• Korean journal of applied entomology
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• v.40 no.1
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• pp.59-67
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• 2001

The potential of two entomopathogenic nematodes, Sreinernema carpocapsae Pocheon strain and Heterorhabditis bacteriophora Hamyang strain as biological control agents was evaluated against mushroom ny, Lycoriella mali in laboratory and field. Mortality of L. mali was significantly different according to nematode species, concentration, temperature, and developmental stage of fly S. carpocapsae was more effective than H. bacteriophora. Mortality of L. mali was higher at $25^{\circ}C$ than at $20^{\circ}C$. In addition, the 3rd instal and the 4th instar of L. mali were more susceptible than the 2nd instar. The lowest $LC^{50}$ value was represented by S. carpocapsae, 20.0 infective juveniles (Ijs) in the 3rd instar, 27.5 Ijs in the 4th instar at $25^{\circ}C$. S. carpocapsae infected all the developmental stages of L. mali except egg stage and the 1st instar of larva. The highest mortality was shown in adult female representing 74.0% at$20^{\circ}C$ and 80.0% at $25^{\circ}C$.L. mali female adult was influenced by S. carpocapsae in oviposition. The number of eggs by L. mali female infected by nematodes was much lower than uninfected females. S. carpocapsae was dispersed by infected L. mali adult with higher numbers by females than males. When S. carpocapsae was applied at the rate of $2.25{\times}10^{5}\;and\;4.5{\times}10^{5}\;Ijs/1.5\;\textrm{m}^2$ in the mushroom house, mortalities were 42.2% and 81.6%, respectively. The infective juveniles of nematodes survived for 14 days in the mushroom medium. However, nematodes did not affect mushroom growth.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.277-286
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• 2006

Population ecology of Cobitis tetralineata was examined at Churyeong Stream, Seomjin River, Korea. C. tetralineata inhabited on the sand bottoms with $10{\sim}20cm/see$ in current velocity, and $30{\sim}150cm$ in water depth. This species was active on the sand during the daylight hours from March to October, but they hibernated in the inside of the sand during the winter season. Sex ratio of female to male was 1:0.57, and female was $20{\sim}30mm$ (TL) larger than male. The age group of C. tetralineata (female) population showed that the $20{\sim}40mm$ group is 0+ years old, the $45{\sim}65mm$ group 1+ years old, the $65{\sim}90mm$ group 2+ years old, and the group longer than 90 mm over 3 years old. Males $13{\sim}14$ months old after hatching had lamina circularis at the base of its pectoral fin as a secondary sexual character. And in its spawning season, lateral color pattern of male was changed as a sexual dimorphism. The spawning season may be from late June to middle July, $22{\sim}26^{\circ}C$ water temperature. The average number of mature eggs in ovary was about $1,288{\pm}583(474{\sim}2,976)$, egg diameter was about $0.98{\pm}0.1mm$. C. tetralineata fed mainly on Chironomidae, Arcellidae, Branchioda and Algae. The feeding rate was the highest in April and September, but they did not fed in the winter.

• Korean journal of applied entomology
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• v.34 no.4
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• pp.300-307
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• 1995

This study was carried out to investigate the life cycle of Cephonodes hylas (Linne), that is damaging to Gardenia jasminoides Ellis in the seedbed at Namhae during 1984 and 1985. Results are summarized as follows. The eggs were laid in mass on the leaf surface of the host plants. The oviposition period lasts for 26 days after late-May. The average number of eggs and average hatching rate were 20.36 and 97.61% , respectively. It takes 14-16 days until hatching. The egg shape was oval which its size was 1.01 mm in diameter and 1.48 mm in length. The body length of each larval instar from the 1st to the 5th were $3.52\pm$1.01, $6.46\pm$0.45, $13.19\pm$4.27, $24.08\pm$2.22 and $43.71\pm$5.62 mm, respectively. The average weight of each larval instar were $13.34\pm$2.41, $29.83\pm$6.88, $76.64\pm$31.31, $292.09\pm$107.70 and 2,$144.84\pm$760.70 mm, respectively. The larval period was observed from July to October, and total duration of larval stage was 116 days in which duration of each larval instar from the 1st to the 5th were 12, 36, 32, 16 and 20 days, respectively. During larval stage, a larvae feed on 17~18 seedlings. The 5th instar larvae built its place in soil for overwinter and became pupa. The body length of pupa was 33.6 mm and average weight was 2,032 mg Adult was emerged from overwintened pupa from mid through late-May in the followings year. The sex ratio of female was 42.82% and the color ratio of brown was 89.93%.

