• Journal of Aquaculture
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• v.11 no.2
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• pp.141-149
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• 1998

Spawning inducement of striped knife-jaw, Oplegnathus fasciathus, was attempted by two experiments. In experiment I (Exp. I), water temperature was gradually increased from 14.5$^{\circ}C$ in December 15, 1996 to $21.0^{\circ}C.$ in February 22, `997 and then maintained at this level. Photo-period was also gradually increased from 10.5L/13.5D in December 15, 1996 to 15.5L/8.5D in February 17, 1997, and then maintained at this level. In experiment II (Exp. II), water temperature was increased in the same way from Exp. I. Photoperiod was natural conditions from December 1996 to March 9, 1997, and then suddenly increased to 15.5L/8.5D until the end of experimental period. Spawning of the fish was occurred from February 22 through April 2, 1997 (for 40 days) in Exp. I. Number of total spawned eggs was 30.04 million and fertilization rate was 77.2%. The fish began to spawn at $21.0^{\circ}C.$ and 15.5L/8.5D. It requied 65 days to spawn since the water temperature had increased from $14.5^{\circ}C.$ to $21.0^{\circ}C.$. Spawning of the fish was not occurred until March 9, 1997 in Exp. II. After 7 days, photo-period was suddenly incresed to 15.5L/8.5D and fish were spawned from March 17 through April 4, 1997 (for 20 days). Number of total spawned eggs was 21.28 million and fertilization rate was 72.1%. The fish began to spawn at $21.0^{\circ}C$ and 15.5L/8.5D. It required 65 days to spawning since the water temperature had increased from $14.5^{\circ}C$ to $21.0^{\circ}C$.

• Korean Journal of Poultry Science
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• v.33 no.1
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• pp.41-47
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• 2006

A study was conducted to investigate the effect of supplementing earthworm meal(EWM) on the egg quality and performance of laying hens. A total of 360 laying hens at 55 weeks of age were fed the experimental diets containing 0(Control), 0.3 and 0.6% of EWM for 5 weeks. Eggs were collected and weighed in every day and egg production and feed conversion were weekly recorded. However egg quality were measured fer last week of experimental period. When fed both 0.3 and 0.6% of EWM, egg production and daily egg mass tended to increase but were not different between those treatments. Feed intake and feed conversion ratio of laying hens were not different among three groups. Egg shell thickness, breaking strength, color and egg yolk color were tend to improve in both 0.3 and 0.6% of EWM compared to those of control. The haugh units(HUs) showed no difference among each treatments at 14 after laying egg, but increased in EWM treatments compared to control for storage period. As, Cd, Cr, Hg and Pb detected 4.41, 1.23, 1.18, 0.00 and 3.39ppm in EWM, respectively, but which were not detected in control. It assumed that supplementing 0.3% of earthworm meal in the 55 weeks old laying hens diet, improved the laying performance and egg quality.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.61-64
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• 1985

This study was carried out to investigate the seasonal occurrence and developmental periods of Rice stem maggot (RSM), Chlorops oryzae Matsumura, at laboratory and in the fields in $1980{\sim}1982$. RSM occurred three generations a year. Peak of the first, second, and third generation was middle to late May, early July and middle September. Longevity of the first generation adult averaged 18.9 days and the oviposition was 50 eggs per fly. The eggs, larval and pupal period was 7, 25, 14 days respectively.

• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.367-373
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• 2009

This experiment was conducted to determine optimum dietary levels of dietary energy and protein for laying performance and egg quality in organic laying hens. In a $2{\times}3$ factorial arrangement, 360 Hy-Line pullets (21 wk of age) were randomly assigned to experimental diets with 2,800, 3,080, and 3,360 kcal of ME/kg of diet, each containing 16 and 18% CP, respectively. Each dietary treatment was replicated 4 times, and feed and water were provided ad libitum. Experimental birds were raised in floor and received 14h of light throughout 52 weeks of experimental period. The birds were observed for feed consumption, egg production, egg weight, egg mass, feed conversion ratio, Haugh unit, shell thickness, and shell color at 30, 50, and 70 wk of age. Egg production, egg weight, and egg mass were higher (P<0.05) in hens receiving diets with 2,800 kcal/kg of ME/kg of feed than those fed diets containing 3,080 and 3,360 kcal of ME/kg of diets. Eggshell breaking strengths were not significantly different among the dietary ME and CP concentrations. Eggshell thickness was higher (P<0.05) in hens receiving diets with 3,360 kcal of ME/kg of feed than those fed diets containing 2,800 and 3,080 kcal of ME/kg of diets at 50 and 70 week. With increasing in dietary energy levels, the concentrations of blood total cholesterol were also significantly increased. Overall, the laying hens fed organic diet of 2,800 kcal ME/kg and 16% CP showed superior egg production than those of other dietary regimens.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.381-387
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• 2019

