• Korean journal of applied entomology
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• v.42 no.1
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• pp.81-84
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• 2003

Biological control of aphids using "banker-plants with the parasitoiid, Aphidius colemani Viereck (BPAC)" was carried out on cucumber in greenhouse. The BPAC consisting of barley seedlings infested with Schiraphis graminum (Rondani) enhanced the early establishment of Aphidius colemani in the greenhouse and prolonged the control of Aphis gossypii on May 8, 2001 The BPAC was placed in the greenhouse at transplanting at the rate of 1 per 30 m2 of cucumber. Although good control effect was gained until early August after placing banker plants on May 9, the effect after then because of high temperature. The aphid population on cucumber in control plots reached to a peak on June 26, and decreased because of entomopathogenic fungus for rainy season of July, and increased again to a very high population on August.

• Korean Journal of Agricultural Science
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• v.28 no.1
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• pp.18-26
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• 2001

Application of the Asian ladybird (Harmonia axyridis) to control several species of aphids in the plastic green houses in mind, control effects of aphid populations regulated by the Asian ladybird were observed. The green peach aphid, the turnip aphid, and the cotton aphid were present on mustard plants, Angelia utlis, ornamental kales, and egg plants at greenhouses in spring, summer, and winter. Adults and larvae of the Asian ladybird used in experiments were collected from aggregated sites at Taejon in the autumn and reared on the cotton aphid in the laboratory. In winter, more number of adults and larvae of ladybirds than in other seasons were needed to control aphid population in successively double plastic greenhouses with supplied subterranean water for keeping warmth. In spring and summer, it was possible to keep the aphid populations low when necessary by manipulating ladybird populations according to the density of aphids. On the other hand, the innate increasing rate of aphid, the aphid population density at the time of applying ladybird, the predacious ability of ladybird at specific developmental stages, and needed periods should be taken into account to control aphids. In addition, the environmental factors, for example, optimum temperature and humidity should be considered to be biologically effective when ladybirds are released to greenhouses.

• Korean journal of applied entomology
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• v.50 no.1
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• pp.79-82
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• 2011

Biological control of Aphis gossypii by natural enemies was carried out in watermelon from April to June. Aphidius colemani was released 3 times at rate of $2/m^2$ to control A. gossypii(April 24, May 8, and May 22 in 2007). In A. colemani-released plots, A. gossypii showed low population density of < 0.6 per leaf with the highest parasitism of 57.2%, and 2.0~10.6% in the percentage of leaves with aphids. In control, the population of A. gossypii kept on increasing from early May and reached 653.2/leaf on may 29.

• Korean journal of applied entomology
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• v.13 no.1 s.18
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• pp.25-31
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• 1974

This survey was aimed to accumulate basic data of aphid population at the Horticultural Experiment Station at Suweon. The yellow pan traps were setted at five locations (Fig.1.), and ran from May 1 to October 31. 1970. About one hundred and twenty species of aphids were trapped, including 24 species of plant vims vectors. Of these, dominant species were as follows: (Asterisk shows virus vector) Aphid species No. of catches * Aphis spiraecola PATCH 2,635, * Aphis craccivora KOCH 2,377, * Myzus persicae SULXER 2,111, Capitophorus hippophaes javanicus H.R. LAMBERS 2,051, Anoecia fulviabdominalis SASAKI 1,480, * Aphis gossypii GLOVER 867, * Macrosiphum avenae FABRICIUS 859, Cervaphis quercus TAKAHASHI 692, * Lipaphis erysimi KALTENBACH 645, Pleotrichophorus chrysanthemi THEOBALD 489, The above 10 species consisted $76.5\%$ of total catches and the 24 vector species consisted $55.5\%$. The curve of the seasonal occurrence of flying aphids at Horticultural Experiment Station shows bimodal, typical for the temperate region. The total number of trapped aphids at the Station from May to September, 1970, were less than that of average yearly catches at the College of Agriculture from 1967 to 1970. Thi, low numbers at Horticultural Experiment Station may attribute to the frequent spraying of insecticides from Spring to Summer on growing crops there. But the aphids population increase suddenly in the middle of October. This might be resulted from cease of insecticide applications and migration of aphids from summer host to winter host plants.

• Korean journal of applied entomology
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• v.7
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• pp.5-13
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• 1969

