• Korean journal of applied entomology
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• v.46 no.3
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• pp.385-392
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• 2007

This research was carried out to develop economical artificial diets of the greater wax moth, Galleria mellonella (L.). Diets were mixed with malt or sugar instead of whole honey for cheaper ones. fecundity, developmental period, pupation rate, emergence rate and adult longevity of G. mellonella depending on diet were examined. The head width and length of larvae were not significantly different among diets tested. However, the weight of larva was the heaviest, 255.5 mg, at 1/2 honey + 1/2 malt diet and lightest, 144.3 mg, at sugar diet. The weight of pupa was also the heaviest at 1/2 honey + 1/2 malt representing 196.7 mg. Larval period was the shortest at honey diet as 30.9 days but the longest at sugar diet as 36.5 days. Pupation and emergence rates were over 79.3% at all diets. The longevity of mated females was ranged from 6.3 to 8.0 days and those of mated males ranged from 7.9 to 11.2 days. The highest number of eggs, 1269, was obtained at sugar diet. Artificial diets replaced by rice bran, malt, and sucrose reduced costs compared with wheat bran plus honey diet. The cost of rice bran was only 10% of wheat bran. Honey was much more expensive than malt and sugar, that is 6 and 13 times, respectively.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.393-399
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• 2007

Two lepidopteran species, Matsumuraeses phaseoli (Matsumura) and Maruca vitrata (syn. M. testulalis) (Fabricius) were reared on artificial diets, and analyzed in their developmental characteristics. Photoperiod was supplied with 16L/8D for M. phaseoli and with 13L/11D for M. vitrata, respectively. Both species passed five larval instars with discrete sizes of head capsule width. In a constant environment ($25^{\circ}C$ and 65%RH), the developmental period of M. phaseoli egg, larva and pupa was 3.9, ca. 16.0 and 8.9 days, respectively, and over 80% of M. phaseoli larvae could develop into pupae, most of which emerged into adults. Newly laid eggs could be stored at $5^{\circ}C$ for 15 days with over 50% hatchability. Similar developmental traits were shown in M. vitrata. However, a low temperature preservation was not applicable to M. vitrata eggs.

• Korean journal of applied entomology
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• v.58 no.1
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• pp.77-83
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• 2019

This study was conducted to investigate the developmental characteristics of Propylea japonica Thunberg (Coleoptera: Coccinellidae) and its consumption of Myzus persicae nymphs at 3 constant temperatures (20.0, 25.0 and $30.0^{\circ}C$; $60{\pm}5%$ relative humidity; 14 h light : 10 h dark). The longevity of adult female P. japonica under 20, 25, and $30^{\circ}C$ was 134.0, 101.0 and 55.2 days, respectively. The total fecundity was 508.6, 875.6, and 383.4 eggs during its life span, respectively. The longevity of adult male P. japonica under 20, 25, and $30^{\circ}C$ was 128.8, 97.8, and 46.5 days, respectively. Average daily consumption of adult M. persicae by 1st, 2nd, 3rd, and 4th instar P. japonica at $25^{\circ}C$ was 2.2, 7.3, 14.5, and 29.1, respectively. The average daily number of M. persicae consumed by male and female P. japonica over their lifetimes was 35.0 and 42.9, respectively. Average daily consumption of adult Aphis gossypii by 1st-4th instar P. japonica at $25^{\circ}C$ was 2.2, 7.5, 13.9, and 29.5, respectively. The average daily number of A. gossypii consumed by male and female P. japonica over their lifetimes was 37.0 and 40.8, respectively.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.203-212
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• 2004

