• Korean journal of applied entomology
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• v.59 no.3
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• pp.185-202
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• 2020

The diapause induction season in Ostrinia furnacalis (Lepidoptera: Crambidae) was estimated in Suwon. Three batches of adult generations were observed, the first one from early May to early July, the second from early or mid-July to early or mid-August, and the third from mid-August to October. In outdoor larval rearing, colony rearing occurring from mid-July to mid-August produced both non-overwintering and overwintering larvae, whereas late-reared colonies produced only overwintering larvae. Larvae collected during July and August in maize fields produced both non-overwintering and overwintering larvae, whereas late-collected larvae produced only overwintering larvae. The results indicated that O. furnacalis has a bi- or trivoltine complex life cycle in this area. In the laboratory, when larvae of all instars within 9 h after molting were first treated to a diapause induction condition (11:13 h = light:dark photoperiod and 20℃), almost all larvae were induced to diapause. However, when similar treatments were conducted age-specifically for the 5th instar larvae, diapause induction rates in 3- and 4-day-old larvae of the 5th instar decreased. In contrast, when larvae were subjected to the diapause induction treatment only during the periods from the hatching stage to the 2nd, 3rd, and 4th instar, almost all larvae were not induced to diapause. The results suggest that the early age of the 5th larval instar is the last stage for sensitivity to diapause induction stimuli. In the diapause-induced larvae, hemolymph trehalose content increased and body supercooling points dropped, compared with those in non-diapause larvae.

• Korean journal of applied entomology
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• v.59 no.3
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• pp.243-250
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• 2020

Two meridic diets, N4 and N6, containing pinto bean, wheat germ, soybean, whole milk and sucrose as main nutrients were developed for rearing Spodoptera frugiperda (Noctuidae) larvae. Six larval instars were observed when neonate larvae were individually raised on these diets in small petri-dishes (ø 50 × 10 mm, 19.6 ㎤) at 25℃ and 15:9 h (light:dark) photoperiod. The average pupation rate of 97.8% on the N4 diet was significantly higher than the rate of 85.6% on N6 diet. The emergence rates were 92.0% on N4 diet and 93.5% on N6 diet, with a non-significant difference. The larval periods were 17.9 and 17.7 days for females, and 18.7 and 18.5 days for males, for N4 and N6 diets, respectively, with non-significant differences between diets and sexes. The pupal periods on both diets were identical (11.1 days for females and 12.8 days for males), despite differences between sexes. The pupal weights of both sexes on N4 diet were identical with a value of 257 mg, whereas those on N6 diet were 256 and 263 mg for females and males, respectively, with a non-significant difference. The longevity of female adults that emerged on N6 diet was 13.8 days and longer than 8.6 days on N4 diet. The pre-oviposition periods were 5.0 and 4.2 days on the N4 and N6 diets, respectively, with a non-significant difference, however, the oviposition period of 6.5 days on N6 diet was longer than the period of 3.9 days on N4 diet. The effective fecundity on N6 diet was 1,392 eggs (maximum 1,776) and was higher than that of 942 eggs (maximum 1,694) on N4 diet, with a non-significant difference. The egg hatching rates on N4 and N6 diets were 79.2 and 79.8%, and egg periods were 3.0 and 2.9 days, respectively, with non-significant differences.

• Korean journal of applied entomology
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• v.3
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• pp.31-39
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• 1964

