• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.217-226
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• 2006

As the results achieved by the evaluation of toxicities on an aphid parasitoid, Aphidius colemani by 79 pesticides registered as horticultural pesticide and 4 adjuvants far pest control, 6 insecticides including a-cypermethrin, 13 fungicides including metalaxyl-M+mancozeb and 4 acaricides including bifenazate showed low toxicity against A. colemani adult. Low toxicity was showed in all the 4 adjuvants as well. In residual toxicity test from 40 pesticides which showed toxicity more than 50%, A. colemani was safe from 11 pesticides from the 3th day after treatment, 7 pesticides from the 5th day after treatment and 14 pesticides from the 7th day after treatment, respectively. But, chlorpyrifos-methyl, diflubenzuron+chlorpyrifos, etofenprox+diazinone and imidachloprid+chlorpyrifos showed high toxicities reaching 100%, 97.7%, 100% and 100% respectively, even from the 7th day after treatment. To evaluate the control effect by A. colemani against Myzus persicae in a greenhouse, A. colemani was released at parasitoid versus aphids rates of 1:50 and 1:100 when the population of M persicae was 50 per plant. After release, aphids population remained steady for 20 days after release at the level of around 60 aphids per plant. During the investigation, insecticides fur thrips control and fungicides for powdery mildew control were treated, but didn't affect the mummy forming of A. colemani. It may be suggested from these results that the selected insecticides, fungicides, acaricides and adjuvent could be incorporated into the integrated M. persicae management system with A. colemani on greenhouse cultivation.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.431-435
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• 2015

Riptortus pedestris (Fabricius) is one of the important insect pests of leguminous crops, which occurs in most areas of South Korea. It is hard to distinguish each generation in crop fields since not only the longevity of adult R. pedestris is long but also the developmental period is short. Especially, the 2nd generation adults cause enormous damage to soybean while the occurrence time is synchronized with the podding stage of soybean. Controlling the 1st generation of R. pedestris helps to decrease the damage by decreasing the 2nd generation density. This study was conducted to distinguish between the 1st generation and the overwintering generation by using differences in body coloration which is dependent on the day-length during the nymph stage. In addition, the difference was verified by the population dynamics model of R. pedestris. The occurrence time of 1st generation adults could be considered when the summer form is 20% or more. These results will be used for beneficial management decisions to reduce the 2nd generation population.

• Asian Journal of Turfgrass Science
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• v.17 no.1
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• pp.35-44
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• 2003

Popillia quqdriguttata is a serious insect pest in Korean golf courses. The adult feeds on leaves of latifoliate trees and herbaceous plants while the larva feeds on roots of turfgrass. Thus, control of p. quadriguttata adults was tried with registered insecticides in golf courses in Korea. The insecticides used in the experiments were carbaryl + phosalone WP, chlorpyrifos + diflubenzuron WP, chlorpyrifos-methyl EC, deltamethrin EC, etofenprox WP, etofenprox + diazinon WP, etofenprox + tebufenozide EC, fenitrothion EC, imidacloprid SC, pyraclofos WP, and tralomethrin EC. Mortalities of P. quadriguttata were over 95% in carbaryl + phosalone WP, chlorpyrifos + diflubenzuron WP, etofenprox + diazinon WP, and fenitrothion EC at petri dish and in greenhouse. In the field test, corrected mortality of P. quadriguttata was 95.2% and 80.9% in carbaryl 40% +phosalone 20% WP and fenitrothion 50% EC, respectively. Spreading agent enhanced toxic effect of used insecticides to p. quadriguttata adults except carbaryl + phosalon 20% EC. p. quadriguttata adult was firstly observed to feed on leaves of Canna generalis at the Yongwon golf club in Jinhae, Gyeongnam and Prunus ameriaca var. ansu and p. salicina at the Anyang Honest golf club in Gunpo, Cyeonggi. Therefure, host plants off quadriguftata became 29 species of 26 genera in 19 families. Zoysia matreila at the fairway and roughs of Anyang Benest golf club was damaged by p. quadriguttata larvae in Octomber, 2002 and not recovered in April, 2003. Damaged turfgrass became yellowish and wilted and that retarded recovering in the following spring.