From 2017 to 2019, the ovipositional and the developmental characteristics of Gampsocleis ussuriensis Adelung in the Buan area of Jeonbuk Province were examined. G. ussuriensis were mostly found in the weeded areas around the reservoir, where the adults first appeared in mid-July, showed up where by the early September, and overwintered in eggs. Nymphs appeared in early April to mid-July the next year. The nymphs hatched from early April and adults appeared after molting five times. The ovipositional period of G. ussuriensis was approximately 58 days. The total number of eggs per female was 124. The mean longevity of adults was 95.6 days for females and 84.8 days for males. Ovipositional mats were best with mixed Masato and Coco-Pitt at a ratio of 7:3. Developmental period of G. ussuriensis nymphs was 64.1 days at 24℃ and was longer than at different temperatures. The higher the temperature, the shorter the developmental period. The survival rate of nymphs was the best at 32℃ in 77.8%. The higher the density while rearing, the lower the survival rate, and the faster the development and molting velocity.

• Korean journal of applied entomology
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• v.39 no.4
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• pp.245-250
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• 2000

These studies were conducted to investigate the effect of temperature on the development and seasonal occurrence of Chrysopa pallens Ramber, a predator of aphids. Mean developmental periods of C. pallens from egg to adult emergence at four different temperatures of 17, 22, 27, and $30^{\circ}C$ were 39.5, 32.0,25.0, and 19.8 days, respectively. The longevities of adult females of C. pallens at the four temperatures were 84.7, 79.6, 77.7, and 69.8 days, respectively, whereas the total numbers of eggs laid by a female were 973, 1085, 1637, and 1735, respectively. Egg hatchability, rate of adult emergence, and sex ratio of C. pallets were slighty higher with increased temperature with 84.1~95.9%, 67.6~86.3%, and 1:1. Under three humidity conditions of 35, 55 and 75% RH, the mean developmental periods of C. pallets from egg to adult emergence at the $27^{\circ}C$ were 26, 24, and 22.9 days, respectively, while the number of eggs laid by a female were 1042.8, 1526.5, and 1640.0, respectively. Oviposition of C. pallets usually began 5~6 days after the emergence at $27^{\circ}C$. Then females laid ca. 30~40 eggs a day, reaching a peak of 80~90 eggs a day about 22~28 days after the emergence. Population fluctuation of M. persicae and A. gossypii showed the highest peak in late May through the mid-June, and the second peak appeared in early~mid-September. The adult occurrence of C. pallens by the light trap record started from mid-May, and show two peaks, in mid-late July and mid-late September in Chonbuk area.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.461-467
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• 2012

Developmental characteristics of Geocoris pallidipennis were investigated at a constant temperature ($20{\pm}1$, $25{\pm}1$, $30{\pm}1$, $35{\pm}1$, $37.5{\pm}1$ and $40{\pm}1^{\circ}C$), under long day illumination 16:8 (L:D) and constant relative humidity ($80{\pm}10%$). From egg to adulthood, the lower developmental threshold and the effective accumulative temperature were $14.8^{\circ}C$ and 399.1 day-degree, respectively. The experimental results at $35^{\circ}C$ were as follows. The egg period was 5.6 days (hatchability: 81.1%) and the nymphal period was 14.3 days (1st: 3.2, 2nd: 2.2, 3rd: 2.7, 4th: 2.7, 5th: 3.6). Female longevity was 33.8 days and the oviposition period was 29.2 days. Total egg production was 111.2 eggs and the maximum daily egg production was 14.8 eggs (in 7th days). However, although some eggs and nymphs developed at $37.5^{\circ}C$, G. pallidipennis could not develop at $40^{\circ}C$, The total egg production at $40^{\circ}C$ was only 22.1 eggs. When G. pallidipennis was fed on Bemisia tabaci pupae, daily prey consumption by nymphs (1st, 3rd and 5th) and adults was 1.9, 7.3, 18.7 and 29.5, respectively.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.43-51
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• 2003

