• Korean journal of applied entomology
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• v.32 no.2
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• pp.193-199
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• 1993

The morphological relationship between Drosophila melanogaster and D. simulans, and their hybrids were investigated using comparisons of internal reproductive organs. male sex comb tooth number and male genital discs. InterspecIfic hybrids of all crosses were completely sterile, and had rudImentary gonads. Dysgenic ovaries and testes were morphologically similar to those of gonadal dysgenesis stenlity associated with the PM system in D. melal1ogaster. The mean number of sex comb tooth in D. melrmogaster, D. simulans and their male hybrids were 10.73, 8.35 and 9.97, respectively. The general aspects of the genital disc of the malo hybrid were a mosaic-like structure between D. melanogaster and D. simulans.

• The Korean Journal of Ecology
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• v.22 no.5
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• pp.271-276
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• 1999

Luminescent patterns of the firefly Hotaria papariensis were classified into routine flashing and courtship flashing, and they were analyzed into duration and period. Flash period of male was changed from 1.26 sec (routine flashing) to 1.12 sec (courtship flashing) and the female's was changed from 2.99 sec to 1.06 sec in this species. Duration time of male increased approximately 1.4-fold from 0.12 sec (routine flashing) to 0.17 sec (courtship flashing) and period of male decreased 0.88-fold from 1.26 sec (routine flashing) to 1.12 sec (courtship flashing). Duration of female increased about 1.5-fold from 0.15. sec (routine flashing) to 0.19 sec (courtship flashing) and period of female decreased almost 0.35 from 2.99 sec (routine flashing) to 1.06 sec (courtship flashing). Hertz frequencies of them were 0.8 (routine flashing of male), 0.9 (courtship flashing of male), 0.3 (routine flashing of female) and 0.9 (courtship flashing of female), respectively. The spectral emission of H. papariensis was detected at 400 nm to 700 nm, and the highest peak wave length of this species was approximately 600 nm, but some 500 to 600 nm wave lengths were present.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.1-14
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• 2022

Moths have a well-developed sex pheromone communication system. Male moths exhibit an extremely sensitive and selective sex pheromone detection system so that they can detect the sex pheromone produced by conspecific females and locate them for successful mating. Using the pheromone detection system, male moths display characteristic stereotypic behavioral responses, flying upwind to follow intermittent filamentous pheromone strands in pheromone plume. The chemical composition of female sex pheromone in moths, typically comprised of multiple compounds, is species-specific. Male moths contain specialized pheromone receptor neurons on the antennae to detect conspecific sex pheromone accurately, and distinguish it from the pheromones produced by other species. The signals from pheromone receptor neurons are integrated and induce relevant behavior from the male moths. Male moths also contain olfactory sensory neurons in pheromone sensilla, specialized for pheromone-related behavioral antagonist compounds, which can enhance discrimination between conspecific and heterospecific pheromones. Here we review reports on the sex pheromone detection system in male moths and their related responses, and suggest future research direction.

• Korean Journal of Poultry Science
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• v.19 no.4
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• pp.205-215
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• 1992

