• Korean journal of applied entomology
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• v.40 no.4
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• pp.309-313
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• 2001

Life cycle and host plants of Scotinophara lurida(BURMEISTER) were studied from 1999 to 2001. Egg of S. lurida was oval-shaped with light-gray in color. Nymphs were reddish brown, dark brown, and brown, and the body was 1.19~7.24mm long, depending on their developmental stages from the 1st to the 5th instar. Adults were black and the body were 9.34mm and 8.47mm long in female laid 30.7 eggs in average for its life span. Developmental period was 4.3 days for eggs, and 45.8 days for nymphs. Total 9 host plant species was identified by the greenhouse observation in Chungbuk province.

• Korean Journal of Ichthyology
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• v.26 no.2
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• pp.133-138
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• 2014

We investigated the spacial distribution and species composition of fish larvae during winter season (January 2013~March 2013) in Jinhae Bay, Korea. During the study period, a total of 12 larvae species belonging to 8 families were collected, and the dominant species were Pholis crassispina, Clupea pallasii, Liparis tanakae, Hexagrammos otakii. These four species accounted for 93% of the total number of individual collected. High density and species diversity occurred around Jam-do and eastern area of Chilcheon-do, suggesting that these areas are the main spawning ground of fish larvae in Jinhae Bay.

• Korean Journal of Poultry Science
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• v.32 no.3
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• pp.195-202
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• 2005

Two experiments were conducted to evaluate the effects of dietary salt levels on the performance in laying hens and broilers. In experiment 1, 108 Avian broilers of 21 days age were conducted to evaluate broiler's performance. The broilers were divided into 6 treatment groups with 6 pens (3 broilers/pen), and 134 diets with different levels of salt with 0.25 (control), 0.5, 1.0, 1.5, 2.0 and $2.5\%$, respectively, for 3 weeks $(3\~5 weeks)$. The feed intake was not affected by the treatments. However, moisture content in feces was increased as increasing levels of dietary salt (P<0.05). In experiment 2, 135 ISA Brown laying hens were used to evaluate on performance of laying hens. The dietary supplementation of salt levels were prepared at 0.25 (control), 1, 2, 3 and $4\%$, respectively, for 4 weeks. Feed intake was decreased as increasing the dietary salt levels during the experiment (P<0.05). Particularly, it was lower in $3\%\;and\;4\%$ salt level treatments compared with the control (P<0.05). As expected, water intake was increased as increasing the dietary salt levels (P<0.05). Therefore, the present results could indicate that dietary salt content need to be considered for broilers and laying hens.

• Korean journal of applied entomology
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• v.23 no.3 s.60
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• pp.158-165
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• 1984

These studies were carried out to investigate the bionomics of Gonatocerus sp. y (Hymenoptera: Mymaridae) , an egg parasite of the green rice leafhopper, Nephotettix cincticeps Uhler (Homoptera: Deltocephalidae) under laboratory and field conditions at Gyeongnam Provincial O.R.D. in Jinju from 1982 to 1983. The developmental period of each life stage was observed under four different temperature conditions from $15^{\circ}C\;to\;30^{\circ}C\;with\;5^{\circ}C$ increment. The development from egg to adult at 15^{\circ}C,\;20^{\circ}C,\;25^{\circ}C,\;and\;30^{\circ}C $ was completed in an average of 53, 25, 15, and 12 days and the females laid an average of 28, 48, 42, and 32 eggs respectively, with a maximum of 98. And most of the eggs were laid in the first two days after emergence. The time of adult emergence was determined under $25{\pm}1^{\circ}C$ condition. More than $76\%$ of the wasps emerged in the morning and the rest of them emerged in the afternoon. The average sex ratio between male and female was 1 : 5 when the wasps were developed from fertilized eggs. The longevity of female was greater than that of male when honey and water were provided as food, however, it was not when only water was supplied as food. The average longevities of females were 30 days at $15^{\circ}C$ and 15 days at $20^{\circ}C$ when honey and water were given as food. The peak precent parasitism of Gonatocerus sp. v on Nephotettix cincticeps in fallow fields was observed between late April and early May. The percent parasitism of the wasps In fallow fields was an average of 49\~59.9\% $ in Gyeochang, Namji and $23.2\~36\%$ in Namhae. The parasitic activities of the parasite had four peaks in paddy field, however, the highest peak was observed between late August and early September. The Percent e99 Parasitism of Gonatocerus sp. y was an average of $12.3\%$ on second the generation and $24.6\%$ of third genera lion of Nephotettix cinrticeps.