• Korean Journal of Poultry Science
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• v.17 no.4
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• pp.255-268
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• 1990

This study was carried out to investigate the time-trends of genetic parameters of the dosed flock population which selected for improving egg production. Data for two layer pure lines, Line-W (Single Comb White Leghorn) and Line-B (brown layer) which have been maintained at the Mani Breeding Farm were collected from 1980 to 1985 during 5 generations. The effective number of parents per generation ranged from 148 to 366 in Line-W and 85 to 355 in Line-B, and the cumulative expected inbreeding coefficients during 5 generations of selection were 15％ and 1.6％. So inbreeding could not be considered a critical factor on estimating the genetic parameters, heritabilities and genetic correlations Heritabilities of EN 300 and EN 400, primary two selected traits were significantly decreased during 5 generations but the estimates of the other 03its not showed the consistent decreasing pattern significantly. No time trends of probable consequence were evident in the genetic correlation coefficients of the traits studied. The reason for that situation was attributed to the fact that selection was conducted for multiple objectives and the relative importance of selection for the studied traits were not consistent by generations.

• Korean journal of applied entomology
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• v.19 no.2 s.43
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• pp.85-89
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• 1980

This experiment was carried out to investigate the life history of the Three spotted plusia (Chrysodeixis agnata Staudinger) in the laboratory in 1976. (1) Female deposited $1202{\pm}150.6$ eggs during the oviposition period which was $13.3{\pm}1.2$ days. (2) Especially, larvae were distinguished with 5-instar type and 6-instar type. The egg period was 2 days and adult longevity was $21.29{\pm}3.15$ days for female and $19.14{\pm}2.47$ days for male. Larval period and pupal period were $15.36{\pm}1.59,\;7.82{\pm}1.01$ days for the 5-instar type and $16.92{\pm}1.08,\;8.23{\pm}1.09$ days for the 6-instar type. (3) Width of head capsule of the 5-instar type was $2.77\~2189mm$ and this of the 6-instar type was $2.78\~22.38mm$. (4) A highly significant correlation was recognized between the log-width of head capsule and the number of instar.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.4
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• pp.272-279
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• 2019

The study was conducted to evaluate the seminal attributes and cryobanking of Achhami (Bos indicus) bull semen. Of two Achhami bulls, 8 ejaculates from each bull were evaluated for seminal attributes. For semen freezing and cryo-banking, 4 ejaculates (having ≥2 mL semen volume, ≥75% of sperm motility and ≥1,000 × 10⁶ cells/mL of sperm concentration) from each bull were used. Semen samples were diluted in egg-yolk-tris-citrate extender using a two-step dilution protocol, and were frozen in liquid nitrogen (LN₂) vapour in a styrofoam box. The mean semen volume, colour, sperm mass activity, motility, viability, concentration, abnormal acrosome, midpiece and tail and, abnormal head of two Achhami bulls were 4.4 ± 0.5 mL vs. 2.5 ± 0.2 mL, 2.5 ± 0.1 vs. 2.4 ± 0.1, 3.5 ± 0.1 vs. 3.5 ± 0.1, 77.0 ± 1.1% vs. 78.3 ± 1.3%, 94.4 ± 0.5% vs. 91.0 ± 0.6%, 1137.7 ± 73.7 × 10⁶ cells/mL vs. 1060.0 ± 44.3 × 10⁶ cells/mL, 10.2 ± 0.5% vs. 10.3 ± 0.5% and 6.7 ± 0.5% vs. 8.2 ± 0.3%, respectively. The post-thawed sperm motility and viability were 53.0 ± 2.0% vs. 50.0 ± 0.0% and 80.2 ± 0.4% vs. 73.2 ± 0.7%, while evaluating by computer-assisted sperm analysis (CASA) system, the percentage of the progressive motility, fast motility, slow motility, local motility and immotile sperm were 75%, 68%, 7.4%, 16.6% and 8.6%, respectively. A total number of 620 doses semen straw were cryo-banked. Due to the acceptable post-thawed sperm motility and viability recorded, cryopreservation of Achhami semen is hereby recommended so as to preserve the Achhami breed. For further validation, the fertility will be observed from the produced frozen semen.

