• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.10-17
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• 2013

History of Instream Flow Incremental Methodology (IFIM) Following the large reservoir and water development era of the mid-twentieth century in North America, resource agencies became concerned over the loss of many miles of riverine fish and wildlife resources in the arid western United States. Consequently, several western states began issuing rules for protecting existing stream resources from future depletions caused by accelerated water development. Many assessment methods appeared during the 1960's and early 1970's. These techniques were based on hydrologic analysis of the water supply and hydraulic considerations of critical stream channel segments, coupled with empirical observations of habitat quality and an understanding of riverine fish ecology. Following enactment of the National Environmental Policy Act (NEPA) of 1970, attention was shifted from minimum flows to the evaluation of alternative designs and operations of federally funded water projects. Methods capable of quantifying the effect of incremental changes in stream flow to evaluate a series of possible alternative development schemes were needed. This need led to the development of habitat versus discharge functions developed from life stage-specific relations for selected species, that is, fish passage, spawning, and rearing habitat versus flow for trout or salmon. During the late 1970's and early 1980's, an era of small hydropower development began. Hundreds of proposed hydropower sites in the Pacific Northwest and New England regions of the United States came under intensive examination by state and federal fishery management interests. During this transition period from evaluating large federal reservoirs to evaluating license applications for small hydropower, the Instream Flow Incremental Methodology (IFIM) was developed under the guidance of the U.S. Fish and Wildlife Service (USFWS).

• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.2
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• pp.115-125
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• 2022

In this study, we investigated the developmental characteristics and genetic diversity of seven populations of two-spotted crickets (Gryllus bimaculatus De Geer, 1773 (Orthoptera: Gryllidae)) raised in South Korea. Regarding the developmental characteristics of the species, we observed no statistically significant difference in the weight of the nymphs in the six populations we tested. After molting, although weight differences were observed between the populations in each stage of the developmental period, the average weight for each developmental stage was constant. We also analyzed mitochondrial COI gene sequences (DNA barcoding region) of the reared crickets collected from five insect farms and two national insect rearing facilities and the resultant sequences were analyzed together with the 12 sequences from foreign countries specimens obtained from public data. We detected six haplotypes from 111 specimens, indicating a low intraspecific genetic distance (~1.8%). The most dominant haplotype was overwhelmingly haplotype 1, which was found in all South Korean specimens and four specimens from China, Indonesia, and Germany. These findings indicate that the low genetic diversity of South Korean specimens can be explained by the fact that the G. bimaculatus population imported for feed from Japan in the early 2000s became a maternal group that spread throughout cricket farms in South Korea. In order to breed healthy cricket strains, it is necessary to increase genetic diversity by importing them from other countries through appropriate quarantine procedures.

• Journal of Sericultural and Entomological Science
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• v.32 no.2
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• pp.94-100
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• 1990

Yongchonppon, one of the native varities, is the highest clod resistant. For its practical use, feeding test has been implemented in the ordinary rearing and in the branch rearing 1987 through 1988. The results are summarized as follows. 1. The feeding of Yongchonppong at the 4th and 5th instar made 5% decrease in spring and 10% decrease of cocoon yield in autumn, respectively, while cocoon shell ratio was a little less and percentage of raw silk was a little high, as compared to the feeding of Kaeryangppong. 2. The feeding of Yongchonppong at the 4th instar only showed nearly same nearing result as the feeding of Kaeryangppon. 3. In case of the feeding of yongchonppong at the 4th instar and early stage of the 5th instar, cocoon yield and percentage of raw silk marked 96% and 97-98% of Kaeryangppong. 4. The total nitrogen and crude protein of Yongchonnppong was less, while the total carbohydrate, crude ash and crude fat were high, as compared to those of Kaeryangppong. It had more phosphate and boric and less manganese than Kaeryangppong. 5. The leaf aereal weight of Yongchonppong was 1.57g/dcm2 and the leaf thickness was 113$\mu$. The moisture reducing rate marked 41.3% after three hour exposure to the air.

• Journal of Sericultural and Entomological Science
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• v.51 no.1
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• pp.1-8
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• 2013