• Korean journal of applied entomology
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• v.24 no.3 s.64
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• pp.151-156
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• 1985

Apple leaf miner(ALM), Phyllonorycter ringoniella(Matsumura), occurs $4{\sim}5$ generations a year in Suweon; adult emergence peaks being in mid April, early June, early July, mid August, and mid September with the highest one in the 4th generation. Numbers of days required to complete the development(egg to adult emergence) were different with oviposited dates; 43days for late May, $32{\sim}37$ days for June to July, and 39days for early August. ALM larvae oviposited after late August did not emerge and went into diapause. Sites of the infested leaf on the shoot seemed to be somewhat different with the ALM generations; the preferred leaf sites being the 1st-6th leaf for the 1st, the 4th-9th for the 2nd, the 4th-18th for the 3rd or 4th, and the terminal leaves of the first growth shoot or the leaves of the secondary shoot for the 5th generation. Parasites of three families emerged from the mines of ALM in Suweon. The encyrtid (Holcothorax testaceipes Ratzelburg) occurs 4 generations and the eulophids 5 generations a year. A small number of the braconid(Apanteles sp.) occcrred only in September.

• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.859-867
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• 2016

This study was conducted at rearing room to investigate the feeding behavior of fruits in the firefly (Pylocoelia rufa) larvae and the ovipositional characteristics of the adults. As a result, the pear, apple, melon, persimmon, mandarin, grape and peach were shown the feeding behavior of larvae the average 6.40, 3.25, 2.50, 2.20, 2.00, 1.40 and 1.25, respectively. However, the larvae were not shown at all feeding behavior to banana. The hours feeding behavior of firefly larvae was primarily from 8:00 pm until 2:00 am. In addition, the time at which the voracious feeding behavior was until 8:00 pm to 12:00 pm. The 6:00 pm began whisking all the larvae are hiding in the shelter. In the case of the firefly larvae fed only the edible snail, the adults were oviposition an average $49{\pm}6$ eggs. At that time larva stage, adults of the firefly eating the pears, apples, melon and eat edible snail at the same time there were oviposition the $53{\pm}7$ on average. In the case of fruits, the pears, apples, and melons has been considered worthy to take the firefly larva fed with the current land snails.

• Korean Journal of Poultry Science
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• v.41 no.1
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• pp.39-44
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• 2014

The goal of this study was to evaluate the growth performance of crossbred strains using Korean native chicken (KNC). The data were collected from 2012 through 2013 at Poultry Science Division, National Institute of Animal Science, Korea. The number of chicks analyzed in this study was 375. Crossbred were (A) $R{\times}S$, (B) $D{\times}H$, (C) $D{\times}S$, (D) $C{\times}Y$ and (E) $Y{\times}H$. The fertility rates of strains were 94.9% in crossbred A, 91.9% in crossbred B, 91.8% in crossbred C, 89.7% in crossbred D and 93.8% in crossbred E, respectively. The fertility was highest in crossbred A, but crossbred C showed the lowest (p<0.05) based on the hatchability. The crossbreds B and C exhibited a superior performance on body weight gains during growing stages but crossbred D showed the lowest (p<0.05). The feed intake was to the pattern of body weight. The feed intake of crossbred D was significantly lower than other crossbreds. Also, feed conversion ratio of crossbred D showed the lowest (p<0.05). Egg production ratio of crossbred D was significantly higher compared to the other crossbreds. These results suggest that the development of new crossbreds of commercial Korean Native Chickens should be required for better performance.