• Korean journal of applied entomology
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• v.38 no.2
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• pp.85-91
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• 1999

Torymus sinensis was found to be a solitary ectoparasitoid attacking the larvae ofDryocosmus kuriphilus. The sex ratio of Torymus sinensis was close to 1 : 1 in foreign chestnut varieties.Under constant temperatures of 15"C, 20$^{\circ}$C, and 25"C, the preoviposition period and longevity of theadult was longer at lower temperatures when fed on honey. Most of the Torymus sinensis female havemature eggs in their ovaries just after emergence. The number of mature eggs reached to average 22.5individuals per female in four days, which was the highest value, after the emergence and then decreasedgradually. Eggs were laid on the larvae of the host or attached on inner surface of the gall chamber. Theeggs were oval in shape, measuring 0.49 mm length and 0.13 mm width and the color of the justoviposited egg was milky white. The larvae appeared in one day after being deposited at 20$^{\circ}$C. Thepupae, 2.25 mm length for female and 1.89 mm length for male, was milky white in color just afterpupation but became black later. In Kangwon Province, development period of chestnut galls formated byDryocosmus kuriphilus were mid April to late May and its primary parasitoid, Torymus sinensis adult,emerged from withered previous year galls in early April to early May. This species has one generation ina year, and hibernated with the matured larvae. hibernated with the matured larvae.

• Korean journal of applied entomology
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• v.21 no.2 s.51
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• pp.78-86
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• 1982

The ecological studies were conducted to identify some bark-beetles on apricot and plum trees in Jeonnam province. Harmful bark-beetles caught from apricot and plum trees were identified as Scolytus seulensis. Xyleborus atratus., X. germanus, X. rubricollis and X. saxeseni. The seoul barkbeetle emerged during the period from early May to late October $1980\~1981$, it happens twice in a year, with the peak July 10 and August 25 in 1950, July 15 and August 20 in 1981. A daily peak emerged for adults was at 11 AM to 1 PM. Distribution of holes on the apricot stems varied; more than 100 holes per meter in Henderson (Apricot) and Y-49057 (Apricot), 12 holes per meter in Derbyroyal (Apricot). Comparatively more holes were found in the European variety, and the cardinal distribution was in the order of east, south, west and north. The longer the longth of the mother-gallery, the greater number of egg-gallery found. Optimum temperature for mating was $27^{\circ}C$. The time for mating was longer during May-June than July-August. The fruit weight of damaged plum tree reached 12.25g around four weeks after flowering; where as that of normal tree increased up to 63.5g at harvest time. The natural enemy of the seoul bark beetle was Eurytoma sp. They were found as mature larva or pupa and they emerged from early May to the middle of June. Adult longevity was about a week.

• Korean journal of applied entomology
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• v.25 no.4 s.69
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• pp.201-207
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• 1986

This study was conducted to investigate the host plants in greenhouse, developmental periods at different temperatures and distribution patterns on cucumber of the greenhouse whitefly, Trialeurodes vaporariorum(TV) in $1984{\sim}1985$. Host plants of 39 species belonging 27 families only in the greenhouse were recorded in 1984. Longevity of adult was 26.8 days and number of eggs per female was 305 eggs at $25^{\circ}C$. The eggs, larval and pupal periods were 8.2, 8.3, 7.5 days respectively at $25^{\circ}C$. The threshold temperature of development from egg to larva was $8.8^{\circ}C$. Survival rates from eggs to adults at $22^{\circ}C,\;25^{\circ}C,\;30^{\circ}C$ were 70.3%, 58.0% and 66.4%, respectively. Adults and eggs were found only on the apical leaves of cucumber plants within 40 days after transplanting. On the other hand, larva distributed on the middle leaves and pupa on the lower leaves.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.458-464
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• 1993

From November 1992 to January 1993, the rockfish, Sebastes inermis was reared in the laboratory, and observed the developmental stage of the eggs and larvae squeezed from the parent fish. On December 4 1992, developing eggs at morula stage were obtained from female parent fishes($17.4{\sim}20.3mm$ in total lenght(TL)). The diameter of eggs ranged from 1.20 to 1.35mm(n=50), and oil globules in white color were found in the eggs. Hatching began about 55 hours after morula stage at the water temperature of $9.2{\sim}12.3^{\circ}C$. The newly hatched larvae measured from 2.90 to 3.35mm in TL with $8+12{\sim}13=20{\sim}21$ myomeres. Total lengths of the larvae will be from 5.75 to 6.15mm in 27 and 30 days after the hatching, respectively. Myomere number was $8+17{\sim}18=26$.