The authors studied on the bionomics of the Florida wax scale, Ceroplastes floridensis Comstock and bionomics of two kind of parasites which attack on this Florida wax scale in 1963 to 1964. 1. Ceroplastes floridensis Comstock was heavily infested on the persimmon tree planted in the southern part of Korea, specially at the center of Taegu city. Parasitic ratio of important parasite of Ceroplastes floridensis Comstock, Microterys clauseni was $66.67\%$ and appeared low parasited ratio at the center of the city. 2. The developed eggs of the Ceroplastes floridensis Comstock was appear며 from mid-May to early July. The peak of it was late-May to early June. Average stored eggs inside of a body is 2030. $2030.77\pm0.49.$. 3. The hatching period of the Ceroplastes floridensis Comstock begins from early June to early July. Mid-June was the peak period of it. Pupation period of the male was August 14 to September 7 and adult was emerged on August 20 to September 8. Mean longevity for adult male was 3 days in August but 4 days in September. 4. On the differences of the body- length parasited on the three host plants, persimmon, platanus, and trifoliate orange, the body length parasited on the persimmon was the largest, medium on platanus and the smallest on the trifoliate orange. 5. Microterys clauseni H. Compere parasite on tile Ceroplastes floridensis Comstock with 5 generations in a year. Hibernate in the body of the host as tan·at stage. The first adult appears in middle April. Fifteen days was required for one generation in $21^{\circ}$. The authors observed on the form ovary, female with 6 ovarioles, and mean number of eggs per female was $47.19\pm0.55$. 6. On the parasited individuals of the Microterys clauseni H. Compere a larva was the most numerous and was found 2 individuals or 4 individuals parasite on the one Ceroplastes floridensis Comstock. 7. Coccophagus app. parasited on the only male body of the Ceroplastes floridensis Comstock. The parasitic ratio was $14.831\%$ on persimmon tree in Taegu city.

• The Korean Journal of Zoology
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• v.9 no.2
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• pp.12-20
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• 1966

Studies on the rate of growth, the rate of feeding and the efficiency of food conversion on the stage of new-born fries to the near adult size for three species of cuttlefishes , Sepia esculenta, Sepia subaculeata, Sepiella maindroni and two species of squids, Sepioteuthis lessomiana, Euprymna berryi were carried out in the process of artificial raising, and then argued about a feasibility of the propagation of cuttlefishes and squids. 1. The relation between the daily age (D) and the body weight(W) of Sepia exculent is expressed in a logarithmic equation, log W=3.0649 log D-4.2768. The daily rates of growth through 121 days of the raising period were 1.46 per cent for the man시 length and 1.67 percent for the body weight. The raipidest growth of Sepia esculenta is observed at the stage of 1 to 4 cm in the mantle length . At that time the daily rates of growth reach 3.3 to 5.5 percent for the mantle length and 10.4 to 12.0 percent for the body weight, respectively. The growth of Sepia esculenta varies a great deal to the bait. When fed on a dead bait the rates of growth decrease 17 per cent for the mantle length and 26 percent for the body weight compared with those fed on a live bait. 2. The relation between the daily age and the body weight of Sepia subaculeata is expressed in a logarithmic equation, log W=3.7447 log D-4.9003. The daily rates of growth through 110 days of the raising period were 1.63 percent for the mantle length and 1.83 percent for the body weight. The rapidest growth of Selia subaculeata is observed at the stage of 1.5 to 9.0 cm in the mantle length. At that time the daily rates of growth reach 3.1 to 7.4 percent for the mantle length and 6.8 to 16.7 percent for the body weight , respectively. 3. The relation between tehdaily age and the body weight of Sepiella maindroni is expressed in a ogarithmic equation , log W=2.9332 log D-3.8224 . The daily rates of growth through 133 days of the rearing period were 1.39 percent for the mantle length and 1.51 percent for the body weight . The rapidest growth of Sepiella maindroni is observed at the stage of 0.4 to 5.8 cm in the mantle length. At that time the daily rates for growth reach 4.6 to 7.3 percent for the mantle length and 8.5 to 15.4 percent for the body weight , respectively. 4. The daily rates of growth onthe stage of 0.5 to 6.0 comin the mantle length of Sepioteuthis lessoniana were 4.1 to 5.9 percent for the mantle length and 7.1 to 10.7 percent for the body weight . 5. During the rearing period of 31 days immediately after the hatching , the daily rateof feeding of Sepia esculenta marked 11.0 to 39.4 percent (28.2 percent in an average), and the efficiency of food conversion of this species reached 9.0 to 71.0percent (38.7percent in an average). Even at the more growing stage of 4.5to 6.2 cm in the mantle length, the daily rate of feeding of three species of cuttlefishes wee maintained 17.7 percent for Sepia esculenta, 30.8 percent for Sepia subaculeata and 34.7percent for Sepiella maindroni on an average. 6. The efficiency of food coversion of cuttlefishes and squids are larger than those of other fishes, and all the species are rapid in their growth. Four to five months are thought to be enough for their growing into a fair commercial size.