This study was conducted for investigation of habitat and development of indoor-rearing conditions of peacock butterfly, Inachis io (Linnaeus). Three different region, Mt. Kwangduk-san, Mt. Hae-san and Mt. Taebaek-san in Kangwon-do, was selected for investigation of domestic distribution and ecological environment of peacock butterfly. In result, there are many butterflies in the only two region, Mt. Kwangduk-san and Mt. Hae-san. On 16th April, 4 overwintered butterflies were observed in Mt. Hae-san. At the end of June and early in July, 51 individual next generation's butterflies were observed in Mt. Kwangduk-san and Mt. Hae-san. For development of indoor-rearing conditions, collected each 15 male and female peacock butterflies was reared in a room condition. Female butterflies laid eggs in the egg cluster on the underside of host-plant's leaves, Urtica angustifolia Fisch., in the ovipositioning room. We took 11 egg cluster with average $404.6{\pm}23.6$ eggs. Hatchablity of eggs was 92.3%, and the eggs hatched within $5.1{\pm}0.9$ days from the day of oviposition under high temperature, long day condition($25^{\circ}C$, 14L:10D). The larval period was $18.3{\pm}1.0$ days under high temperature, long day condition($25^{\circ}C$, 14L:10D), showing 81.0% pupal ratio. The head width of each developmental larval stage were $0.37{\pm}0.01mm$(1st instar), $0.66{\pm}0.02mm$(2nd instar), $1.07{\pm}0.05mm$(3rd instar), $1.81{\pm}0.07$(4th instar), $2.76{\pm}0.08$(5th instar). The pupal period was $8.4{\pm}0.6$ days, and the emergence rate was 87.5%.

• Korean Journal of Ichthyology
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• v.26 no.1
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• pp.34-41
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• 2014

The present study describes the spawning ecology and early morphological development of Hemitripterus villosus. The natural spawning ground consisted of bedrock and pebbles was the intertidal coast at Taean (Chungnam) and its depth was about 5~10 m. Spawning period was mainly from the end of October to December, when the water temperature and salinity were $6.0{\sim}15.8^{\circ}C$ and mean 32.0‰, respectively. There were no difference of the body shape and color between female and male of Hemitripterus villosus, however its reproductive organs showed clear differences. The male had tube shaped genital papilla, which was connected with testis, and the female had seminal recepacle, which was the lower part of oviduct connected with ovary. Genital papilla of male came out of its body at spawning period and then male copulated. After copulation, female stored the sperm in its seminal recepacle and fertilized when it spawned. Fertilized eggs were reached 8 cells stage after fertilization at rearing water temperature $8.2{\sim}14.9^{\circ}C$. At 29 hours after fertilization, it reached morula stage, and at 146 hours after fertilization, its embryo was clearly formated. Hatching was begun from 1,488 hours (62 days) after fertilization with $8.2{\sim}14.9^{\circ}C$ water temperature. The newly hatched larvae were 12.99~15.46mm(mean $14.16{\pm}0.65$ mm) in TL (Total Length), and its mouth and anus were open. At 7 days after hatching, its yolk sac was completely absorbed and the myotomes were 15+25=40, measuring 15.23~15.54mm(mean $15.39{\pm}0.22$ mm, n=5) in TL. At 75~80 days after hatching, it was measured mean $30.06{\pm}0.76$ mm in TL, and it had reached the juvenile stage with the complete set of fin rays.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.36-36
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• 2003

In the present study, growth performances of the offspring from selected brood line were compared to those of the offspring from non-selected brood line of red sea bream. Offspring groups were mass produced separately from two brood lines, selected and non-selected Korean strain. Selected brood line have been selected by fish size for four generations (upper 5∼30% per generation) and non-selected brood line is the second generation of wild population at south sea in Korea. There's no significant difference in body length between offspring from selected and non-selected brood line during early growing stage (until 96-days old). However, offspring from selected brood line had superior body weight growth than offspring from non-selected brood line. At sea cages rearing trials with communal stocking, Offspring from selected brood line showed significantly better performance in body weight, body length, weight gain, specific growth rate and feed consumption (but not in feed conversion ratio) than offspring from non-selected brood line. At 24 months old, offspring from selected brood line grew faster 1.10 times in body length and 1.41 times in body weight than offspring from non selected brood line. The response to selection when compared to a non-selected line is on average of 10% in weight per generation at 24 months old.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.2
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• pp.165-168
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• 2008

The hybrid ($CSR2{\times}CSR4$) eggs treated with acid were taken up for the study with an objective to develop long-term preservation schedule. The hybrid eggs obtained with two mating duration (3 h and 6 h) and oviposition period (6 h and 24 h) with two age groups of eggs (24 h and 36 h) were treated with Hydrochloric acid. These eggs were subjected to preservation at $5^{\circ}C$ in single step refrigeration and at $5^{\circ}C$ and $2.5^{\circ}C$ under double step refrigeration from $10{\sim}120$ days. These eggs were released from the cold storage as per the specified durations and incubated at standard conditions and allowed 2 h for hatching at 450 lux light. Hatchability was found to be significantly higher or on par with the control in three treatments (T1, T2 and T4) where the eggs are preserved continuously at $5^{\circ}C$ up to 30 days. However under double step refrigeration, hatching was not significantly affected in 20+60 day's combination of T1 treatment up to 80 days. Bioassay studies of the promising treatment i.e.. T1 with (20+60) days indicated that early stage loss and cocoon yield was found to be on par with the control. Hence this treatment was recommended for preservation of acid treated new bivoltine hybrid layings. Details of the hatchability and rearing performance of long term preservation of acid treated eggs are discussed.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.295-301
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• 2015

