• Korean Journal of Medicinal Crop Science
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• v.27 no.4
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• pp.271-277
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• 2019

Background: Rehmannia glutinosa (Gaertn.) Libosch. ex Steud. has long been used as a traditional medicinal plant in Korea. This study was carried out to investigate the emergence conditions during the seedling periods in R. glutinosa. Methods and Results: The rhizomes of R. glutinosa variety (Jihwang 1) were harvested in the 22, March, 2018. The rhizomes were sown on in 50-cell plug trays. The emergence rates of seedlings at $15^{\circ}C$, $20^{\circ}C$, $25-40^{\circ}C$, and $45^{\circ}C$ treatment seedling were 1.3%, 96%, 100% and 0%, respectively. Rhizome rot was occurred at the temperature of $15^{\circ}C$ and $45^{\circ}C$. The emergence rates of seedlings in high moisture (HM), moderate moisture (MM) and low moisture (LM) treatments at $35^{\circ}C$ were 99.3%, 100%, and 0%, respectively. Drought damage was recorded in plant with the LM treatment. Seedling quality surveys were carried out at 10-days intervals from 10 to 60 days after sowing (DAS). Leaf length and leaf width were increasing until 50 DAS and the number of leaves was increasing until 60 DAS. Root length was increasing until 40 DAS, and then, flowering occurred from 30 to 60 DAS. Lastly, at 40 DAS, leaf aging and root enlargement was observed. Conclusions: We concluded that the emergence of seedlings was possible in the range of 20 to $40^{\circ}C$. Considering drying and rotting damage, we concluded that the moderate level of moisture is most appropriate for seedling emergence. In addition, we concluded that optimal seedling periods are between 30 and 40 DAS.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.161-163
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• 2000

To assess effects of cold treatment on pupation and emergence of the mulberry longicorn beetle, Apriona germari, the larvae, which ceased feeding, were exposed to three different temperature regimes (2.5, 5 and 7.5$^{\circ}C$) and preservation periods (50, 80, and l10 days). The results indicated that pupation and emergence rates of A. germari were highest at $7.5^{\circ}C$ for 110 days, 40.7% and 37.0%, respectively, demonstrating that the effect of cold treatment on metamorphosis was approximately 3 to 4 fold stronger than that of nontreatment.

• Journal of Life Science
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• v.7 no.4
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• pp.347-354
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• 1997

Some attempts were made to investigate the gentic characteristics of the brown planthopper(BPH), Nilaparvata lugens Sta${\aa}$l, biotypes. In terms of egg and nymphal periods, egg hatcgability, emergence ratio, and population change of BPH and plant damage of rice cultivars by the infestation of BPH biotypes and their hybrid progenies in field conditions. The egg and nymphal periods of the three of BPH biotypes and their hybrid progenies on Dongjinbyeo with no resistance gene were shorter than on rice cultivars with resistance gene. But the periods of biotype-2(♀) X 2(♂) (E) on Samgangbyeo with Bph-1 gene and biotype-3(♀) X 3(♂)(I) on Mirying 63 with bph-2 gene were as short as on Dongjinbyeo. The egg hatchability and emergence ratio of the three Bph biotypes and their hybrid progenies on Dongjinbyeo were higher than on the other rice cultivars, and those of E on Samgangbyeo and I on Miryang 63 were as high as on Dongjinbyeo. In rice paddy field, biotype-1(♀) X 1(♂)(A)$\sim$I infested on Dongjinbyeo, E onSamgangbyeo, and I on Miryang 63 were increased their population densities remarkably in next generation. Dongjinbyeo infested by A$\sim$I, and Myryang 63 infested by I were hopperburned at 60 days after infestation and had a damage rating of 0.9. But Samgangbyeo infested by E was no hopperburn(damage rating: 7.3) though it showed high BPH population at 60 days after infestation.

• Korean journal of applied entomology
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• v.42 no.3
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• pp.241-248
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• 2003

The aphid-eating gall-midge, Aphidoletes aphidimyza (Rondani), as predator of aphids was wildly used as one of the biological control agents for control of several kinds of aphids. Their some kinds of biological characteristics were examined. The developmental periods of A. aphidimyza from egg to adult with the green peach aphid as prey were 40 and 12 days at 15$^{\circ}C$ and 30$^{\circ}C$, respectively. Supplying the cotton aphid as prey, their developmental periods were shorter than with the green peach aphid. In case of the preservation of pupa in the cold condition, emergence rates were over 90% for 1 and 2 weeks at 5$^{\circ}C$ and l0$^{\circ}C$, respectively. Adult females of A. aphidimyza began mating and laying eggs at 2-3 days after emergence, and they laid about 200 eggs for lo days of average life span. Most of adults were emerged from pupa at 6 to 8 pm during a day, and they mainly acted in the early night.