This study was carried out to develop the forecasting model of Pseudococcus comtocki Kuwana for timing spray. Field phonology and temperature-dependent development of p. comstocki were studied, and its stage transition models were developed. p comstocki occurred three generations a year in Suwon. The 1 st adults occurred during mid to late June, and the 2nd adults were abundant during mid to late August. The 3rd adults were observed after late October. The development times of each instar of p. comstocki decreased with increasing temperature up to 25$^{\circ}C$, and thereafter the development times increased. The estimated low-threshold temperatures were 14.5, 8.4, 10.2, 11.8, and 10.1$^{\circ}C$ for eggs, 1st+2nd nymphs, 3rd nymphs, preoviposition, and 1st nymphs to preoviposition, respectively. The degree-days (thermal constants) for completion of each instar development were 105 DD for egg,315 DD for 1st+2nd nymph, 143 DD for 3rd nymph, 143 DD for preoviposition, and 599 DD for 1 st nymph to preoviposition. The stage transition models of p. comstocki, which simulate the proportion of individuals shifted from a stage to the next stage, were constructed using the modified Sharpe and DeMichele model and the Weibull function. In field validation, degree-day models using mean-minus-base, sine wave, and rectangle method showed 2-3d, 1-7d, and 0-6 d deviation with actual data in predicting the peak oviposition time of the 1st and 2nd generation adults, respectively. The rate summation model, in which daily development rates estimated by biophysical model of Sharpe and DeMichele were accumulated, showed 1-2 d deviation with actual data at the same phonology predictions.

• Korean Journal of Poultry Science
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• v.18 no.2
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• pp.67-84
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• 1991

The purpose of this study was to investigate the effects of dietary protein levels on laying hen performance. The level of methionine and lysine were 0.32% and 0.64%, respectively and the levels of protein were 12%, 13%, 14% or 15%. Total 384 laying pullets of 22weeks age were reared from January 28, 1989 to March 23, 1990 for 60 weeks. The results obtained were summarized as follows : 1 Egg productions was highest at 15% of protein in phase I, 14% in phase II, and 13% in phase III, and there was significantly different egg Production among treatments during phase I and phase II (P＜0.05). 2. Egg weight was heaviest in 14% of protein treatment in three phases and they showed significantly different egg weight among different levels of protein in phase I (P＜0.01), phase II and III (P＜0.05) , but there was not significantly different between 14% and 15% of protein. 3. Daily egg mass tends to increase followed by increasing of protein level and showed signifiant differences among treatments in phase I and phase II (P＜0.01). 4. The 14% of protein treatment showed the highest daily feed intake and it showed significant difference in phase I and phase II (P＜0.01) , but there was no significant difference between 14% and 15% of protein. 5. Feed efficiency was improved significantly followed by increasing of protein level in phase I (P＜0.01) and phase II (P＜0.05), but there was no significant difference among treatments in phase III. 6. Viability tends to increase as increasing of protein level, but there was no significant difference among treatments. 7. Utilizabilities of dry matter, crude protein and ether extract of experimental diets were not different among treatments, but the utilizability of carbohydrate tends to increase as increasing of protein level (P＜0.05). 8. Eviscerated yield and abdominal fat accumulation was not difference among treatments. 9. Egg shell quality and chemical composition of egg content were not different among treatments. 10. The feed cost per kg egg mass showed the cheapest in 13% of protein treatment in all phase, but there were no significant differences among treatments.

• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.43-49
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• 2007

Experiments have been performed to investigate biological characteristics of Diglyphus isaea (Walker), an ectoparasite of Liriomyza trifolii (Burgess). At $25^{\circ}C$, development time of D. isaea was estimated as 1.3 days for eggs, 4.5 days for larvae and 6.3 days for pupae. Adult longevity was 25.1 days, and a female adult could lay 305.3 eggs throughout its lifetime. Number of L. trifolii parasitized or killed by the wasp was 962.2 individuals/adult. Most of all parasitized or killed larvae were identified as third instar. With 20% honeyed water as food source, half of the adults could survive 180 days at $5^{\circ}C$, 150 days at $10^{\circ}C$, and 90 days at $15^{\circ}C$. After storing at $10^{\circ}C$ with absolute honey for 30 days, 70 days and 140 days, a female adult in room temperature laid eggs 190.8 individuals, 104.0 individuals and 89.4 individuals, respectively.