• Korean journal of applied entomology
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• v.46 no.3
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• pp.357-362
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• 2007

Copris tripartitus Waterhouse is a coprophagus insect which enhances the soil fertility as conveying dung into the soil. We compared preimaginal development, mortality, and size of C. tripartitus at various temperature condition (15, 17.5, 20, 25, 27.5, 30). Total preimaginal periods ranged from 118.0d at $17.5^{\circ}C$ to 49.3d at $27.5^{\circ}C$. Development threshold temperature (DT) and total effective temperature for the development of egg, larva, pupa and for complete development (egg to emergence) were 12.1, 11.2, 12.1 and $9.2^{\circ}C$ and 82.7, 462.0, 225.7 and 947.2 degree days, respectively. The mortality of egg and larva was the lowest at $25^{\circ}C$. The optimum temperature for hatchability and on the development of C. tripartitus was estimated to the $25^{\circ}C$.

• Journal of Embryo Transfer
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• v.22 no.1
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• pp.53-61
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• 2007

This study was investigated factors affecting the pregnancy rates after transfer of pronuclear microinjected embryos for the production of transgenic Korean black goats. Embryo transfer was carried out in 343 recipient Korean black goats from September 1999 to June 2000. Estrus was induced by the insertion of intravaginal progesterone devices $CIDR^(R)$ for 2 weeks. A single injection of 400 IU equine chorionic gonadotropin was administered at 48h before $CIDR^(R)$ removal to increase the proportion of does cycling and ovulation rate. Good quality embryos were prepared by microinjection of DNA into the pronuclei of fertilized goat oocyte and cultured in vitro. Pronuclear microinjected $1{\sim}8$ cell stage embryos were surgically transferred into the oviducts of the recipient at day 4 or 5 following $CIDR^(R)$ removal, and morula to blastocyst stage embryos were surgically transferred into uterus at day 9. Pregnancy was diagnosed by transrectal ultrasound scanning at $20{\sim}30d$ and 8 weeks following embryo transfer. The pregnancy rate was affected by several factors, such as estrus induction, the number of previous transfer, transfer site, stage of CL (corpus luteum), the number of recipient CL, stage of embryos and the number of transferred embryo. The pregnancy rate was significantly higher in recipients that came into estrus naturally than recipients that induced to come into estrus with $CIDR^(R)$(59.1% vs. 36.8%; P<0.05). The pregnancy rate was higher when the embryos were transferred into the left oviduct than transferred into the right oviduct (42.9% vs. 35.3%; P<0.05). The pregnancy rate of recipients with $CH_1$ (early) stage corpus hemorrhagicum in ovary was hi틴or than recipient with $CH_3$ (late) stage hemorrhagicum (47.5% vs. 17.9%; P<0.01). Higher pregnancy rates were obtained by transfer of 1-cell stage embryos into oviduct while late blastocysts (51.6% vs. 66.7%; P<0.01) into uterus. The pregnancy rates when 3 embryos were transferred to recipients were significantly higher than when 2 embryos we.e transferred (47.6% vs. 27.0%; P<0.05). Although there were no significant difference among the group, adhesion of reproductive organs, uterine size, ovulation rate of recipients, presence of large follicle and difficulty of transfer affected pregnancy rate of recipient. Higher pregnancy rates were obtained in the recipients with $8{\sim}15m$ diameter uterine horn as compared to the recipients with <5m diameter or >20mm diameter uterine hem (38.9%, 20% vs. 18.2%), in the recipients with large follicle in the ovulated ovary ipsilaterally (53.6% vs. 37.1%) and in the transfer which was carried out easily (39.2% vs. 27.8%, 0%). In conclusion, the high rate of pregnancy was achieved following transfer of pronuclear microinjected embryos when three or four 1-cell stage embryos were transferred into oviduct with $CH_1$ stage corpus hemorrhagicum in the ovary of recipient which came into estrus naturally.