This study investigated the characteristics of Korean Native Fowl (KW) to standarize the feeding regime and compared with those of broiler. The characteristics of KNF studied were meat productivities and carcass traits. The data were collected for 14 weeks from March to June, 1992, by recording from 200 birds(50 birds per each sex and 2 breed) were as follows ： 1. Average body weight at 14 weeks of age of Korean Native Fowl(KW) and broiler were 868.7g and 3,526.6g, respectively and were 26.6 times and 72.9 times of day old chicks weight averages, respectively. 2. The carcass yields during 9∼14 wks were 74.1∼78.5％ for KNF male, 73.g∼77.5％ for KW female, 72.2∼76.9％ for broiler male and 71.7∼76.4％ for female. It was shown that carcass yields of KNF was 2％ higher than that of broiler. 3. In edible portion, the yields of wings weight to carcass weight were 11.5∼12.4％ for KNF male, 11.5∼13.1％ for KNF female, 10.7∼11.9％ for broiler male and 10.7∼12.2％ for broiler female, it was shown that wings weight of KW was higher than that of broiler and wings weight of KNF during 9∼14 wks. 4. The portions of back and breast weight were higher than those of KNF during 9∼14 wks. The back portions in carcass weight were 15.4∼17.0％ for KW male 15.4∼16.8％ for KNF female, 17.2∼19.0％ for broiler male, and 17.2∼19.0％ for broiler female. The breast portions in carcass weight were 19.6∼22.0％ for KNF male, 20.2∼22.7％ for KNF female 23.S∼24.5％ for broiler male, and 25.1∼27.7％ for broiler female. 5. The portion of thigh and drumsticks weight in carcass weight of KNF was similar to that of broiler. They were 26.8∼28.0％ for KNF male, 25.5∼27.1％ for KNF female, 27.7％ for broiler male, and 26.9％ for broiler female, respectively. 6. For the weight of inedible portion during 9∼14 wks, feather weight of KNF was 5.3∼6.8％ of live weight and 3.8 ∼4.4％ in those of broiler. This result indicated that KNF has more rooms for improvement than broiler. 7. Abdominal fat weight was 2.42∼3.88g for KNF male and 1.84∼3.08g for KNF female, which was 0.5％ of carcass weight. But broiler has more abdominal fat than KNF as 39.4∼56.3 g for male, 33.3∼67.8 g for female which was 2.5 ∼3.0％ of carcass weight.

• Korean journal of applied entomology
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• v.51 no.3
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• pp.207-213
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• 2012

The cryptic mealybug, Pseudococcus cryptus, has been increasingly damaging citrus, particularly those plants grown in plastic greenhouses. This study was conducted to monitor the seasonal phenology of adult male cryptic mealybugs and to determine the timing for control using a sex pheromone trap. Adult males responded to a synthetic sex pheromone and trap color. An increasing number of males were attracted to the traps with increasing concentrations of sex pheromone up to 5 mg. The males occurred annually four times and had three cohorts at a time due to different overwintering developmental stages. After overwintering the adult males began to in mid-late April. A positive correlation was observed between the number of adult males caught in traps and the mean density per twig of all motile stages except first stage nymphs of the cryptic mealybugs. The peak time for the first nymph to occur was estimated from the maximum attraction time of the males, and the cumulative degree days (DD) was 350 DD, similar with the preoviposition period.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.500-507
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• 1998

Using a sledge net, the benthic amphipods were taken over one cycle of the neap and spring tides in January 1993 at the sandy shore surf zone of Dolsando, southern Korea. From these samples, we investigated the diel and tidal effects on the intraspecific zonation of Pontogeneia rostrata. The density of p. rostrata was higher during neap tide than spring. Of three categories (adult males and females and juveniles), juveniles and males attained to its highest density during neap and spring tides, respectively. Length- frequency data show that the high mortality of juveniles seemed to occur in winter. In the surface at night, it is significant that juveniles were significantly more abundant during neap tide than spring, whereas both adult males and females were more abundant during spring tide than neap. This suggests that the vortical migration patterns of juveniles and adults vary with the type of tides. During flood of spring tide, more than $90\%$ of population collected at the area above the mean sea level (MSL) were adults. With a decrease of female/male ratio, size of males increased there but that of female did not change, indicating an active migration of large males. This behavior can provide an extension of distribution area far large males, and also give a competitive advantage to large male against small one for mate and feeding. Although adult p. rostrata was collected at 100 cm above MSL at night during spring tide, a major portion of population as usually present on the shore below MSL. The center of zonation was restricted from 50 cm to 250 cm below MSL.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 1998.07a
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• pp.39-40
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• 1998

수온과 광주기를 조절한 실험구는 대조구에 비해 GSI의 peak가 2개월 늦어졌으며, 난소의 발달도 지연되었다. 암컷 혈중의 $E_{2}$와 T 농도도 성숙 단계의 지연에 따라 peak가 각기 다르게 나타났다. 그러나 수온과 광주기를 조절한 그룹의 일부개체는 성숙이 지연되지 않았으며, 수컷의 GSI나 수컷 혈중의 T 농도도 수온과 광주기의 변화에 영향을 받지 않았다.

