• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.285-296
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• 2010

This study was implemented among 100 students of C College of Public Health who have healthy permanent dentition in order to measure the morphology and sizes of clinical crowns of permanent maxillary molars. The following are conclusions of this study. 1. The cusp height, crown width, crown thickness of clinical crowns appeared to be bilaterally symmetrical. 2. The strong development of the buccal groove showed to be superior in the right first molar. The appearance rate of the buccal pit was high in the right first molar also. 3. The type 4th cusp appeared as 100% in the left and right first molars, and 78%, 75% in the left and right second molars respectively. 4. The distal lingual cusp(DLC) size were bilaterally symmetrical in the type 4th cusp. 5. As for the distance between two cusp tips, it was large between mesial cusp tips in all of the first and second molars at both sides. 6. Development of the Carabelli's cusp was high in both the left and right first molars. 7. The appearance rate of the oblique ridge was 87.0% in the right first molar, 73.0% in the right second molar, 88.0% in the left first molar, and 73.0% in the left second molar. This is considered to be caused by people who have mild dental crown caries in their first molars. 8. The appearance rate of the mesial marginal ridge tubercle(DMRT) was high in both of the left and right first molars. That of the distal tubercle was 16.0% in the right first molar, 26.0% in the right second molar, 14.0% in the left first molar, and 21% in the left second molar.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.249-255
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• 2008

The comparative toxicity of recommended rates of three acaricides, fluacrypyrim, cyflumetofen and spiromesifen to the predatory mite, Neoseiulus womersleyi and its prey, Tetranychus urticae was bioassayed in the laboratory. Fluacrypyrim and cyflumetofen were much less toxic to adult females of N. womersleyi than to those of T. urticae. Adult female predators treated with these two acaricides produced $88{\sim}93%$ as many eggs as did control females. Fluacrypyrim and cyflumetofen did not affect the hatch of N. womersleyi eggs or the development of surviving immature predators, and $92{\sim}96%$ of immature predators reached adulthood. Spiromesifen at its treated concentration did not significantly affect the survival and reproduction of adult female predators but caused 100% mortality in larvae of N. womersleyi. Adult female predators survived on a diet of spider mites treated with fluacrypyrim and cyflumetofen, and their fecundity was not significantly affected. Moreover, immature predators developed normally on prey treated with these two acaricides. The results indicate that fluacrypyrim and cyflumetofen are promising candidates for use in integrated mite management programs where N womersleyi is the major natural enemy.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.31-36
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• 2008

The embryonic and postembryonic developments of Nezara antennata Scott were observed in 5 different rearing cages such as A (Cylindrical, ${\phi}\;10cm{\times}4cm$), B (Cylindrical, ${\phi}\;14.5cm{\times}2.8cm$), C (Rectangle, $6.5L{\times}6.5cmW{\times}10cmH$), D (Cylindrical, ${\phi}$ 9cm in bottom & ${\phi}$ 11.5 cm in $upper{\times}10.8cm$) and E (Cylindrical, ${\phi}\;15cm{\times}7.5cm$) containing soybean and peanut seeds as food, and sponge soaked with water under laboratory condition of $24^{\circ}C$ and 15L : 9D. Hatchability ranged from 93 to 97%. Nymphal duration was shortest of 6 days in the 1st instar and longest of 10 days in the 5th instar. The nymphal duration was 38 to 39 days observed in the rearing cages. Emergence rate was in the range from 53 to 62% with highest in A and B cages. Adult longevity was 65 to 75 days for male, and 67 to 74 days for female, and was longest in the B cage. Total number of eggs laid by female adult was in the range from 51 to 56 without significant difference in the rearing cages, and was the most in the B cage. Accordingly, the reproductive rate of N. antennata for 1 generation was within 25 to 33 times, and was highest in the B rearing cage. Therefore, it could be concluded that B cage is most suitable for stable rearing of N. antennata under laboratory condition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.126-133
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• 1988

To know the optimum harvest time for seed yield and seed quality a local variety of rye 'Paldang-homil'was harvested at seven different harvest times from 25 to 55 day after heading (DAH) at five-day intervals in 1984 ani 1986. Seed development, seed germination and seedling growth were observed. The l000-grain weight increased as harvest time delayed until 50 DAH in both years. Although grain yield tended to increase with delay of harvest time, the yield differences between succeding harvest time was highest between 40 DAH and 45 DAH. Germination rate of seeds harvested before 30 DAH were lower than those after 35 DAH at 20 C, but at 10 and 30 C before 35 DAH were lower after 40 DAH. Plant height and dry weight of seedlings increased with delay of harvest time up to 45 DAH in pot. Heading stages were similar among the seeds harvested 40-55 DAH. Culm length was not different among the harvest times. The optimum harvest time for seed production of rye seems to be 45 DAH (38 days after flowering).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.608-618
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• 1996

