• Korean journal of applied entomology
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• v.39 no.3
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• pp.135-140
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• 2000

Development and reproduction of the cotton caterpillar, Palpita indica, were investigatedunder different temperatures (15 .O, 17.5, 20.0, 22.5, 25 .O, 27.5, 30.0, 32.5, and 35 .O$^{\circ}$C). Duration fromegg to pre-adult of the cotton caterpillar were ranged from 68.6 days at 175$^{\circ}$C to 19.7 days at 35.0% (3.5times shorter growth period compared with that at 17S$^{\circ}$C). At 15.0$^{\circ}$C, cotton caterpillar eggs developedto the last larval instar but were not able to go through the pupal stage. The lower developmentalthreshold temperatures and degree-days of egg, larva, pupa, and complete development were 13.4, 10.6,11.6, and 11.5"C and 55.3,251.5, 138.3, and 479.8 degree days, respectively. The hatching, pupation andemergence rates were higher at 25.0eC and 27.5"C compared with other temperatures. The survival ratefrom the hatched larva to adult was the highest at 27.5"C. The preoviposition and the adult longevity were11.5 and 30.6 days at 17.5"C and 1.5 and 9.2 days at 35.0$^{\circ}$C, respectively. The mean fecundity perfemales was greater at 25.0$^{\circ}$C and 27.5"C compared with other temperatures. Mean generation time indays (T) was shorter on higher temperature. Net reproductive rate per generation (R,) was the lowest atthe highest temperature as well as at the lowest, and it was 199.1 which was the highest at 27.5"C. Theintrinsic rate of natural increase (r,) was highest at 30.0$^{\circ}$C as 0.148. As a result, optimum ranges oftemperature for P. indica growth were between 25.0-32.5"C .emperature for P. indica growth were between 25.0-32.5"C .t;C .

• Korean journal of applied entomology
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• v.37 no.2
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• pp.171-178
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• 1998

This study was conducted to investigate the effect of temperature on the development of amushroom-infesting sciarid fly, Bradysia sp. (Diptera: Sciaridae). Egg period was 12.1, 7.0, 4.4, 3.4, and3.2 days, larval period was 38.3, 26.5, 13.4, 13.2, 12.7 days and pupal period was 10.4, 7.1, 4.4, 3.3, 3.2days, and total development period from egg to adult emergence was 60.8,40.6, 22.2, 19.9, and 19.1 daysat 10, 15, 20,25, 28"C, respectively. Development threshold temperature (DT) and effective accumulativetemperatures (ET) were 3.8"C, 74.8DD in eggs, 1.2"C, 321.8DD in larva, and 3.1$^{\circ}$C, 76.5DD in pupa,respectively. The number of eggs laid per female was 107.9, 129.7, 131.8, 86.9, and 82.7 at respectivetemperatures. Preoviposition period was 6.6, 4.4, 2.2, 1.3, 1.8 days, oviposition period 1.5, 1.5, 1.1, 1.1,1.1 days, postoviposition period 2.0, 1.1, 0.9, 0.6, and 0.3 days at th'e temperature of 10, 15, 20, 25 and 28"C, respectively. The longevity of male and female at the temperature was 13.3, 7.8, 5.9,4.1, 3.4 days and10.4, 7.0, 4.2, 3.0, 3.3days, respectively. The optimum temperature for hatchability was estimated to the20$^{\circ}$C and adult emergence was highest at 20$^{\circ}$C. Pupation rate was 50.7, 68.4, 84.3, 86.5, 45.4% at 10, 15,20, 25, and 28"C, respectively. at 10, 15,20, 25, and 28"C, respectively.tively.