We investigated mycophagous ladybird, Illeis koebelei from 12 species of plants infected with powdery mildew in Gyeonggi-do, Korea. The pear tree, Pyrus ussuriensis var. macrostipes (Nakai), was most preferred by I. koebelei. This species was found from early July to early November in pear orchards. There was no entomophagous trace in the gut of I. koebelei without powdery mildew spores in a microscope. All stages except egg and pupa are obligate mycophagous, and the feeding potential is ranked as follows: fourth instar, adults, third instar, second instar, and first instar. Feeding amounts of each stage of I. koebelei were 45.6, 144.4, 372.2, 628.1, and $473.7mm^2$ of cucumber powdery mildew per day. Fourth instar larvae showed highest consumption of cucumber powdery mildew. Developmental periods of four larval instars and adults feeding cucumber powdery mildew were 1.2, 2.3, 2.3, 4.6, and 37.7 days, respectively, at $25^{\circ}C$. In this study, we could not determine the feeding potential of I. koebelei against the cucumber powdery mildew; therefore, and further studies are required to elucidate the potential of this species as a biological control agent, e.g., mass rearing, selection of low toxic chemical agents for Integrated Pest Management (IPM), and control techniques against powdery mildew in agro-ecosystems.

• Korean Journal of Ichthyology
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• v.26 no.3
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• pp.159-170
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• 2014

The effect of substances discharged from copper alloy mesh on the survival rate, growth, and health status of Sebastes schlegeli was investigated. Survival rate of experimental group was 10% higher than control group. There was no significant difference in weight gain and SGR between control group and experiment group (P<0.05). Glucose concentration was lower in the experimental group than that in the control group. GOT and GPT contents did not show significant difference during experiment except for the early three months of experiment (P<0.05). Ammonia concentration had not significantly changed in the experimental group, but it had increased until four months of experiment and then decreased afterwards in the control group. TCHO had decreased in the experiment group compared with that of control group. Copper and zinc contents had increased as compared with those in the initial stage of experiment with no significant difference between experiment group and control group (P<0.05). Histological analysis for the liver revealed that liver tissues were not particularly different from those in control group. There were no significant differences in survival rate, growth, and hematological characteristic between control group and experiment group (P<0.05). Though copper and zinc were accumulated as compared with those during the initial stage of experiment, the levels were lower than permissible levels for copper and zinc. As a result, copper alloy mesh would not adversely affect on the survival rate, growth, and health status of fishes.

• Journal of Sericultural and Entomological Science
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• v.17 no.2
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• pp.141-149
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• 1975

Silkworm is known to be damaged under the unfavorable environmental conditions. Recently, it has been often argued that nicotine is a main factor to affect the silkworm nutritional balance and to result in decrease of quantitative characters, and unbalance of larval nutrition. Especially in spring season, there is tendency to produce nicotine damage to silkworm fed with the mulberry leaf near to tobacco field early cultivated in mulching system. In these connections, the trial was made in the different pots placing by the different distance 10rn, 20m, 40m, and 60m in the direction of east-north from the tobacco field. Location of pot near to the tobacco fold is 40m below the tobacco Held and gradually higher than the tobacco field by 10 degree of slope. In addition, when the mulberry field is divided into two areas from the east-south to west-north, southern east zone is lowering down below 10 degree of slope and has 36％ of east-south wind, 21％ of south-east wind and 16％ of south wind, etc. Pots are left on the mulberry field from the completion of lower part leaf harvest to just before upper part leaf harvest is completed for 32 days. Then silkworm at 4th-5th stage was fed with the leaf grown during the period and larval characters are statistically analyzed. The results are summarized as follows： 1. 10-40m distant pot statistically at the same level has the longest larval duration and 60m distant pot is. not significant at 5％ level. Whole larval duration has same tendency as in the 5th larval duration. 2. Percentage of delayed molting larvae at the 5th stage is increased in 10m distant pot and there is no significance statistically in other pots, as compared with that of control. 3. It is not showed that there is no damage to mortality of the old larvae in 60m distant pot. 4. 10-20m distant pot produces a low pupation and others are at the same level statistically at 5％ significance, 5. It is showed that nicotine damage is occurred in single cocoon freight and cocoon shell weight up to 60m distant pot, rather higher damage in cocoon shell weight than in single cocoon weight. 6. It is showed that cocoon yield from 10, 000 molted larvae including double cocoon is decreased up to 40m distant pot far from the tobacco field in which 40％ of cocoon yield in 10m distant pot by 7kg, 26％ of cocoon yield in 20m distant pot by 3.9kg, 24％ of cocoon yield in 40m distant pot by 3.6kg, and 12％ of cocoon yield in 60m distant pot by 1.8kg, as compared with control. However, there is no significance statistically at 5％ level in 60m distant pot. With these above results, it is concluded that nicotine da mage could be occurred in cocoon yield and cocoon quality up to 60m distant far from the tobacco field.