• Korean journal of applied entomology
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• v.52 no.4
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• pp.437-448
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• 2013

Hemipteran bugs, which were previously considered as secondary pests, have currently become important pests of numerous crops. Among them, Riptortus pedestris (Fabricius) is a major species that occurs in Korea, Japan, China, and South Asian countries. Riptortus pedestris infests leguminous crops like soybean, vetches, and red clover; fruit trees like persimmon and yuju; and grains like barley, foxtail millet, broomcorn, and sorghum. Riptortus pedestris causes the greatest damage to soybean, as it is the most suitable host for the bug. Feeding damage during pod formation significantly reduces the yield of soybean. Currently, 17 insecticides, including diazinon and etofenprox, are registered for the control of hemipteran bugs in Korea, and growers apply insecticides two to three times on a regular basis. Aggregation pheromone traps are widely used as a monitoring tool and partial control measure. The aggregation pheromone of R. pedestris attracts conspecific adults and nymphs and is used for food exploitation rather than sexual attraction. In addition, the pheromone serves as a kairomone for egg parasitoids such as Gryon japonicum (Ashmead) and Ooencyrtus nezarae Ishii. As a new method of pest management, nonviable host eggs were included in the pheromone trap to catch R. pedestris and propagate parasitoids. As a part of cultural practices, resistant soybean varieties with specific color and size of pod and control of flowering time through the alteration of planting date can be used. For the effective management of R. pedestris in the near future, development of cultural practices that can support natural control factors and the use of multiple control tactics are needed.

• Research in Plant Disease
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• v.18 no.3
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• pp.245-249
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• 2012

The small brown planthopper (Laodelphax striatellus) is one of the most important rice pests in Republic of Korea because it damages rice plants not only by sap-sucking but also by transmitting Rice stripe virus (RSV). Outbreaks of RSV are closely related to outbreaks of the small brown planthopper (SBPH). Therefore, it is very important to control SBPH for the management of RSV. Mass-migrating SBPH collected by aerial net traps in June 2011 at Taeanup, Geunheungmyon and Gonammyon in Taeangun were examined for virus carrier status and effects of the pesticide, 'Myungtaja', on the control of RSV. Among 1,217 SBPH trapped, about 7.7% were detected as RSV positive and 4.4% were positive for Rice black streak dwarf virus (RBSDV) by RT-PCR. After the mass migration, pesticide 'Myungtaja' was sprayed once or twice on rice fields and compared to untreated fields. The incidence of RSV was not affected by the frequency of spraying 'Myungtaja' but was influenced by the time of pesticide treatment. Myungtaja' treatment within 5-7 days after mass migration resulted in the most efficient RSV control, resulting in RSV incidence decreased by 87.6% compared to the control. Therefore, we conclude that pesticide spraying for RSV control was most effective when it was done within 5-7 days after mass migration.

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.284-288
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• 2010

A series of experiments was carried out for selecting insecticides and determining proper spraying time to control pea weevil (Bruchus pisorum Linnaeus) in Jeonnam area. In the field trial two times spray with diazinon, carbaryl, imidacloprid, spinosad, etofenprox, clorpyrifos-methyl showed good control effect and threetimes spray showed the better control effect. The second spray (spraying on 10th of May) took the major role of insecticide effectiveness expression for controlling pea weevil. Further trial for selecting insecticides among organophosphates to control pea weevil in lab was conducted and every organophosphate insecticide tested was very effective to pea weevil even at the concentration of one forth of its recommending concentration.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.335-339
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• 2019

The white peach scale (Pseudaulacaspis pentagona) is a significant pest of trees belonging to the Rosaceae family. We investigated the effect of ten insecticides on hatching rate of first instar white peach scale larvae (crawlers). The insecticides are Dinotefuran WG, Benfuracarb WG, Pyrifluquinazon WG, Clothianidin SG, Buprofezin WP, Buprofezin+Imidacloprid SC, Buprofezin+Etofenprox WG, Buprofezin+Thiacloprid SC, Benfuracarb+Buprofezin WG, Acetamiprid+Buprofezin EC. We observed that several crawlers emerged in early May, with the average number being 45.7. Hatching period was approximately 14 days, and the hatching success rate was approximately 77.7%. Overwintering females produced an average of 58.7 eggs. All insecticides achieved 100% mortality in crawlers. Our results suggest that these insecticides can effectively control white peach scale when used at the crawler stage.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.685-690
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• 2000

Caliroa carinata (Zombori) has heavily damaged the forests of Quercus mongolica in Sangju, Kyongbuk, Korea since 1996. However, information on the ecology and control of this pest was badly scarce. Thus we tried to study the ecology and chemical control of the sawfly through this study. Caliroa carinata is one generation per year. The adult sawflies emerged from June 8 to July 5 with peak at June 18. A female adult laid 11 eggs in rows on the backside of a leaf along the midribs and larger veins. Larvae have six instars, and the developmental period required to complete the larval stage was 19 days and 17 days at temperatures of $20^{\circ}C$ and $25^{\circ}C$, respectively. Each larval stage required 2-4 days to complete the development. The sawfly mostly preferred Quercus mongolica and Q. dentata, while avoiding Q. variabilis. Such insecticides as Tebufenozide, Flufenoxuron, Etofenprox, and Fenitrothion were sprayed on host plant leaves infected with test larvae in order to study the mortality. After 3 days of insecticide treatments, the mortalities were thoroughly examined. All insecticides showed higher than 95% of mortalities. Control values were also higher than 93%. The optimal season of insecticide application for pest control was estimated from late June to early July.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.306-320
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• 2015

