• Korean journal of applied entomology
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• v.60 no.3
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• pp.305-312
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• 2021

This study was carried out to investigate insect pests and their damage caused to commercial amaranth in Gangneung, Gangwon-do, Korea, during 2019-2020. A total of seven families and 18 species were identified including three species of aphids, twelve species of stink bugs, and four species of moths. Among them, five species caused significant economic damage due to a large number of occurrences; Aphis fabae, Nysius plebejus, Polymerus cognatus, Spoladea recurvalis and Spodoptera exigua. Aphids started to occur from the end of April, and showed the greatest incidence in early June. Three Nysius species occurred from mid-May and showed the maximum density in late August, and then its population decreased from the beginning of September. Two species of moth caterpillars began to occur from mid-August and damaged amaranth until mid-October. Comparing the yields between amaranth plants with and without a spray of pesticides for each pest, the yield loss of seed by aphids and stink bugs were 51.9% and 69.8%, respectively. Also, the reduction rates of leaf biomass by S. recurvalis and S. exigua were 72.5% and 36.5%, respectively.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.519-528
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• 2022

The western flower thrips, Frankliniella occidentalis, infests the hot pepper cultivated in greenhouses and has been considered to be controlled by a natural enemy, Orius laevigatus. However, sporadic outbreaks of the thrips due to fast population growth occasionally need chemical insecticide treatments. This study was designed to develop an optimal integrated pest management (IPM) by using selective insecticides along with a safe re-introduction technique of the natural enemy after the chemical insecticide treatment. First, chemical insecticides were screened to select the high toxic commercial products against F. occidentalis. Five insecticides containing active components (pyriproxyfen+spinetoram, abamectin, spinosad, acetamiprid, and chlorpyrifos) were selected among 17 commercial products. These five selected insecticides gave different toxic properties to the natural enemy, O. laevigatus. Especially, abamectin and spinetoram gave relatively low toxicity to the natural enemy compared to organophosphate or neonicotinoid. Furthermore, the five selected insecticides were assessed in their residual toxicities against O. laevigatus. Organophosphate and neonicotinoid insecticides showed relatively longer residual toxicity compared to abamectin and spinosads. Indeed, abamectin or spinetoram did not give any significant toxicity to O. laevigatus after 3 days post-treatment. These residual effects were further supported by the assessment of the chemical residue analysis of the insecticides using LC-MS/MS. These results suggest an IPM technology: (1) chemical treatment of abamectin or spinetoram against sporadic outbreaks of F. occidentalis infesting hot pepper and (2) re-introduction of O. laevigatus to the crops after 3 days post-treatment to depress the equilibrium density below an economic injury level.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.313-317
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• 2016

The congener and sympatric species, Grapholita molesta (Busck) and G. dimorpha Komai, are economically important pests against various Rosaceae fruit trees in Korea. In this study, we identified the species from the larvae of these two insects collected from damaged fruits of peach, plum, apple, pear, and quince by using a molecular diagnostic method and compared the distribution ratios of the two species within the fruits of each of these trees. Most (99.7%) of the larvae collected from peach fruits were identified as G. molesta, while all of the larvae found in plum fruits were G. dimorpha. Both species were found in the other three fruits, but G. molesta was significantly dominant in pear fruits. G. dimorpha was more abundant in apple and quince fruits, without any significant difference between the distribution ratios of two insects. The results suggest that development of further realistic strategies is necessary for the management of these two pests in Korean orchards.

• Journal of Apiculture
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• v.32 no.3
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• pp.163-170
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• 2017

Small hive beetle (SHB, Aethina tumida Murray (Coleoptera: Nitidulidae) is a honeybee pest infesting combs and stores inside the hive. Contamination of the SHB on Apis mellifera colonies were firstly noticed on September 23, 2016, in Miryang City, Gyeongnam Province in Korea. After that, on October 5, 2016, we investigated the spatial distribution of SHB inside the hive and outside soil within the apiary. Total of 169 beehives were observed. We found all stages of SHB inside or outside of hives. 61% of hives infested with the adult SHB still had live honeybees whereas hives containing larval SHB did not have bees, implying colony destruction In hives with live bees, infestation density was higher as bee population became higher. Coefficient of dispersions (CD) showed significant clumped distribution of infestation among hives. CDs were much higher inside hive than outside soil. Our results indicates SHB could result in honeybee colony collapse it not managed properly. Also even during October, there are new infestation into honeybee colonies and every stage of SHB could still be able to develop. Further detailed analysis of this insect' adaptation in Koran environment could help guide the management strategies of the invaded new pest of honeybee.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.309-313
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• 2008

In a cultivated field of Salicornia europae in the Jeonam Province, Korea, Scrobipalpa salinella (Lepidoptera, Gelechiidae) which feeds and leads to a serious damage was found. The discovery of this species is to reconfirm its distribution in Korea because the first report by Park and Ponomarenko (2006) was based on a single female and it was collected in a montane area far from seaside where its host plants, halophytes, are planted. For identification, photos of imago and genitalia are given, and the damage by larvae on Salicornia europae are noted.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.328-333
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• 1998