• Korean journal of applied entomology
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• v.25 no.1 s.66
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• pp.11-16
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• 1986

Local difference in post-overwinter developmental periods was investigated by incubating the overwintered larvae collected from 8 locations at $25^{\circ}C$ begining January 15 and February 15. Based on the 2nd incubation test, it was found that Chunseong colony had the shortest pre pupal period of 17.9 days, while Gwangsan colony had the longest 27.7 days. In general, prepupal period showed negative correlation with latitudes. Average pupal periods were not significantly different among colonies. Adult emergence period showed the same trend as prepupal periods. Chunseong and Pyeongtaeg colonies emerged faster than the other colonies and showed a single peak of adult emergence, while Nonsan, Iri, Gwangsan colony showed several peaks of adult emergence.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.473-477
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• 2021

An artificial diet containing wheat germ, soybean, corn, yeast, sucrose, casein, cholesterol, 𝛽-sitosterol, and dry Miscanthus sacchariflorus stem powder was developed for rearing Chilo suppressalis (Crambidae) larvae. Neonate larvae were individually raised on the diet till adult emergence at 25℃ and 15:9 h light:dark photoperiod. In the results, the pupation and the emergence rates were 82.2% and 98.6%, respectively. The mean developmental periods of female and male larvae were 34.6 days and 31.0 days, respectively, whereas the pupal periods of female and male were 8.9 days and 9.7 days, respectively. Those periods were significantly different between genders. The mean pupal weights of female and male were 75.0 mg and 57.0 mg, respectively, with significant difference.

• 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.31 no.1
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• pp.33-36
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• 1992

To establish the succeeding generations of wild silkworms, Bombyx mandarina Moore, massrearing was made in the laboratory. The rearing result was good under high humidity and moderately warm condition. Larval periods were 15 to 25 days and the most of larval period was around 17 days. The pupation rate and the pupal period of most of males and females were 40% and 13 to 25 days, respectively. There were two emergence peaks of males and females, and males emergence peak occurred two or three days faster than females.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.525-532
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• 1995

The periods of germination and seedling emergence, epidermal cell size and the activities of peroxidase and amylase of 6 rice cultivars were examined to clarify the response to 3 temperature conditions, constant temperatures of 27$^{\circ}C$ and 17$^{\circ}C$ and alternating temperature of 24/1$0^{\circ}C$, in the dark condition. The periods of germination and seedling emergence were increased and the germination was delayed greater than the seedling emergence under 17$^{\circ}C$ and 24/l$0^{\circ}C$, compared with 27$^{\circ}C$. Lengths of epidermal cell of coleoptile and first leaf were reduced, but the widths were increased in the 17$^{\circ}C$ and 24/1$0^{\circ}C$, compared with 27$^{\circ}C$. The activities of peroxidase in the emerging shoots and amylase in the germinating seeds were reduced in 17$^{\circ}C$ and 24/1$0^{\circ}C$. There were significant correlations between peroxidase activities and the widths of epidemal cell of first leaf and between amylase activities and periods of germination. Varietal differences of all observations were remarkable in 17$^{\circ}C$ and 24 /1$0^{\circ}C$.

• Entomological Research
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• v.48 no.6
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• pp.550-558
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• 2018

To develop a system for the mass production of Protaetia brevitarsislarvae (Pbl), this study analyzed the oviposition characteristics of third instar Pbl through successive rearing and cold treatments. In the first generation, females laid 50 eggs each on average, and spawned higher numbers of eggs for the first 5 days but then fewer after this. However, all of the $2^{nd}$-generation females that were produced through the successive rearing of eggs from the $1^{st}$ generation did not spawn. When test insects (TI) were raised at $32^{\circ}C$, their $mean{\pm}SE$ pupal period and emergence rate were $28.4{\pm}1.9$ days and 87%, respectively. However, most individuals raised in cold treatments ($5^{\circ}C$ and $-5^{\circ}C$) without a pre-cooling period did not survive. Individuals exposed to a pre-cooling period, however, had a 7-10 days longer pupal period than those raised at $32^{\circ}C$, and their emergence rate (90%) was slightly higher. Different cold treatment temperatures ($0^{\circ}C$, $3^{\circ}C$, or $5^{\circ}C$) and periods (30 or 60 days) were tested in further experiments. The experimental group kept for 30 days at $0^{\circ}C$ and $3^{\circ}C$ had the shortest pupal period of all, and emergence rates exceeded 90% in most groups. With respect to the number of eggs spawned by the second generation females after cold treatments, the experimental groups held in cold treatments at $5^{\circ}C$ for 30 and 60 days were found to spawn the most eggs. Consequently, the experimental group kept at $5^{\circ}C$ for 30 days was the most effective set of conditions tested during the entire breeding period.