This survey was carried out in 2014 to estimate the pesticide residue levels in commercial environment-friendly agricultural products in Seoul metropolitan area. Pesticide residues in 27 commodities were examined and analyzed using LC-MS/MS, which can simultaneously detect up to 85 pesticides. A total of 441 samples were collected and analyzed. Among the detected samples, the residue levels in 1.2% of organic agricultural products and 2.2% of pesticide-free agricultural products exceeded the maximum residue limits (MRLs); hence, 1.8% of the total samples exceeded the MRLs. The safety of the detected pesticides was assessed by monitoring the acceptable daily intake level (ADI) and acceptable dietary exposure (ADE) to the pesticides via consumption of the commodities. ADI and ADE are found to be 0.07728-9.46530% and 0.00141-0.17210%, respectively, which means that the residual pesticides in the environmental-friendly agricultural products in Korea are below the safe limit and therefore, pose no potential public health risks.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.431-448
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• 2021

We decided the efficient application timings of organo-synthetic insecticides for controlling the first generation larvae of O. furnacalis through investigations of insect stage-specific densities, damage aspects in maize, and effects of insecticides. A waxy maize cultivar, Ilmichal, was cultivated from April 20 (sowing) to July 26 (harvest, dough stage of maize) in Suwon, 2016. The maximum and 50% cumulative catch dates of the overwintering generation adults in the sex pheromone trapping were May 29 and May 31, respectively. Most of the first generation larvae finished their occurrence till the early reproductive stage of maize. The first generation larvae fed on leaves inside the whorl leaves before tassel and stem development of maize, sequentially moved to tassel and stem, and then moved finally to stem and ear parts. In the results of insecticide applications at different dates, the 9-11 leaf stage (June 10~17) and the 6-7 leaf stage (June 3) of maize were the most efficient application timings for direct spray of Etofenprox EC to maize, and for application of Carbofuran granules onto soil surface, respectively, which resulted in suppression of tunnelling damages. The timings for the two insecticides were 12-19 days and 5 days after the adult maximum catch date, respectively. Those timings after the 50% cumulative adult catch date were advanced 2 days.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.231-236
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• 2021

The Aphid, Myzus persicae, and the bean bug, Riptortus clavatus, are major insects in crops. This study examined the insecticide susceptibility and phytotoxicity of insecticides dispersed using an Unmanned Aerial Vehicle (UAV, multi-copter) against the insects. Sulfoxaflor suspension concentrate (SC, 16X) on potato fields and etofenprox, methoxyfenzide suspo-emulsion(SE, 8X) on soybean fields were dispersed after deploying water-sensitive paper within the field to measure the distribution pattern and coverage index of the falling insecticide. Both insecticides showed a controlled mortality of 76.4% against aphids and 97.5% and 94.4% against the 2nd nymphal, and 5th nymphal stage of the bugs, respectively. The droplet distribution was less than 0.5mm, and coverage analysis revealed an inside and outside coverage of 3.1 and 1.6, respectively. The surrounding area was affected by insecticide spraying using a multi-copter. This study is expected to help expand UAV control and use it safely in the future.

• The Korean Journal of Pesticide Science
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• v.18 no.1
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• pp.26-32
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• 2014

This study was conducted to evaluate pest control efficacy of environment-friendly agricultural materials (EFAMs) according to their spray time and frequency against alfalfa weevil, Hypera postica Gyllenhal, at Chinese milk vetch field in Miryang, Korea. Larva, pupa and adult of H. postica occurred more in year 2010 than those in 2011, and the larval population peaked 5 days faster in year 2010 than on $10^{th}$ May in 2011. Control efficacies of EFAMS sprayed on various time and in several frequencies to H. postica during April in 2010 were 73.6%, 71.9% and 66.2% at single spray in early, middle and late April, respectively and ranged from 77.1% to 78.9% when sprayed twice. With three times spray the control efficacy averaged 87.2%. Control efficacies of EFAMs with a single application in early, middle and late April in 2011 were 57.9%, 66.8% and 65.2%, respectively and ranged from 73.7% to 76.8% when sprayed twice. Control efficacy averaged with 82.7% when EFAMs were sprayed for three times. Accordingly, control efficacy of EFAMs against was increased with increasing spray frequency. Among the tested, Ungsamee(R), Wangjoongwangeco(R) and Muchungjidae(R) with a single application showed relatively higher control efficacy with a 4 to 16% lower control rate than a chemical insecticide, etofenprox 20EC. Therefore, Ungsamee(R), Wangjoongwangeco(R) and Muchungjidae(R) can be effectively used for management of H. postica when sprayed at early April for high occurring population and middle April for low occurring population with a single spray.