To obtain basic information for establishing a pest control strategy for insect pest management system, changes in the population densities of the black-tipped sawfly(Acantholyda posticalis posticalis Matsumura) and damage patterns in tree growth were investigated in national forests in Hoigok-ri, Kapyung-gun, Kyunggi-do, where the pest control measures were taken. The results obtained were as follows ; 1. The larval density in the soil of the forests where the insecticides were applied have been kept below economic threshold for about 7 years. The density was the highest in the middle of slopes and similar to the level of the early stage of the insect outbreak. 2. After the pest control by insecticides, reduction in tree height and diameter growth lasted for 2-3 years in trees defoliated by over 70%. 3. The diameter growth of the trees damaged by black-tipped sawfly recovered faster in upper stem than in the lower. 4. volume growth of the trees defoliated over 70% by the insect decreased for three to four years. The volume loss of trees defoliated by 70% and 90% was 19.6% and 54.0%, respectively. 5. Maintaining the rate of defoliation below 50%, which is the economic threshold, by chemical control measures had an effect of reducing the tree volume loss by $40m^2/ha$ as compared with a stand defoliated by 90%.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.129-150
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• 1985

The present investigation was conducted to provide a systematic approach necessary to establish an integrated insect pest management program of barley in Korea. Some ecological surveys on insect pests of barley have been undertaken at the field of Experimental Station, Ky$\check{o}$ngbuk Provincial Office of Rural Development as a fixed point survey area, and at 23 localities for round survey throughout southern and central Korea from 1983 to 1984. Previously known insects injurious to barley in Korea were revised and the population dynamics of 10 dominant harmful species were analyzed according to either 24 localities or 25 cultivars respectively by using several sampling methods of net sweeping, black light traps, yellow water pan traps and visual counting. As the results, a total of 94 species belonging to 77 genera under 32 families are known to be injurious to barley, among them 20 species are newly added here. In the population density level, the dominant species were disclosed as Laodelphax striatellus (43.1 %), Macrosiphum avenae(27.0 %), Rhopalosiphum padi(6.5 %), R. maidis(5.4 %), Psammolettix strialus(2.7 %), Chlorops oryzae(2.2 %), Agromyza albipennis(2.1 %) Phyllotreta nemorum(1.4 %), Chaetoenema cylindrica(1.0 %), Dolycoris baccarum(1.0 %) in order. For the general abundance of major insect pests, it was highest in the cultivar P'aldal whereas lowest in Milyang #22. There were tendencies that Psammotettix striatus, Dolycoris baccarum, Phyllotreta nemorum and Chaetocnema cylindrica represented a maximum increase in the beginning of June, while Chlorops oryzae and Agromyza albipennis showed in the middle of May but aphids were in the end of May. In the dominance of natural enemies, Nabis stenoferus occupied 21.4 % and Propylaea japonica 9.6 %.

• Landscaping Tree
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• s.90
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• pp.19-21
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• 2006

전국어디서나 쉽게 볼 수 있는 개나리는 봄이 오면 노란 꽃망울을 피워 우리의 가슴을 설레게 하는 봄의 전령이다. 노란 꽃은 병아리와 비유되어 어린 아이의 귀엽고 깜찍한 모습과 비교되는 우리와 매우 친숙한 나무이다. 전국의 어디서나 음지, 양지, 모두에서 잘 자라며 추위와 건조에도 매우 강하고, 공해와 염기에도 강하여 울타리 조성용, 조경수, 관상수 등으로 널리 보급되어 우리의 생활주변에 자리 잡은 나무이다. 개나리나무에 개나리잎벌, 좀검정잎벌, 식나무깍지벌레 등이 기생하여 피해를 주고 있어 이들에 대한 간략한 생태 및 방제법을 기술하고자 한다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.257-263
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• 2003

방제는 재배작물에 발생하는 병충해를 최소화하여 농산물의 품질을 향상시키고 생산성을 증대시키는 중요한 관리 작업이며, 작물을 재배하는 동안에 여러 번 작업해야하며 노동 강도가 크고 농약중독 위험 때문에 농민이 기피하는 작업이다. 방제 방법에는 화학적 방제와 생물학적 방제, 농업적 방제, 기계적 방제 등 여러 방법이 있다. 화학적 방제는 잡초나 해충, 균의 밀도가 경제적 피해 수준 이하에서 유지되면서 더욱 확산되지 않도록 천연 또는 인공 화학물질을 이용하여 병해충이나 잡초를 억제는 방제방법으로 현재는 물론 가까운 미래에도 주를 이룰 것으로 예상된다. (중략)

• Landscaping Tree
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• s.85
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• pp.9-11
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• 2005

봄이면 항상 아지랑이 속에 나울나울 봄바람과 함께 분홍빛 자태를 들어내며 겨우내 추웠던 흔적을 지우고 세상사 으뜸은 ''나pos; 라고 소리치는 진달래! 우리의 동산을 채우고, 우리집 마당을 채우고, 길가의 언덕까지 채우고, 내 마음의 허전함을 채우는 철쭉, 진달래 등 종류도 다양하고 품종도 다양하다. 정원수와 조경수로 많이 선호하며 몇몇 지방에서는 5월이면 철쭉 축제도 개최하는 곳이 있다. 하지만 이 아름다운 나무를 못 살게 구는 몇몇 병해충이 있으니 진달래방패벌레, 독나방, 극동등애잎벌, 철쭉떡병 등이 대표적인 병해충이다. 이들에 대한 피해현상과 방제법에 대하여 간단히 소개하고자 한다.