• Korean journal of applied entomology
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• v.61 no.2
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• pp.335-347
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• 2022

We investigated the emergence patterns of Chilo suppressalis (Lepidoptera: Crambidae) adults using sex pheromone traps in the three northeastern areas, Dandong (40°07'N 124°23'E) (Liaoning province), and Gongzhuling (43°30'N 124°49') and Longjing (42°46'N 129°26'E) (Jilin province), China, in 2020 and 2021. Two times of adult flight seasons were isolated clearly during the rice growing periods in the all areas, in which the first season from mid May to late July, and the second season from mid July to mid September were observed. The adult emergence seasons in the areas at higher latitude were later than that at lower latitude. Using the adult emergence data during the first flight seasons, the second flight seasons were estimated through insect phenology modelling, and compared with the observed data. Temperature-dependent life history models (developmental rate, development completion, survival rate, adult aging rate, total fecundity, oviposition completion, and adult survival completion) were collected or constructed for each life stage of C. suppressalis, in which the data from the four previous studies were used. Those models were combined in an insect phenology estimation software, PopModel, and operated for the observed areas. In the results, the phenology modelling operated with the models based on the data of shorter larval periods in the previous studies estimated more accurately the second flight seasons. In 2021, we investigated the change of damaged hill ratios of rice with observing the adult emergence at Dandong and Longjing, 2021. The increase periods of damaged hill ratios of rice were observed two times during the total rice cultivation season, which may be caused by different generations of C. suppressalis larvae.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.55-55
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• 2011

연안 및 해안공학의 발달과 더불어 부유식방파제의 기능적 효율성이 중요시 되고 있다. 흔히 사용되어오던 착저식방파제는 설치에 많은 시간과 경비가 소요되고 환경 및 생태계에 많은 변화를 줄 수 있으며, 설치 예정지의 수리학적 특성 등의 여건에 많은 제약을 받는 단점이 있다. 부유식방파제는 일본 등의 선진국을 중심으로 활용이 잦아지고 있는 방파제로서 수면 위에 설치되기 때문에 수중 생태계에 미치는 영향이 적은 친환경방파제이다. 또한 기존에 시공된 중력식방파제와는 달리 수심에 제한을 덜 받고, 공사기간이 짧기 때문에 경제적이다. 실제 시공사례로는 2007년 마산 원전항에 완공된 부유식방파제가 대표적이며, 지금까지도 부유식방파제에 대한 여러 연구자들의 관심이 증가하고 있는 추세이다. 방파제뿐만 아니라 우리나라처럼 국토의 면적이 작은 지역에서 증가하는 해상물동량을 소화하기 위해서 부유식방파제 등을 이용한 항만의 시공이 필요한 실정이다. 이러한 부유식방파제의 분석적인 측면에 있어서 수치해석은 파랑과 구조물의 상호작용을 해석하는 데 한계가 있으며, 부유식방파제 단면형상을 정확하게 재현할 수 없으므로, 수리모형실험을 통한 부유식방파제의 연구가 필요할 것으로 판단된다. 최근 기술의 발달로 인한 유동장 해명이 가능해 졌으며, PIV(Particle image velocimetry) 및 LDV시스템은 다양한 분야에서 응용되고 있다. 특히, LDV시스템은 측정하려는 한 지점에 대하여 레이저 빔을 단면(Cross-section)으로 만들고 입자의 산란광을 후방산란(Back scatter)으로 받아서 도플러 효과를 이용, 속도에 대한 주파수를 획득하며, 유속을 측정하는 장비로 매우 높은 정확도와 비접촉식 이라는 장점을 가지고 있다. 또한, PIV 시스템에 비하여 측정시간이 오래 걸리는 반면 데이터를 가공하지 않고 활용할 만큼 높은 정확성을 가지고 있다. 본 연구에서는 수리모형실험을 통하여 단독형, 2열형 및 3열형 부유식방파제의 형상, 흘수 및 거리를 변화시키며 유동장을 수집하였으며, 방파성능에 따른 와의 생성 및 소멸시점에서의 파랑변형과의 관계를 분석하였다. 방파제의 형상과 흘수를 달리하여 수리모형실험을 수행하였으며, 와류의 상관관계를 분석하였다. 또한, 연직 2차원 Navier-Stokes 방정식 모형을 이용하여 수치모형실험을 수행하였으며, 수치모형실험 결과와 수리모형실험 결과를 비교 분석하였다. 후방방파제에서 발생되는 파랑은 입사파의 주기가 길어질수록 상대적으로 커지는 현상을 보였으며, 흘수심이 깊어질수록 전방방파제 입사 면에서 자유 수면이 높게 관측되는 결과를 보였다. 또한, 비교적 장주기파랑에 해당하는 입사파랑의 경우 전달파고비 산정에 있어서 설계기준인 0.5를 대다수 초과하는 반면, 3열형 구조에서는 대부분이 0.5이하로 상당히 높은 방파성능 결과를 나타내었다.