A total of 1,200 eggs obtained from 312-day-old Hy-line Brown laying breeder hens and 319-day-old Hy-line Brown commercial laying hens (600 eggs obtained from each one) at same day were used to investigate the effects of egg storage, storage temperature, and insemination of hens on the change of albumen height, Haugh unit(HU), albumen pH, shell strength, and yolk color. Eggs were stored up to 14 days after lay at $3^{\circ}C$ or $10^{\circ}C$ and sampled one day after stored and then 24 hours interval. Longer periods of storage resulted in lower albumen height and HU at both storage temperatures, but in higher albumen pH. The eggs stored at $3^{\circ}C$ were significantly (P<0.05) higher in HU and lower in albumen pH than the ones stored at $10^{\circ}C$. The eggs obtained from the non-inseminated-hens were significantly (P<0.05) higher in albumen height, HU, and albumen pH than the eggs obtained from the inseminated-hens. Whereas, the eggs obtained from the non-inseminated-hens in the mean albumen pH of eggs stored at $3^{\circ}C$ were significantly (P<0.05) higher than the ones obtained from the inseminated-hens, but the mean albumen pH of eggs stored at 10^{\circ}C did not differ each other. The mean shell strength of the eggs obtained from the inseminated-hens was significantly (P<0.05) stronger than that of the eggs obtained from the non-inseminated-hens at both storage temperatures. Albumen height and albumen pH were negatively correlated $(P<0.01\~0.001)$ in both inseminated and non-inseminated-hen's egg groups. The degree of yolk colors was not significantly changed overall of the experimental periods in both storage temperatures. The study suggests that the change of egg freshness such as albumen height and HU is relatively more associated with storage period and storage temperature than insemination or non-insemination of hens.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.321-327
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• 2019

When Aphidius colemani mummies were stored at four different temperatures (6, 8, 10 and 12 ± 1℃), they could be stored at 8℃ for 10 days with over 50% adult emergence. A number of mummies of Rhopalosiphum padi parasitized by A. colemani adults emerged from mummies after 8℃ storage clearly reduced with increasing duration of storage and especially declined with storage longer than 13 days showing < 20% parasitism. However, there were no differences in aphid parasitisms by A. colemani on 3 to 10 days after storage. Over 3 day storage at 8℃ was adversely affected on survival of A. colemani adults. Therefore, cold storage of A. colemani adults is considered as an unsuitable method for mass production of biological control agent. When 2-day-old Meteorus pulchricornis cocoons were stored at 6, 8 and 10 ± 1℃, it was possible to be stored up to 63 days at 8℃, showing the highest emergence. With increasing of cold storage duration at 8℃, parasitism on 2^nd and 3^rd larval instar of Spodoptera litura by stored M. pulchricornis significantly reduced. However, parasitic rate by M. pulchricornis stored for 2 weeks was similar to that by 1 week stored ones. Therefore, M. pulchricornis cocoons could be stored up to 2 weeks at 8℃ for stockpiling before release.

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.89-94
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• 2002

This study was performed to evaluate effects of different holding temperatures and storing periods during the pre-incubation period on egg hatchability of hens egg in broiler breeders. For the treatments 1(T1)~7(T7), which were stored fur 1(T1) to 7 days(T7) before egg incubation, respectively. There were three replicates per treatment and forty eggs per replicate. This study was performed twice, which were 40(Summer) and 50 weeks of age(Autumn) in broiler breeders. Storing ambient temperature of egg, egg weight, at 0 and 18 days during incubation, fertility, hatchability and embryo mortality were examined. Average hatchability was rapidly decreased only in Summer. Although it was not significantly different in Autumn. This experiment was concluded that storing periods of hatchery egg was influenced hatchability, especially in high ambient temperature conditions(Summer, above $25^{\circ}C$ ). In conclusion, we found out that optimum hatchability can be achieved with a storage temperature of 13 ~$19^{\circ}C$ for broiler breeder eggs stored for up to 7 days.