• Korean Journal of Agricultural Science
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• v.29 no.1
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• pp.32-43
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• 2002

The peach pyralid moth (Dichocrocis punctiferalis) is reported as import ant pest insect to chestnut fruits in Asia including Korea. For seasonal occurrence of D. punctiferalis in 1996, 1998 and 1999, D. punctiferalis adults were collected by light trap and sex pheromone wing trap in the chestnut orchard. Also, damaged rate of chestnut fruits were examined each collecting site. In 1996, according to examination by using light trap at three different site in Kongju, the occurrence peak of 2nd gene ration of D. punctiferalis adults was early August. Collected individuals after September were cons ide red as 3rd generation. Damaged rate due to maturation type was 26.5% averagely. The order of damaged rate were early, late and middle maturation type as 35.04%, 19.35% and 26.03%, respectively. Using synthetic sex pheromone trap at Kongju, Cheungyang and Buyeo in 1998, occurrence peaks were occurred mid-August to 2nd generation and late September to 3nd gene ration in Kongju. However, from early-August to late-September 5 peaks were occurred sequentially in Cheungyang. Second generation adults were occurred in mid-August and 3rd ones were occurred from late-September to early-October in Buyeo. In 1999, occurrence peaks of 3rd generation were early, middle and late September in Kongju, Cheungyang and Buyeo respectively. Damaged rate were 6.8%, 6.6% and 15.3% in Kongju, Cheungyang and Buyeo, respectively. Damaged rate order due to variety were Eunki, Chukpa, Danpa, Bokpa, Wangjung, Byunggo57, Yuoma at Buyeo and were Chukpa, Dukmyung, Byunggo57 at Cheungyang in 1999. Damage rate of chestnut were different with variety. Eunki and Chukpa in Buyeo and Chukpa and Dukmyung in Cheungyang were more damaged by D. punctiferalis respectively.

• Korean Journal of Plant Resources
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• v.25 no.5
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• pp.596-602
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• 2012

This study was carried out to effect on Growth Characteristics and Yield of Solanum njgrum L. The experimental results are summarized as follows. Germination, growth characteristics and yield of Solanum nigrum Linne collected from southern parts of Korea were investigated. The one fruit weight was the heaviest in Gochang traditional S. nigrum among the collected sites. The number of seeds in one fruit was high in the orders of Gochang traditional sites, Gwangju traditional sites, Suncheon traditional sites and Naju traditional sites. The earliest flowering of Solanum nigrum was observed on 10. August. The plant height, stem diameter, leaf numbers and branch numbers were ranged from 65 cm to 75 cm, 7.1 mm to 8.2 mm, 237 ea to 270 ea and 12 ea to 17 ea, respectively. The fresh weight per plants were ranged from 265 g to 279 g, and yield of biomass were ranged from 1,298 kg to 1,367 kg per 10a. The insect pest numbers of S. nigrum according to the collected sites were showed no significant in this test.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.445-455
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• 2014

The pear sucker (Cacopsylla pyricola) is the most important insect pest in Korea. The hatching rates of overwintered adults laid eggs were observed at 10, 13, 18, and $22^{\circ}C$. The liner model was draw as Y=0.00277X+0.00146(Y=developmental rate, X=temperature) about temperature and developmental rate to eggs. The developmental threshold temperature to eggs was assumed about $-0.83^{\circ}C$. The egg hatching timing over 50% as the accumulated temperature by day maximum temperature $6^{\circ}C$ over from 1st February in 2008, 2009 and 2011 was 429.7, 417.6, and 424.3 degree $^{\circ}C$, respectively, was 3 to 7days before full blooming in pear orchard. On the other hand, the abamectin 1.8EC, lime sulfer, machine oil and 13 kinds of eco-friendly materials were not shown the control effect to the eggs. To mixed stage of pear sucker, the eco-friendly materials over 90% control value were 4 kinds such as a mixture of Azadiractin A+B, Nimbin, Salanin, Meliantriol and Vepol after twice application as 21st May and 5th June in pear growing season, in 2012.

