• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.74-77
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• 1999

The object of this study is to determine the effect of priming on the germination ability and seedling emergence of aged soybean seeds in lab and field conditions. Artificial or natural procedure for seed aging was applied in this study. One seed lot was artificially aged for 3 to 5 days at 42$^{\circ}C$ with high relative humidity (nearly RH 100%), and the other one was stored at room temperature for 17 months. Aged seeds were osmoconditioned in -1.1 MPa polyethylene glycol 8000 (PEG) solution for 3 days at $25^{\circ}C$ and air-dried. When Danyeobkong was aged for 4 days average germination was 61.5%, however, this improved to 98.5% after the priming treatment. Improvement of seed germination by priming the aged seed was consistent with large seed sized Jangyeobkong cultivar, indicating that the priming was effective in enhancing seed germinability regardless of seed size. Priming aged seeds also resulted in good stand establishment in the field trials. Germination of aged seeds of Danyeobkong without priming was 17.0%, whereas that of primed ones was 66.4%.

• Korean Journal of Medicinal Crop Science
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• v.7 no.1
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• pp.16-21
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• 1999

Seed-propagation of Solomon's seal (Polygonatum odoratum) takes 2 years to shorten the period for becoming a practical method. The experiment was done to establish a proper method of breaking the epicotyl dormancy in bulk seed-propagation. Seedlings with a bulbil were treated with $GA_3$ every 2 days for 4 or 8 days and chilling treatments at $3^{\circ}C$ were enforced for 4, 6, 8 or 12 weeks. Emergence- and growth-related characteristics were examined immediately after the treatments, 3 and 6 weeks later. Rate of cotyledonary sheath rupture immediately after $GA_3$ treatment was greater in its 8-day treatment than in 4-day although its effect disappeared later. However, any epicotyl treated with $GA_3$ solution did not elongate so that new seedlings disemerged over the bed soil. That resulted from not breaking the epicotyl dormancy since $GA_3$ did not rupture all of the cotyledonary sheath formed with several sheets and consequently, the solution did not reach it. The $GA_3$ treatment for bulk seed-propagation, therefore, was impractical method. On the contrary, the chilling treatment was able to be applied to the seed-propagation because of getting the cotyledonary sheath rupture and the epicotyl elongation. Seedling emergence and its growth after chilling treatment were influenced by chilling period although required at least over 6-week treatment for satisfactory results.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.114-119
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• 2005

Larval survivorships, growth rates, developmental rates, and emergence rates of Cloeon dipterum were studied under four constant temperatures $(10^{\circ}C,\; 15^{\circ}C,\;20^{\circ}C,\;and\;25^{\circ}C)$ in the laboratory. Larval mortalities were relatively higher during the initial one-week period, but those tend to be stabilized as the experiments proceed. Judging from the growth and develop-mental rates, estimated optimal temperature for larval growth and development lies between $20^{\circ}C\;and\;25^{\circ}C$. Estimated larval period for emergence is less than 100 days.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.94-99
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• 1991

The daily rhythm of sex pheromone production and release by females of the black pine base scale, Matsucoccus thunbergianae Miller and Park, was demonstrated by studying the amounts of pheromone possessed and released by females, periodically after emergence. Cycles of both pheromone production and release had daily peaks between 8 a.m. and 2 p.m., and has marked decreases after 4 p.m. It appeared that the amounts of pheromone gradually decreased three days after the emergence. Significance in synchronization of the daily rhythm of female pheromone release and activities of males and females with reference to reproductive success in this species is discussed.

• The Plant Pathology Journal
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• v.21 no.4
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• pp.391-394
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• 2005

Tomato seedlings (20- days old) were transplanted to infested soil with Orobanche cernua and non-infested soils. All plants were maintained under 0, 25, 50 and 75 mM NaCl soil salinity levels throughout their growing period under greenhouse conditions. Plants grown in O. cernua infested soil infIltrated with 0, 25, and 50 mM NaCl solution for salinity showed significant reduction in their growth as well as their total soluble carbohydrate and protein contents in compared with those grown in non-infested soil. However, under 75 mM NaCI salinity level all plants showed similar growth values whether they were grown in O. cernua infested or non-infested soil. Starting at the fifth and through out the eighth week after transplantation there was a significant increase in plant height in the 0, 25 and 50 mM NaCl irrigated plants over other treatments. Irrigation with 50 mM NaCl significantly reduced the emergence of O. cernua (2/plant) and the number of attachments (4.4 attachments) on roots of tomato. Furthermore, irrigation with 75 mM NaCl resulted in complete elimination of O. cernua emergence.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.267-275
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• 2003