• Korean Journal of Ichthyology
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• v.24 no.3
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• pp.220-226
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• 2012

The aim of this study is to observe the reproductive behavior of the marine medaka, Oryzias dancena, and determine the factors of reproductive behavior to provide useful information for improving their artificial reproduction techniques. The reproductive behavior of the marine medaka was observed in laboratory aquaria. Once the experiment began, all of the males chased the females. The males attempted to stimulate the urogenital openings of the females. While chasing a female, a large male would bite a relatively small male's anus. Larger males expelled smaller males with biting, and the defeated males were barred from the female. After the other males were expelled, the remaining male approached and drew alongside the female. The male's dorsal and anal fins covered the female's body. Spawning began after complete covering took place. Spawning of males and females occurred simultaneously. The loadings for 2 factors were calculated. The calculation was restricted to 2 factors because these 2 factors explained about 81% of the total common variance (P<0.05) and the following factors possessed no practical significance. Two movements (biting, expelling) had high positive values for factor one. This factor related a male's defensive behavior to courtship behavior and spawning, and explained 23.1% of the total common variance (P<0.05). The second factor had high positive values for chasing, rejection, covering, and parallel swimming. This factor related a male's courtship behavior and female's defensive behavior to spawning, and explained 59.7% of the total common variance (P<0.05). This research provided basic biological data for the conservation of this species and useful information for improving their artificial reproduction techniques.

• Journal of Life Science
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• v.9 no.2
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• pp.182-193
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• 1999

In order to establish basic data of SAMP6 as an animal model for osteoporosis, present study has been designed to concentrate on the various biological aspects of SAMP6 such as growth index, hematology, blood biochemistry, biochemical characteristics, and bone and cortical thickness. Investigation period was for 15 months (3 months to 18 months of age) and biological characteristics have been examined throughout the study period. The results were summarized as follows : Decreased body weight of male SAMP6 was noticed from 7 months of age compared to from 18 months of age in female. Although there were no significant differences in organ weights, generally those of male mice were greater than those of females, especially in liver, kidney and lung. According to the analysis of blood biochemistry and hematology, the number of leukocytes in male mice was greater than that of female mice. There was a decrease in bone thickness in both male and female mice starting around from 7 months of age. Peak cortical thickness index was noticed at 5 months of age in both sexes. In femur, the highest $Ca^{2+}$ content for both sexes was noticed at 5 months of age, whereas the highest P$^{3+}$ content was noted at the age of 5 and 7 months in male and female mice, respectively. The contents of both elements were gradually decreased with age after peaks for both sexes. In summary, SAMP6 mice in KRICT colony show osteoporotic characteristics starting from 5 to 7 months of age, suggesting that at least 5 months of old animals should be used for studying the mechanism of osteoporosis or screening anti-osteoporosis drugs. This study also suggests that the cortical index thickness, $Ca^{2+}$ and P$^{3+}$ contents, and alkaline phosphatase activities can be used as indexes for drug screening.

• Korean journal of applied entomology
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• v.57 no.2
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• pp.105-115
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• 2018

The comstock mealybug is one of the serious insect pest in pear. It is necessary effective control methods such as attractive sex pheromone. Using sex pheromones is necessary for studying the physiology and ecology of insect pests. In the present study, the sex pheromone of comstock mealybug was used for investigating the flying acts of the adult male. As temperature increased, the development period of eggs shortened, but it was longer at $30^{\circ}C$. The mean number of eggs laid was 482 at $25^{\circ}C$ and males constituted 37% of the experimental population at $30^{\circ}C$. The flight of the male comstock mealybug was mostly restricted to a 2-4 hour period after sunrise, even if condition of light period is changed. Male mealybugs were incapable of upwind flight towards an attractant when air velocity was 1.5 mph. Preference of height was tested in a pear orchard. The ineffective heights of the traps were 2 and 2.5 m, whereas the effective heights were 1 and 1.5 m. Many captured males at 0.5, 1, and 5 m, and the number of captured males were similar in 10, 15, and 20 m. Male mealybugs were captured up to a distance of 50 m, suggesting that it is possible to control the male mealybugs that are more than 50 m away when sex pheromone traps are used.