• Korean Journal of Breeding Science
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• v.43 no.1
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• pp.56-61
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• 2011

Brown planthopper(BPH) is one of the most destructive insect pests of rice. The use of genetically resistant cultivars has proven to be a more economical, efficient and environment friendly means to combat this pest. This study was carried out to investigate the relationship between BPH resistant gene, Bph18 and yield components of rice using DH(doubled haploid) lines derived from 'Saenuri'/SR30071-3-7-23-6-1-1-1. SR30071-3-7-23-6-1-1-1 line has Bph18 gene derived from wild species, Oryza australiensis. BPH resistant gene, Bph18 shortened heading days, enlarged culm length and panicle length and reduced ratio of ripened grains of rice. The results indicate that backcrossing breeding is necessary to develop elite cultivars carrying Bph18 gene.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.379-386
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• 2021

Asian gypsy moth, Lymantria dispar asiatica (Lepidoptera: Erebidae), which is an indigenous pest in Korea, a large outbreak has been reported in Gyeonggi-do, Chungcheong-do, and northern Gyeongsangbuk-do from 2019 in forest and nearby downtown areas, causing emotional damage to forests and city dwellers. During the indoor culture of gypsy moth eggs collected in Yecheon, Gyeongbuk in 2021 we found that 79.65% (321/403 of first instar larvae) were died due to Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV) infection. Sequence analyses of 36 gypsy moths collected from 12 regions in Korea using LdMNPV late expression factor-8 (lef-8) and polyhedrin (polh) genes showed a genetic variation of 0.80% and 0.86%, respectively. Comparison to GenBank data showed that the Korean samples were most similar to LdMNPV in Japan, whereas most different to those of Turkey. These results showed a high infection rate of LdMNPV in Korea and LdMNPV is one of the important population regulators of the gypsy moth.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.215-220
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• 2021

To establish the systematic biological control system for various insect pests in strawberry under plastic houses, we were investigated the biological traits of lesser strawberry aphid, Chaetosiphon minus (Forbes), as a target pest. The lesser strawberry aphid is adapted to low temperatures while examining the availability of and selecting useful natural enemies. The development, survivorship and reproduction of lesser strawberry aphid were evaluated at four constant temperatures (10, 15, 20, and 25℃). The developmental periods of the nymphal stages ranged from 41.7 d at 10℃ to 9.8 d at 25℃. The developmental threshold temperature and degree day of nymphal stages are 5.5℃ and 185 DD. The reproduction rate (R₀) was higher at 20℃ (30.16) than at 25℃ (22.38). The 50 % survival rate and maximum longevity of adult females were 31 d and 59 d at 20℃, and 25 d and 36 d at 25℃, respectively. The average progeny per female was 35 at 20℃, and 26 at 25℃. We confirmed that compared to other strawberry aphids under plastic houses, the lesser strawberry aphid is more adapted to lower temperatures. It is, therefore, necessary to commercialize natural enemies such as syrphid flies with high activity at low temperatures.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.522-528
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• 2018

Saemimyeon, a Tongil type, medium-late maturing rice variety, is especially used for preparing rice noodles. Its high amylose content was developed to fit market demands and to be affordable for rice processing industries. One of the high yielding lines, Milyang181 (Hanareum), was used in the final three-way cross of $IR50^*2$/YR18241-B-B-115-1-1 for yield improvement and cultivation stabilization, including disease resistance. YR24235-10-1-3, a high yielding and compact plant type, was selected and named Milyang278 after yield test at NICS (RDA, Miryang) in 2010. It was subjected to regional yield test at six sites in the middle and southern plain areas of South Korea. Saemimyeon heading occurs on August 12 and is a mid-late maturing cultivar, with resistance to leaf blast, rice stripe virus, and bacterial blight (K1-K3a), but it is susceptible to major diseases and insect pest infestation. Saemimyeon showed a high amylose content of 26.7%, with a relatively low KOH digestion value of 3.5, which are key factors in rice noodles and pasta processing. In the local adaptability tests, the yield of Saemimyeon was 7.08 MT/ha-an increase of approximately 106% compared to that of Dasan. Thus, Saemimyeon is suitable for cultivation in the southern and middle plain areas of South Korea.