• Journal of Embryo Transfer
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• v.29 no.3
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• pp.241-248
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• 2014

This study was carried out to evaluate the effects of embryonic stage, cryoprotectant, and freezing-thawing method on the rates of survival and development of the cryopreserved mouse early embryo and finally to establish the cryopreservation method of surplus embryos obtained during assisted reproductive technology (ART). Two to eight cell embryos were obtained from oviducts of mated $F_1$ hybrid female mice superovulated by PMSG and hCG. Two-step EG, DMSO and 4-step EG, DMSO were used as cryoprotectant and dehydration and rehydration method of embryos, and slow-cooling or rapid-cooling method was used as frozen program. The survival rates of embryos were measured after thawing and rehydration, and the developmental rates of embryos were compared and observed during culturing embryos for 24, 48, 72, 96 hrs. As for the survival and development rates of embryos according to embryonic stage, the survival rate of 2 cell stage in EG and DMSO was significantly higher than 4~8 cell (65.4% versus 61.2%, 81.1% versus 72.5%) (p<0.01, p<0.01), but the development rates of 4~8 cell embryos in EG and DMSO were significantly higher than 2 cell embryos for whole culture period (p<0.01) and the development rates of 4~8 cell embryos in EG were significantly higher than 2 cell embryos in DMSO (p<0.01). As for the survival and development rates of embryos according to cryoprotectant, the survival rate of 2 cell embryo in DMSO was significantly higher than that in EG(77.0% versus 64.4%) (p<0.01), whereas the development rate of embryos was not differ till 24 hrs. The development rate from morular to hatching blastocyst, however, was sinificantly higher in EG than in DMSO during 48 hr (p<0.01). The survival rate of 4~8 cell embryo was 62.5% in EG and 73.3% in DMSO. The development rates of embryo in EG were significantly higher for whole culture periods (p<0.01, 0.05). In respect to the effect of freezing and thawing program on the survival and development rates of embryos, method of slow cooling and rapid thawing was more effective than that of rapid cooling and rapid thawing. The survival rate of embryo in 2 cell stage was higher than in 4~8 cell stage, and EG appears more effective cryoprotectant than DMSO because EG showed better development rates of embryos in 2 and 4~8 cell stage. Moreover, slow cooling and rapid thawing method was considered as the best cryopreservation program.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.2
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• pp.211-216
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• 1997

The present study was carried out to evaluate whether the coculture system of human embryos with Vero cells can improve the quality of embryo or overcome the repetitive implantation failures in order to obtain pregnancy. From January to December 1996, a total 202 cases which patients with the problems of repetitive implantation failures (group I) or those with the poor embryonic quality in their previous cycles (group II) was analysed. The quality of cocultured embryo, pregnancy, on-going and implantation rates between coculture and control groups were compared. Of 93 cases in group I, coculture was performed in 34 cases and conventional IVF for the rest. Of 109 cases in group II, 36 for coculture and 73 for conventional IVF. In group I, pregnancy, on-going and implantation rates in coculture group (14/34 (41.2%), 9/34 (26.5%), 16/81 (19.8%), respectively) were higher than those of control (11/59 (18.6%), 8/59 (13.6%), 12/152 (7.9%), respectively). There is significance in the pregnancy and implantation rates (p=0.028 and p=0.015). In group II, pregnancy, on-going and implantation rates in coculture group (8/36 (22.2%), 5/36 (13.9%), 8/87 (9.2%), respectively) were higher than those of control (5/73 (6.8%), 3/73 (4.1%), 3/158 (1.9%), respectively). Like the result of group I, there is significance in the pregnancy and implantation rates (p=0.028 and p=0.022). Coculture system with Vero cells works well in the groups of the two indications. Although the case of 3 day-coculture was small as 15 cases in group II, 3 day-coculture improved pregnancy rate (4/15 (26.7%)). Therefore, 3 day-coculture with assisted hatching is recommended to the patients with poor embryonic quality. In conclusion, coculture system with Vero cells can be suggested as an effective method which improves pregnancy rate in those who have repetitive implantation failures or whose embryonic quality was poor in their previous cycles.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.403-415
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• 2021