Present system of seed potato production in Korea has several weak points and consequently has difficulties in covering annual shortage of 60,000 tons of seed potatoes. The author has an opinion that this so called 'High land system' of seed potato production adopted by the Government should be replaced by the 'Coastal area system' which is proposed by the author and has many advantages over present 'High land system'(2). In coastal areas where enormous acreage of rice paddies are spread, mostly around the villages. the primary host plants of the vectors are found. Therefore, the only source of aphid vectors are limited to the villages. The farmer's houses scattered more sparsely also have minor importance. In the previous paper(2), the author reported that the aphid vector populations were lower in the coastalareas than at Taegwanryong where the Alpine Experiment Station for the production. of seed potatoes is located. However, the number to vectors at Okku showed rather high density, where the trap was placed at the distance of 200 m from a village where peach and Hibiscus trees, the primary hosts of Myzus pesrsicae and Aphis gossypii were grown. To clarify the flight distance from the source of the aphid vectors, a trial was carried out in the Kwanghwal area, Kimje-gun, Cholla-pukto. on the western coast. 13 traps were placed at four directions and the distances between the traps were 250 m. (Fig. I) The traps 'Were operated from June 21 to October 31. The results are shown in Table 1. A total of some 70 species of aphids were found, including 5 speceis of potato virus vectors. The vectors are as follows: I. Myzus persicae (Sulzer) 2. Aphis gossypii Glover 3. Aulacorthum solani (Kaltenbach) 4. Lipaphis erysimi (Kaltenbach) 5. Macrosiphoniella sanborni (Gillette) Out of a total of 12,797 aphids, 5,187$(48\%)$ vectors were found. The trap catches at the 13 locations are shown in Fig. 2 and the numbers of the vectors at each location for each vector, except Macro-siphoniella sanborni. of which only a single individual was caught, are shown in Fig. 3-6. Number of vectors at C (3,279) (Centre of the village) is considerably higher than that at Suwon (763); however, EI. SI. WI and NI. where the distanecs from Care 250 m, showed lower numbers of vectors than that at Taegwanryong (347). The number of vectors at NI was rather than at the other 3 locations at the distance of 250m from the village. This was because C was in the southern part of the village. Consequently NI was much closer to the village than the other 3 locations of the same distance from C. Numbers of catches of the most important vector. Myzus persicae, are shown in Fig.3. The distribution pattern is typical except $S-2\;and\;W_3$, where several farmer's houses were found. If only the rice paddies were found in these locations. the numbers of the vectors would be small as the distances increase. Numbers of catches of the other 3 vectors are shown in Fig. 4-6. From these results. the author has drawn the following conclusions: 1. The aphid vector sources at the rice paddy belt in the western coast are the villages. 2. The vector densities at the locations where the distances are 250 m from the centre of the village are lower than that at Taegwanryong. 3. The vector densities become gradually lower as the distances from the centre of village increase. However. depending on the host plant situation at each location, the vector densities are variable. These minor sources of aphid vectors may be eliminated so that seed potatoes can be grown. 4. Thus. under the direction of specialists, fields suitable for seed potato production can be found in the coastal areas.

• Korean journal of applied entomology
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• v.40 no.1
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• pp.45-45
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• 2001

Development and predation of an aphidophagous gall midge, Aphidoletes aphydimyza (Rondani) , on the green peach aphid, Myzus persicae Sulzer, were studied under laboratory and greenhouse conditions. The developmental threshold temperature of the gall midge larvae was estimated to be $13^{\circ}C$. Larval and total developmental periods were 5.3 and 29 days at 25 $\pm$$2^{\circ}C$. The gall midge attacked more aphids as increasing density of peach aphids, and consumed 4 out of 10 peach aphids per day in a petri dish (9 cm in diameter) at maximum. In green house, the gall midge could control the density of the green peach aphids efficiently with a delayed density dependent-like pattern.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.379-386
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• 2013

Aphidius colemani and Orius laevigatus aree natural enemies of the control cotton aphid and western flower thrips, which are the major pests of cucumber plants. We evaluated the low toxicity of 47 fungicides against A. colemani and O. laevigatus, and we investigated the simultaneous effect of the natural enemies with fungicide of low toxicity on the pests. The toxicity of DBEDC, hexaconazole, pyraclostrobin, tribasic copper sulfate, triflumizole, chlorothalonil, flusilazole, folpet, carbendazim+diethofencarb, cymoxanil+fenamidone and trifloxystrobin to A. colemani mummies was more than 50% and to O. laevigatus was low toxic. Among the fungicides with low toxicity, azoxystrobin 20% WP was selected because it could be used simultaneously with A. colemani and O. laevigatus and as a fungicide to control powdery mildew and downy mildew. In 2011, the densities of western flower thrips and cotton aphid increased rapidly in early-May in Gongju and Cheonan, Chungnam Province. When azoxystrobin was used at an interval of 10 days in spring, A. colemani and O. laevigatus were released at an interval of 7 days at the early occurrence of the pests. The natural enemies decreased the densities of the pests; the maximum number of A. colemani mummies was 18 per lower leaf, and the maximum number of O. laevigatus was 0.5 per flower. Azoxystrobin did not influence the densities of A. colemani and O. laevigatus. The results show that the selected fungicides can be used with A. colemani and O. laevigatus for the intergrated pest management of cotton aphid and western flower thrips in cucumber polyvinyl house cultivation.

• Korean journal of applied entomology
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• v.25 no.3 s.68
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• pp.129-132
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• 1986

Colonizing aphid species on Chinese cabbage, radish, red pepper and cucumber and their seasonal fluctuations were investigated without insecticide treatment during $1982{\sim}1984$ at an experimental farm in Suweon. The major species among the colonizing aphids in each crops were Myzus persicae (Sulzer) and Lipaphis erysimi (Kaltenbach) on Chinese cabbage and radish; M. persicae (Sulzer) and Aphis gossipii Glaver on red pepper; and A. gossipii Glover on cucumber, respectively. Over 200mm of rainfalls within a 10-day period reduced the aphid populations drastically. Relative abundance of the two major aphids on Chinese cabbage and radish, and on red pepper showed inverse relationships between the spring and autumn densities within the same year.

• Korean journal of applied entomology
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• v.20 no.2 s.47
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• pp.112-116
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• 1981

This study was conducted to investigate the seasonal occurrence of aphids and to evaluate their efficacy in the field for the control of some aphids on soybean when Carbofuran, Disulfoton and Ortran were applied infurrow at the planting time in 1976. Foxglove aphid (Aulacorthum solani) and soybean aphid (Aphis glycines) were dominat species in soybean field and there were two peaks in the year. The patterns of occurence of aphids were different between in field and yellow-pan. Carbofuran and Disulfoton showed a good effect for the control of aphids but Ortran was less effective.

• 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.