• Environmental Analysis Health and Toxicology
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• v.23 no.3
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• pp.221-230
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• 2008

Chlorpyrifos (CPF) is a widely used organophosphate insecticide. Japanese medaka, Oryzias latipes was selected to investigate the effects of chlorpyrifos on survival rate, hatching rate, reproductivity and histopathological changes. Adult fish were exposed to CPF at concentrations of 20, 40, 80 and $160{\mu}g/L$, and the test duration was 4 weeks. An experiment with eggs was also performed under CPF exposure continued for 7 days covering from the fecundation to end-hatching stages. Survival rate of the adult medaka decreased in CPF $80{\mu}g/L$ and $160{\mu}g/L$ treatment groups compared with control, solvent control, $20{\mu}g/L$ or $40{\mu}g/L$L treatment group. Spontaneous start of feeding significantly decreased compared with the control (p < 0.01) when exposed to CPF at above 40 $\mu g/L$. Total spawning decreased by the 20 or $40{\mu}g/L$ CPF treatment compared with the control or solvent control in the test with eggs obtained from untreated adult medaka, and abnormal eggs increased in those CPF-treated groups. There were certain adverse effects at above $40{\mu}g/L$ determined from liver and gonad histological examinations. The results indicate that CPF has insignificant toxic effects in Japanese medaka at less than $20{\mu}g/L$ in long term exposure.

• The Korean Journal of Malacology
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• v.30 no.1
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• pp.33-40
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• 2014

The age and growth of Gomphina (Macridiscus) veneriformis sampled from February 2006 to January 2007 on the Wonsan coast of East Sea were determined from 3,899 shell. Age of Gomphina (Macridiscus) veneriformis was estimated from the ring on the surface of shell. The relationship between shell length (SL) and shell height (SH) was expressed by the following equation : SH = 0.7405 SL + 0.2227 ($R^2$ = 0.9671), and shell length (SL) and shell width (SW) was highly correlated by the equation : SW = 0.3657 SL + 0.4253 ($R^2$ = 0.922). The relationship between shell length (SL) and total weight (TW) was also expressed by the following equation : $TW=0.4274{\times}10^{-3}{\times}SL^{2.7876}$ ($R^2$ = 0.9591). The main spawning periods was estimated August through fatness index analysis. Based on the monthly variations in the marginal index (MI) of the shell, it is assumed that the ring of this species was formed once a year during the period of July. Growth curves for shell length (SL) and total weight (TW) fitted to the von Bertalanffy's equation were expressed as follows : $$SL_t=70.80(1-e^{-0.217(t+0.367)})$$ $$TW_t=(1-e^{-0.217(t+0.367)})^{2.7876}$$

• Korean journal of applied entomology
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• v.41 no.3
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• pp.205-209
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• 2002