Seasonal development of Parthenolecanium corni was observed from 4 Jun. 2019 (nymph) - 25 Jun. 2020 (1^st Gen. nymph) in blueberry shrub in Sacheon city, Gyeongsangnam-do. To investigate their development, more than 5 twigs sprouted in 2018 were taken from the farm nearly weekly basis. The development of each scale were examined under the stereomicroscope and chemical control was conducted in the blueberry shrub with available three insecticides. The results on the development period and Centigrade Degree-Days accumulation (DDC) obtained are as follows: egg-laying period (peak): 12 -26 May 2020 (24 May)(DDC, 110.0-188.5 (173.6)); egg-hatching period (peak): 9 - 23 June 2020 (19 June)(DDC, 325.2-480.8(435.6); egg period: 26 days; nymph movement from overwintered adult to new leaves 16-25 June 2020 (DDC, 410,5-500.4); nymph movement from leaf to twig (peak) to become adult: 4-18 Feb. 2020 (8 Feb.). Eggs no. /adult (range): 956.8 ± 73.4 (13 - 3497). Size (mm) of egg, 0.29 ± 0.020(L), 0.15 ± 0.013(W); of egg-hatched nymph, 0.35 ± 0.018(L), 0.18 ± 0.007(W), 0.09 ± 0.007(eye distance); and of adult, 4.30 ± 0.893(L), 2.64 ± 0.520(W). The egg-hatched nymphs from the overwintered adult moved to the backside leaf of new shoot in which they found about 95% until leaf is falling by early February in next year. They overwintered as 2^nd instar and occurred univoltine. For the control of the 1^st instar crawler, three insecticides treated on 16 and 30 July at the registered dose for Ceroplastes japonicus. Acetamiprid 8WP showed 96.9% mortality at 21 days after 1^st treatment.

• Korean Journal of Ichthyology
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• v.31 no.1
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• pp.7-15
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• 2019

The present study aimed to investigate the influence of starvation on growth, survival and swimming ability of Pacific cod Gadus macrocephalus larvae. Notochord length, musculature height, body depth, gut height and volume of yolk of reared larvae were measured to determine the growth parameters. A significant difference was observed in all morphometric characteristics before 15 DAH (days after hatching). Body depth and volume of yolk of unfed larvae were significantly smaller than those of fed larvae from 9 DAH (P<0.05). Almost all yolk in fed group was consumed at 11 DAH. Survival and growth of larvae were observed to determine the effect of delayed initial feeding (2 DAH, 3 DAH, 4 DAH, unfed). All larvae in the unfed group died by 15 DAH and the larvae in other experimental groups survived until the end of the experiment to 21 DAH. Survival rate was not significantly different between the 2 DAH group ($17.5{\pm}4.27%$) and the 3 DAH group ($20.5{\pm}1.5%$) at 21 DAH (P>0.05). However, there was a significant difference in survival rate between the 3 DAH group and the 4 DAH group ($11.7{\pm}1.52%$) (P<0.05). There was no significant difference in notochord length among the groups fed from 2 DAH, 3 DAH and 4 DAH at 21 DAH (P>0.05). The swimming ability in fed group gradually increased in both cruising and burst swimming speeds, while those abilities in unfed group gradually decreased after reaching the peak at 6 DAH in both cruise ($18.7{\pm}6.56mm/s$) and burst swimming speed ($43.5{\pm}12.65mm/s$).