Wild perennial types of genus Glycine, as sources of genetic diversity, have been recently employed in the soybean breeding programs. This study was carried out to introduce some useful characters of wild perennial Glycine tomentella into common cultivars, G. max. Parent materials used for interspecific hybridization were three common cultivars, Ulsankong, Baemkong and Danyeobkong, and four G. tomentella strains having different diploid(2n) of 38, 40, 78, and 80. Their cross-fertility, effect of reciprocal cross, development comparison of crossing pod and optimum timing to efficient crossing were investigated. Plant were grown in 1/2,000 Wagner pots in greenhouse and field. Crossing efficiency and pod survival rate were the highest in 2n=38 of the four G. tomentella strains when the common cultivars were fixed as female parents. In the reciprocal cross of three common cultivars and four G. tomentella strains, when the former was used as maternal sources, they showed better crossing rate and longer pod survival than the latter. In the interspecific hybridization between G. max cv. Baemkong andG. tomentella, 2n=38, the pod formed from the female G. tomentella had relatively greater size and weight than that from the female Baemkong in comparison with parents. However, the reverse result was true in a number of ovules per pod. More efficient interspecific hybridization in the field was made on August 20, when temperature and relative humidity were higher and day length was shorter, than one or two months earlier.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.242-246
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• 2006

This study was showed into the pollen development with in vivo by bud size and genotype. Microspores of buds from 2.0 mm to 2.5 mm of all genotypes were composed of mainly tetrad cells and early uninucleate stage cells. Microspores derived from buds of 2.5-3.0 mm were exposed cells of early uninucleate, middle uninucleate, and late uninucleate. Microspores from buds of 3.0-3.5 mm contained mostly late uninucleate stage cells and showed some early binucleate stage cells. Microspores of buds with 3.5-4.0 mm in length were composed of mainly binucleate stage cells and decreased late uninucleate stage cells. Microspore with more than 4.0 mm were entered into binucleate stage cells of divided generative nucleus and vegetative nucleus. In 'Tamlayuchae', microspores derived from buds of 3.5-4.0 mm were observed cells of late uninucleate stage and early binucleate stage because of late microspore development. In MS-maintainer, the spring type, microspore derived from buds of 2.5-3.0 mm were observed tetrad stage cells.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.179-188
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• 2009

Nymphal development of the B and Q biotypes of Bemisia tabaci was normal on all seven tomato varieties tested. However, their nymphal development was different on red pepper varieties. B biotype was not normally developed on nine red pepper varieties tested. On the contrary, Q biotype was normally developed, but its adult emergence rate was very low in Nokkwang variety than in other eight varieties. The EPG analysis of the feeding behavior of Bemisia tabaci showed that B and Q biotypes had different duration of phloem phases on red pepper. Q biotype showed longer phloem phases than B biotype. On Nokkwang variety, Q biotype had short phloem phases and did not prefer to feed on Nokkwang variety. Interestingly, Q biotype was found to have long duration of phloem phases on eight red pepper varieties, but B biotype did not prefer to feed on red pepper varieties. However, both biotypes did not show any difference in feeding time on tomato varieties.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.195-200
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• 2006

This study was carried out to clarify the biologies and morphological characteristics of Rhynchaenus sanguinipes. Also some chemicals were tested to screen the effective insecticide for the control of the species. Up to date, Zelkova serrata has been hewn as host plant of Rhynchaenus sanguinipes, which shows serious damage in this country. In the present study, Ulmus pumila was first found as host plant in this study. Body lengths of larvae, pupa and adult were 4.53$\pm$0.30 mm, 3.30$\pm$0.42 mm and 2.96$\pm$0.12 mm, respectively. The overwintered adult of the species emerged on early April to late April, and adult of nekt generation emerged on early May to late May, Pupal periods were 10, 7.2, 5.1 and 4 days on 16, 20, 24 and 28$^{\circ}C$, respectively. The lower developmental threshold temperature was 5.8$^{\circ}C$. Four braconid parasitoids were found as natural enemies, which emerged mainly on late April to early June. Insecticidal activities with treatments of fenitrothion 50% EC, indoxacarb 30% WG, ethofenprox 20% EC and thiacloprid 10% SC was investigated against adult of R. sanguinpes, and they showed >90% mortality.

• 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.50 no.4
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• pp.335-342
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• 2011

The effects of gamma irradiation on the survival, development, fecundity, and sex ratio of the multicolored Asian ladybird beetle (Harmonia axyridis) were investigated. A dose of more than 50 Gy dose of irradiation on eggs completely inhibited hatch, and 1st and 3rd instar larva irradiated with over 40 Gy almost died. Adverse effects of gamma irradiation over 70 Gy were also observed in the survival and development of pupae and adults. Although irradiated individuals usually survived, they had longer periods of larval and pupal development than untreated individuals. Slight female-biased sex ratios were observed in some treatments. However, sex ratio differences soon equilibrated. Generally, inherited harmful effects of gamma irradiation were observed in F1 and F2 generations. Comet tail indicating DNA damage was showed in survival individuals exposed to gamma irradiation.