Effects of temperature on the development and reproduction of the Udea ferrugalis Hubner were investigated at various temperatures (10, 15, 18, 20, 23, 25, 27, 30$\^{C}$). The development times of eggs, larvae, prepupae and pupae were shorter in higher temperatures than in lower ones. Egg and pupa did not develop at 10$\^{C}$. The lower developmental threshold temperatures for eggs, larvae, pupae were 9.5, 9.6 and 11.9$\^{C}$, respectively, and their thermal requirements for development completion were 87.9, 200.9 and 119.7 degree-days at the same temperature, respectively. Adult longevity was 25.2 days at 15$\^{C}$, 7.3 at 23$\^{C}$ and 5.3 at 30$\^{C}$. Mean fecundity per female was higher at 20-23$\^{C}$ compared to other temperatures. Mean generation time in days (T) was shorter in higher temperature region. Net reproductive rate per generation (Ro) was lowest at 15$\^{C}$ (138.2) and it was highest at 20$\^{C}$ (265.4). The intrinsic rate of natural increase (r$\_$m/) was highest at 25$\^{C}$ as 0.247. As a result, it was considered that optimum range of temperature for U. ferrugalis growth was 20.0 to 23$\^{C}$.

• Korean Journal of Ichthyology
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• v.30 no.1
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• pp.9-17
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• 2018

This study investigated how the larvae of three winter-spawning fishes are adapted in a cold water environment by examining the morphology, digestive system, and swimming ability of larvae from three winter-spawning species (Gadus macrocephalus, Liparis tanakae, Hexagrammos agrammus). Data were collected at hatching and first feeding. The results were compared with repored data on several non-winter-spawning species. Mean total lengths at hatching (${\pm}SD$) were $4.35{\pm}0.11mm$, $5.26{\pm}0.08mm$, and $7.48{\pm}0.35mm$ for G. macrocephalus, L. tanakae, and H. agrammus, respectively. Three winter-spawning fishes had well-developed digestive tracts after hatching than those of non-winter-spawning fish larvae. Yolks were intact until 5 days post-hatching in all three species, indicating that they had longer mixed-feeding periods compared with fishes spawned during other seasons. G. macrocephalus, L. tanakae, and H. agrammus larvae had superior cruise and burst speeds (measures of swimming ability) than non-winter-spawning larvae. We conclude that the unique characteristics of these three winter-spawning species are naturally selected adaptations under lower water temperature in winter.

• The Korean Journal of Malacology
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• v.24 no.2
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• pp.109-119
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• 2008

In order to investigate the possibility of yearly-harvest, we carried out growth experiment(shell height, meat weight and condition index) for of the artificial oyster spat, which suspended in three different times before the season for natural spat around coastal waters of Gyeongnam Province. Shell growth of spats suspended in June showed higher than those in April and May. In meat weight, the growth of spats was significantly elevated from October, of which significant difference was observed depending on growing farms(Gosung$\geq$80 mm) and October on the meat weight level($\geq$5 g).

• Korean journal of applied entomology
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• v.34 no.3
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• pp.249-255
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• 1995

These experiments were conducted to investigate the life history and the seasonal fluctuation of population density of tea red spider mite, Tetranychus kanzawai Kishida and to observe its natural enemies in the southern area. Under field-cage conditions, tea red spider mite occurred 11~12 generations. The average periods from egg to adult emergence were 8.7~13.1 days in summer and 12.6~24.9 days in spring and autumn. The average longevities of adults were 15.5~21.9 days in summer and 25.1~31.6 days in spring and autumn. The average number of eggs laid per female were 45.1 in summer and 52.6 in spring and autumn. Tea red spider mite population showed two peaks during April-June, and appeared third or forth peak during October-November. The density of all the stages was the lowest in July through August. Tea red spider mites stayed at lower parts of tea plants in March but they moved to upper parts in April though June, and they again moved to lower parts after autumn. Tea red spider mite overwintered as all stages. Adults were the dominant overwintering stage during this stage. The surveyed natural enemies of the tea red spider mite were 7 species including Amblyseius longispinosus (Evans), A. eharai Amitei et Swirski, Anystis baccarun (L), Agistemus fleschneri Summers, Orius sauteri Poppius, Oligota yasumatsui Kistner and Scolothrips sp.