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.1
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• pp.76-87
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• 2019

The purpose of this study was to evaluate the performance of and to derive future maintenance-management measures of the constructed alternative habitat for the Kaloula borealis at the University of Seoul, examining the period between 2015-2017. The research was constructed in 2014 and in a $191m^2$ area. The performance evaluation was divided into maintaining the habitat of the target species, maintaining the population and reproduction rates of the target species, maintaining the habitat of the wild species, the resilience of natural ecosystems, and the harmony with the surrounding environment. In terms of maintaining the habitat of the target species, soil collected from the existing habitat of the Kaloula borealis and was the depth was increased to 30cm in the alternative habitat. An artificial water supply was required every year during the supporting the spawning and hatching of other amphibians along with the Kaloula borealis. The sources of water of the alternative habitat were both rain and tap water, as it cannot be maintained naturally. Additionally, the Kaloula borealis thrived because it inhabited the research site and the average temperature was $26.2^{\circ}C$ from April-June, which is when the Kaloula borealis spawns. In terms of maintaining the population and reproduction rates of the Kaloula borealis, they were evaluated to have stable rates of reproduction. In terms of maintaining the habitat of the wild species, studies on vegetation and the structure of the characteristics of prey or predators will be needed. Also, alien species, such as Humulus japonicus and Bidens frondosa needed to be removed to maintain the wetland ecosystem of the wild species. In the assessment of the resilience of the natural ecosystems, the mud was monitored, noting the changes in the depth of water, with steps taken to reduce the leakage of water. The mud collected from the Haneul Pond wetland, which is located around the research site was piled up. Also, partial mowing management and the inducement of a natural vegetation colony was required for vegetation management. It was also necessary to create porous spaces, such as old trees and tree branches to create a habitat with hiding places and feeding and spawning places for small organisms. In terms of the harmony with the surrounding environment, the following threat factors needed to be managed: amphibian roadkill by vehicles and pedestrians and artificial draining due to nearby user access. Based on the monitoring results, alternative habitat management measures presented the promoting various waterside structures, in which amphibians can spawn and hide in, managing the water environment consistently, managing the vegetation, focused on the habitat of the wild species, and managing the surrounding environment for the habitat. The creation of an alternative habitat should be managed through monitoring, reflecting the characteristics of the changes in the site. Also continuing efforts are also needed to improve the habitat of the target species.

• Korean journal of applied entomology
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• v.61 no.2
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• pp.377-385
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• 2022

Most pruning branches of mulberry, Korean raspberry (bokbunja), and blueberries are discarded without use. These discarded pruning branches were utilized as feed in the investigation of the development and oviposition characteristics of Protaetia brevitarsis with a focus on breeding possibilities. It was observed that the developmental period of P. brevitarsis larvae fed with berry fermented sawdust from mulberry, bokbunja, and blueberry was shortened to 157.3 130.3 days, and 140 days, respectively, compared to 169.3 days for those fed with oak fermented sawdust. The weight and survival rate of the larvae also increased. Under all three types of fermented sawdust feed, the percentage of larvae with weight ≧ 2.5 g during the group was over 60% between 6-8 weeks after hatching; however under oak fermented sawdust feed, it was within 10%, and the percentage only increased after 10 weeks. The average number of eggs laid per female was ≧ 80, with an average oviposition period of approximately 9 weeks; however, there was no significant difference owing to the large deviation per individual. Furthermore, mixed fermented sawdust from the three berries enhanced the growth rate of larvae, and there was no difference in the number of eggs laid compared to those fed with control oak fermented sawdust. Our study demonstrates berry fermentation sawdust is just as effective as oak fermentation sawdust in the breeding of P. brevitarsis.