• Korean Journal of Ichthyology
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• v.32 no.2
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• pp.63-69
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• 2020

This study investigated spawning characteristics of Hangang bitterling, Rhodeus pseudosericeus inside the host mussel, Unio douglasiae sinuolatus at the Heukcheon Stream in Korea from April to June 2017. 327 mussels were collected, among them, 34 (14.1%) were spawned mussels of R. pseudosericeus with glochidia. The mean number of R. pseudosericeus embryos with or without glochidia by the mussel gill position was 5.0±3.58 (range, 1~8) vs. 2.8±2.13 (1~9) in the left outer demibranch, 1.5±0.96 (1~3) vs. 1.7±0.82 (1~3) in the left inner demibranch, 1.4±0.51 (1~2) vs. 2.1±1.85 (1~6) in the right inner demibranch, and 6.4±4.82 (1~20) vs. 3.0±1.86 (1~6) in the right outer demibranch. The frequency of R. pseudosericeus embryos with or without glochidia by the mussel gill position was 82.6% vs. 73.4% in the left outer demibranch, 17.4% vs. 9.4% in the left inner demibranch, 26.1% vs. 15.6% in the right inner demibranch, and 58.7% vs. 67.2% in the right outer demibranch. The mean number of R. pseudosericeus embryos with or without glochidia was 8.5±6.43 (1~23) vs. 4.5±3.38 (1~14). The number and frequency of R. pseudosericeus embryos were higher in the mussel with glochidia and the outer demibranchs than those without glochidia and with inner demibranchs.

• Korean Journal of Environment and Ecology
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• v.30 no.6
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• pp.977-985
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• 2016

The captive breeding program of the Reeve's turtle (Mauremys reevesii), which is designated as an endangered category II species by the Korean Ministry of Environment, has developed, but the reproductive physiology of the species is still not fully understood. In this study, we investigated seasonal changes in the sex steroid levels, the number and size of follicles and eggs and male-female interactive behaviors of hibernated and non-hibernated turtles between November 2014 and October 2015. Plasma estradiol level in females increased from July and peaked in the period from August to October. Plasma testosterone level in males peaked between August and September and was the lowest in March, although there were some variations depending on the patterns of hibernation. Hibernated females had fully developed eggs between early May and middle July and laid eggs between early June and late July, but non-hibernated females had eggs between early April and early June and also between middle August and late November, and laid eggs in early June, mid-October, and early February. These results suggest that hibernation could be essential for normal follicular and egg developments. Male-female interactive behaviors including courtship intensified from late August and peaked in October and November. Our findings suggest that mating period of this species is directly related to increased steroid hormone levels, but follicular and egg developments in females are not. Our results could be very useful to the successful operation of captive rearing programs of the endangered Reeve' sturtles.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.1
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• pp.11-19
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• 2002

We studied the characteristics of catch fluctuation and distribution of yellow tail resources in Korean Waters from 1991 to 2000. The obtained results are summarized as follow, The distribution of yellow tail resources in Korean Waters was showed by mooving north-ward groups from Spring to Autumn and south-ward groups from Autumn to Winter with they passed Winter and spawned from the south of Jeju Island and Tsushima current. Therefore, the fishing ground of yellow tail by handline fishing around Marado targets a school of yellow tails which migrate south-ward so as to winter and spawn.

• Korean journal of applied entomology
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• v.18 no.1 s.38
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• pp.15-21
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• 1979

To determine the population regulation mechanism of the Green rice leafhopper (Nephotettix cincticeps Uhler), the responses of the population increase to initial densities and the effect of host conditions and temperatures during developmental period were investigated. In the out door experiment, the increasing ratio of population density of this pest was reduced as initial density increased and this density-dependent effect was differ in accordance with host condition. Host conditioning through feeding resulted in reduction in numbers of eggs produced and it seemed to be affected by some inhibiting materials secreted by the pest during feeding. though the direct effect of feeding can't be excluded. The population growth was related with population density and host stage. Thus in late planted units, the host stage was favourable to the growth of population at low initial insect density but unfavourable at relatively high initial insect density and in early planted units, vice versa. The temperature during developmental stages definitely affected the determination of sex ratio of adult population and reduced numbers of eggs produced. The most favourable temperature to the population increase was $290^{\circ}C$, and at high temperature, $33^{\circ}C$, severe reduction of fecundity was shown ana it seemed to be caused by the simple reduction in numbers of eggs produced.