• The Korean Journal of Malacology
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• v.28 no.3
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• pp.215-223
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• 2012

The ecophysiological characteristics of the oyster Crassostrea gigas in Taean area, west coast of Korea, were investigated after main spawning season from September 2011 to January 2012 to confirm the recovery process of condition. The cupped oysters, from 4 different off-bottom culture areas were compared the gonad indices, histological analysis combined with measurement of RNA/DNA contents and ratios in gonad of each sex were undertaken. To evaluate the health condition of oyster after spawning, the RNA/DNA ratio in adductor muscle, fatness and condition index (CI) were used. The results showed that cupped oysters cultured in Uihang coastal area were different physiological aspects than other experiment areas, namely continuously decreasing RNA/DNA content and ratio in adductor muscle, lowest CI and fatness. Oysters cultured in Iwon Station 1 and 2 showed fast recovery in RNA/DNA, increase in fatness and CI during post-spawning stage until October rapidly and there after it decreased. Oysters in Shinduri showed rapidly decrease in fatness and CI until October. On the contrary to this factors, RNA/DNA ratio in adductor muscle increased as like protein until October. Partially spawning season could be observed until December in Shinduri and Iwon Station 1.

• Korean Journal of Ichthyology
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• v.29 no.4
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• pp.235-243
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• 2017

Reproductive characteristics of Rhodeus pseudosericeus (Pisces: Acheilognathinae) was investigated at the Heukcheon (River), Yangpyeong-gun, Gyeonggi-do, Korea from January to July in 2012. This fish prefers heavily vegetated stagnant pool with Phragmites japonica and Salix koreensis and area with high proportions of sand and mud. The standard length of the population indicated that 13~22 mm group is 0-year old, 30~45 mm group is 1-year old, 45~55 mm group is 2-year old and 45~70 mm group is more than 3-year old (June in 2012). The sex ratio of female to male was 1 : 0.80. The spawning season was from March to June with water temperatures in the range $11.0{\sim}26.2^{\circ}C$. The embryos were found with no egg mass in Unio douglasiae sinuolatus and the number of those was 1~22 ($5.8{\pm}5.51$). The number of the embryos found in each of the four parts of the mussel gill was 1~9 ($2.7{\pm}2.16$) in left outer, 1~2 ($1.5{\pm}0.71$) in left outer, 1~5 ($1.8{\pm}1.79$) in left outer and 1~22 ($5.8{\pm}5.51$) in left outer.

• Development and Reproduction
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• v.6 no.1
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• pp.37-44
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• 2002

First sexual maturity, sex ratio, spawning frequency, deposition of the egg capsules and fecundity of the female Rapana venosa(Valenciennes) inhabited in the artificially closed slag deposit area, Gwangyang Bay were investigated by histologicai and visual observations for natural living resource management. The rate of individuals reaching the first sexual maturity was 51.6％ in females measuring 7.1~8.0 cm in shell height, and 100％ in those > 10.1 cm. The total number of egg capsules per individual and the mean number of eggs in an egg capsule were 192~382 and 500, respectively. However, the number of eggs per individual and sizes of egg capsules under lower salinity and deficient food conditions in the closed slag deposit area were smaller than those under the optimum salinity and sufficient food conditions in the open regions. Fecundities of the species were approximately from 96,000 to 191,000 eggs/individual with two to low broods(spawning frequencies) during the spawning season. The duration of development in egg capsules was 18~19 days at about 18~2$0^{\circ}C$. R. venosa is a species whose embryos hatch as veliger larvae, not juvenile snail. The sex ratio of female : male was not significantly different from 1 : 1($\chi$$^2$= 0.23, p>0.05).