key pests on paddy rice such as blast, sheath blight, brown planthopper and moth. The selected combinations were not phytotoxic to rice plants and nearby non-target crops, and excellent in physicochemical properties of ultra low volume (ULV) spray solutions. The efficacies on sheath blight, brown planthoppers and white-backed planthoppers of pesticides sprayed by aerial application were similar to those of pesticides by conventional spraying. Total cost of aerial application in paddy rice was very economical as one fourth level of that of conventional spraying.

• Korean journal of applied entomology
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• v.33 no.4
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• pp.270-280
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• 1994

This study was conducted to establish a nce insect pest control system, ~ es.ys tematic application of insecticides using carbohran and buproiezin, in Korea. The effects oi various dates of application and rates of buprofezin (25% WP) after carbofuran (3G) soil incorpombon in late May on the pop~~lation densities of the brown planthoppa (BPH) immigrating in July were investigated Appropriate application tune of buprofezin for the BPH that had evaded insecticidal effect of 5011 incorporated carbofuran was late July-early August. Application rate of buprofezln at 7.0g a.i/lOa was enough to suppress the BPH density. Buprofezin treatment after carbofumn soil incorporation could also suppress the whlte backed planthopper population but did not affect the densities oi the paddy rice spiders. Considering the charactenstics of occurring patterns of the nce insect pests in Korea. buprofezin treatment m late July or early August after carbofuran soil incorporation in late May can be a useful application system of ir~sectic~deins controlling early season Insect pests and migmtoly planthoppers on rice.