• Korean journal of applied entomology
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• v.44 no.3 s.140
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• pp.231-235
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• 2005

This study was conducted to obtain the optimal spray time for Pseudaulacaspis prunicota (Maskell) (Homoptera: Diaspididae) in early seaon in Jeju. Oviposition time of overwintered females and activity of hatched nymphs of P. prunicola were monitored, and the phenology data were compared with the outputs estimated by a degree-days model of P. pentagona (Targioni-Tozzetti)). Overwintered females of P. prunicola began to lay eggs from mid to late April, and the eggs started to hatch from early May followed by the active migration of the hatched nymphs during mid May. The phenological events of P. prunicola in early season were likely comparable with those of P. pentagona reported in southern Korea and in central Japan. A degree-day model, which predicts the proportion of >50% hatched egg batches of P. pentagona (y=1[exp(-(-a+bx))]; y, proportion; x, degree-days based on $10.5^{\circ}C$ from 1 January; a=-18.80 and b=0.073), accurately described the migration time of P. prunicola hatched nymphs. Thus, it is considered that the degree-day model can be used for predicting the optimal spray time for P. prunicola in early season.

• Journal of Aquaculture
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• v.10 no.4
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• pp.473-483
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• 1997

Yolk resorotion and commencement of external feeding in larvae of red spotted grouper, Epinepheus akaara were studied to understand the high mortality of larvae. Consumption of yolk was higher than that of oil globule for the first 24hs after hatching. The resorption rates of yolk and oil globule increased with the increase of temperature. The time yolk was comsumed up to 99% was 84hs after hatching in 23~$25^{\circ}C$,72hs at ~$27^{\circ}C$, and 60hs in 29~~$31^{\circ}C$, while the time for oil globule was 96hs in 23~$25^{\circ}C$, 84hs at $27^{\circ}C$, and 60hs in 29~$31^{\circ}C$. The relationship between mouth openning time (Y) and water temperature (X) was repersented as a linear regression, Y=-2.53X+118.4, (r2=0.89). In 72~96hs after hatching, upper jaw sizes of the larvae reached around 0.114 mm. By the time the larvae comsumed most of the yolk and oil globule, and started external feeding. The relationship between upper jaw length (Y) and total length (X) was represented as a linear regression, Y=0.139X-0.165, (r2=0.88). Rotifer was not found in the guts of larvae before 72hs after hatching at $28^{\circ}C$, when larvae resorbed their yolk and oil globule over 99%. But, at 96hs after hatching, about 33% of the larvae had the rotifer in their guts. Delayed feeding experiments revealed that the earlier food supply within 84hs after hatching showed the better survival rates for the larvae. The larvae fed at 96hs after hatching died all within 120hs.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.338-339
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• 2001

대게의 산란은 일본 서ㆍ남해 근해에서 겨울∼봄에 이루어지는 것으로 보고된 바있으나 (Yoshida, 1941; Ito, 1963), 이 결과는 자연산 채집에 의한 생태학적인 방법으로 접근한 것이 대부분이며, 일본의 대게 분포수역과 인접한 우리나라 동해안 울진, 축산 근해의 대게 성숙과 산란에 관한 비교자료는 거의 없다. 또, Lim et al.(1998)은 동해안 대게 유생의 부화실험에서, 부화시기가 12월경이라고 하였는데, 앞으로 지역적인 성숙시기의 차이를 검토해 볼 필요가 있다. (중략)

• KOREAN POULTRY JOURNAL
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• v.37 no.4 s.426
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• pp.72-75
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• 2005

1994년에 제정된 종계장위생관리요령과 1999년에 고시되었던 추백리 방역실시요령이 폐지되고 종계장$\cdot$부화장방역관리요령이 새롭게 만들어져 2004년 12월에 고시되었으며, 이중 검사시기, 검사방법 및 판정기준 등이 올 5월 1일부터 전면 시행될 예정이다. 이번에 제정 고시된 방역관리요령은 종계장$\cdot$부화장의 효율적인 방역관리와 추백리$\cdot$가금티푸스의 사전예방을 통해 양계농가에 건강한 병아리를 공급하기 위함이며, 이 고시에 수록된 주요 내용을 보면 추백리 및 가금티푸스에 감염된 종계군의 종계사용금지, 채혈시기 및 횟수, 종계혈청검사방법(급속전혈평판응집반응법, 효소면역법), 양성계군의 판단기준, 부화장에서 백세미용 알 및 병아리의 거래기록 작성 등이 새롭게 제시된 점이다. 종계장 및 부화장방역관리요령의 시행에 앞서 종계장 및 부화장에서의 살모넬라 감염증에 대한 피해를 최소화할 수 있는 방역관리에 대하여 알아보고자 한다.