To observe the effects of seed matriconditioning on the emergence, plumule growth, and seed physiological properties of normal and aged seeds of three corn(Zea mays L.) genotypes (dent, sugary, and shrunken-2), normal and artificially aged seeds were matriconditioned at 50, 75, 100, and 125% moisture contents of vermiculite at $25^{\circ}C$ for 24 hours and the germinability was examined at $25^{\circ}C$ and in cold test (7 days at 1$0^{\circ}C$followed by $25^{\circ}C$). Emergence rate, emergence speed, and plumule growth were smaller in the order of dent＞sugary＞shrunken-2. Matriconditioning did not affect the emergence rate of normal dent and sugary seeds, while it enhanced emergence speed and plumule growth. In contrast, the emergence rate, emergence speed, and plumule growth of normal shrunken-2 and aged seeds of all genotypes were enhanced as the moisture content of vermiculite increased up to 125% both at $25^{\circ}C$ and in cold test. Matriconditioning promoted $\alpha$-amylase activity and DNA and soluble protein contents, while it reduced the leakage of total sugars and electrolytes from the seeds when soaked in water.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.586-593
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• 2020

This study was conducted to investigate the biological characteristics of Phanuromyia ricaniae (Hemiptera: Platygastroidea), an egg parasitoid of Ricania sp. (Hemiptera: Ricaniidae) as a biological control agent to control Ricania sublimata. The developmental period of P. ricaniae was 3.8 days for eggs, 11.1 days for larvae, and 16.3 days for pupae at 25℃, and 3.4 days for eggs, 7.8 days for larvae, and 15.3 days for pupae at 30℃. Except for the larval stage, the developmental periods were not significantly different, but the egg-to-pupa period at 30℃ was significantly shorter than that at 25℃. P. ricaniae emerged at the photophase in 24 hours, but not at the scotophase. A higher emergence rate (34.5%) was seen from 10:00 to 12:00 after the lights were turned. The female-to-male ratio of P. ricaniae was 3:1. The longevity of P. ricaniae adults was 49.0 days for females and 44.0 days for males at 20℃, 27.6 days for females and 28.4 days for males at 25℃, and 18 days for females and 14.0 days for males at 30℃. Its longevity at a low temperature (20℃) was longer than that at higher temperatures (25 and 30℃). Adult females laid eggs during all days except from 00:00-02:00 (scotophase time). The ovipositional distribution rate was 26.1% from 20:00 to 22:00, which was the peak, and the next peak was 15.7% at 10:00 to 12:00. P. ricaniae showed arrhenotokous parthenogenesis in which unfertilized eggs develop into males. Therefore, the results suggest that P. ricaniae may be a biological control agent for R. sublimata.

• Korean journal of applied entomology
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• v.44 no.1 s.138
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• pp.43-50
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• 2005

Parasitism of the egg parasitoid, Trichogramma evanescens, to its main host insect, the Asian corn borer, Ostrinia furnacalis in Korea was compared with that of T. ostriniae that is the dominant species in China on the same host insect. Parasitoid adults of both species emerged more than 50 percent within 4 hours after lights-on in 16L/8D photo period regime and showed a circadian rhythm of emergence. The developmental period from oviposition to emergence in both parasitoids was ca. 11 days and there were no significant differences between the two species and between female and male of each species, either. Both species also showed superparasitism even when the parasitic rates in one egg mass were below 100 percent. Both species oviposited by 5 days after emergence, and maximum longevities of each female adult of both species were 8 day for T. evanescens and 6 day for T. ostriniae. The total number of eggs parasitized by T. evanescens was ca. 38 eggs and ca. 31 eggs by T. ostriniae. Newly emerged female parasitoid laid eggs on about $50\%$ of the host insect egg mass, and the parasitism decreased with the adult age of egg parasitoids in both species. The sex ratio of two species was female-biased about $80\%$.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.200-206
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• 1982

A computer simulation model was constructed to explore the phonology of the Striped Rice Borer, Chilo suppressalis (Walker), in Korea. The phenological system model based on the concept of distributed time delay was written in the computer program 'INSECT' and simulated with the estimated parameters of the effective day-degrees (DEL) and the order of time delay (K) for determining the validity of the system model. The accumulated emergence curves obtained from the phenological model were slightly different from the observed light trap data at the early and late stage of the moth emergence in 1978. The differences between observed and simulated $50\%$ emergence date were five to six days in the locations of Suweon and Chuncheon, while it was only two to three days in Iri, Daegu, Boseong, and Milyang. The phenological model should be further improved for simulation of field population changes by adding the information of the time delay process in each developmental stage, the age distribution of overwintered population, and the limiting factors of the borer mortality.

• 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.