• Korean journal of applied entomology
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• v.29 no.1
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• pp.20-24
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• 1990

Studies were carried out to investigate the overwintering densities of spider mites, hatching rate and time of P. ulmi eggs, and seasonal occurrences of spider mites (P. ulmi and T. urticae) in apple orchards of Kyungpook province from 1987 to 1989. Overwintering density of P. ulmi eggs was higher in Kunwi, Andong, Chilgok but lower in Kyungju. Overovintering densities of T. urticae were high in all the regions. With the hatching time and rate for P. ulmi eggs, the first hatching ate was April 14, and the last was May 3, and the average hatching rate was 89.3%. The density of P. ulmi was high from early May to middle July and T. urticae begin to increase rapidly from middle June and then was continuously high upto fruit harvesting time.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2018.06a
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• pp.129-130
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• 2018

• Korean journal of applied entomology
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• v.51 no.4
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• pp.371-376
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• 2012

This study was conducted to predict the hatching time of eggs of Lycorma delicatula, to select an effective environmentally-friendly agriculture material (EFAM) and to evaluate the attraction effect of brown sticky traps for controling of Lycorma delicatula nymph and adults. Eggs hatched 55.9, 26.8, 21.6 days after incubation at 15, 20, $25^{\circ}C$ with 14L:10D condition and the hatching rates of egg were 61.9, 57.8, 30.4%, respectively. At high temperature conditions, egg development periods were shorter and the hatching rate was lower. The relationship between temperature and developmental rate was expressed by the linear equation Y=0.0028X-0.0228, $R^2$=0.9561. The low temperature threshold of eggs was $8.14^{\circ}C$ and the thermal constant required to reach larva was 355.4 DD. According to this relationship, the mean estimated hatching date was $22^{nd}$ May. The effective EFAM was natural plant extract, sophora extract, derris extract to nymph and natural plant extract, pyrethrum extract, sophora extract to adult. Among three colors of sticky trap : brown, blue and yellow, the brown sticky trap was the most attractive to nymphs and adults of L. delicatula over a 2 weeks trial period. It suggested that the brown sticky trap could be a very useful and environment-friendly control method for nymphs and adults of L. delicatula.

• Korean journal of applied entomology
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• v.1
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• pp.51-53
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• 1962

1. 본시험은 이화곤충방제에 유효하다고 인정된 신살충제를 선정하여 이화곤충에 대한 살충효과의 재확인 및 살포적기를 구명코저 시행하였다. 2. 제일화기에 있어서 Diazinon, Lebaycild, Endrin 및 Folidol은 부화 14일전 처리로서도 부화유충의 식입제로서 유효하였고, 부화유충 식입후일처리구에 있어서도 무처리구에 비하여 유효하였다. 3. 제2화기에 있어 부화 21일전 처리구의 유효성은 Detron=Folidol>$\gamma$-dol>Endrin>Dimecron의 순이었다. 그리고 부화 14일 및 17일전과 부화 2일 및 7일후 처리에 있어서도 $\gamma-dol$을 제한 다음 약제들은 고도의 유효성을 나타내었다. 4. 그러나 약제처리시기 사이에는 유의성이 없었다. 5. 본시험은 1회의 시험성적임으로 동일시험이 수회반복되어 살충효과 및 살포적기가 완전히 구명되었으면 한다.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.431-436
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• 2013

Ricania sp. lay eggs into the new twigs of blueberry and suck nutrients causing growth retardation and a sooty mold symptom. This study was conducted to investigate the emergence success and developmental period of overwintered eggs of Ricania sp. under the seven constant temperatures from 10 to $34^{\circ}C$ by $4^{\circ}C$ intervals (14L:10D). We also monitored the emergence time of the Ricania sp. nymph at blueberry by 3 ~ 4 day interval using a modified leaf clip cage. Development times from the overwintered egg to $1^{st}$ nymph were 107.1, 54.5, 33.9, 25.3, 25.1 and 16.7 days and the emergence successes were 23.1, 30.8, 13.8, 21.7, 11.9, and 0.6% at 14, 18, 22, 26, 30 and $34^{\circ}C$, respectively except at $10^{\circ}C$. The developmental periods were decreased with increasing temperatures. First emergence date of the nymphs in the field was between 19 and 22 May, and the average emergence success was 19.6%. The present study might be helpful to establish the management strategy of Ricania sp. based on the biological characteristic.

• 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.