• Korean journal of applied entomology
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• v.34 no.1
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• pp.65-69
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• 1995

This study was carried out to investigate the development and fecundity of Liriomyze chinensis under different temperatures. Egg periods were 4.5, 2.9 and 1.9 days, larval periods 12.7, 5.8, 4.5, days, pupal periods 20.1, 16.3 and 13.0 days, and total development periods from egg to adult emergence were 32.5, 25.0 and 19.4 days under 20, 25, $30^{\circ}C$ of constant temperatures, respectively. Based on this results, developmental threshold temperatures were calculated as 13.0, 11.0 and $7.2^{\circ}C$ and total effective temperatures as 33.0, 86.1 and 293.6 degree-days for egg, larva and pupa, respectively. seventy-eight% of the tested files emerged within four hours and a half after lighting, and none was emerged after eight hours and a half. The longevities of male and female were 5.0 and 8.5 days and the female fly laid 165.8 eggs with her life and punctured 983.8 stipples at $25^{\circ}C$.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.271-278
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• 1999

This study was conducted to investigate the cytogenetic properties, in vitro development, and their relationship in the bovine reconstituted embryos following cell cycle-controlled nuclear transfer. Sixteen-cell stage embryos were treated by nocodazole, and after release from nocodazole treatment, their blastomeres were separated and allowed to subsequent cleavage. Blastomeres within 1.5 h post cleavage(hpc) and at 3hpc were transferred to enucleated oocytes at MII-phase or S-phase. Donor nuclei transferred into M II-phase recipients underwent various nuclear remodeling, such as extrusion of a polar body(PB)-like structure, premature chromosome condensation(PCC) and chromatin modifications. These nuclear remodeling patterns varied by the time post cleavage of donor blastomeres. Developmental rate to the blastocyst stage differed with time post cleavage of donor blastomeres and existence of a PB-like structure. Whereas do-nor nuclei transferred into S-phase oocytes did not undergo PCC and other major modifications, and their developmental potentials less depended on the nuclei types. This result confirms that the nuclear remodeling type differs with donor and recipient cell cycle stage, which affect the development of reconstituted bovine embryos.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.268-269
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• 2000

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.251-261
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• 1994

This study was conducted to get some basic information about rice plant development rate and heading ecology in various climatic conditions, growing nine varieties at three locations, Jinbu as the mountainous cool area, Suweon and Iri as the plain area for two years from 1987 to 1988. Average daily air temperature and day length from transplanting to heading date were analyzed in relation to the heading. Heading date and development rate of each variety were estimated by the Symplex method and the fitness of the model was evaluated. The results obtained as follows: Average daily air temperatures among varieties during the period from transplanting to heading ranged from 18 to $19^{\circ}C$ in Jinbu, from 22.5 to $23.5^{\circ}C$ in Suweon, and from 23.5 to $24.5^{\circ}C$ in Iri, the late-maturing varieties requiring the higher temperatures. The average heading days were about 20 days longer in Jinbu and $3{\sim}5$ days shorter in Iri than those in Suweon in all varieties. Little differences in accumulated temperature from transplanting to heading were observed in regions and years, and also among varieties. Developmental stages could be expressed as the accumulation of daily development rate and the predicted heading dates by the Symplex method were similar to the observed ones. The development rate of each variety varies with air temperatures. The early maturing Japonica types including the Unbong variety were fast in development rate at lower temperatures, but the late-maturing varieties of the Japonica type were late. A model to predict the heading dates of rice varieties by the Symplex method using air temperatures and day lengths was feasible.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.373-378
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• 2011

The striped fruit fly, Bactrocera scutellata, damages pumpkin and other cucurbitaceous plants. The developmental period of each stage was measured at seven constant temperatures (15, 18, 21, 24, 27, 30, and $33{\pm}1.0^{\circ}C$). The developmental time of eggs ranged from 4.2 days at $15^{\circ}C$ to 0.9 days at $33^{\circ}C$. The developmental period of larvae was 4.2 days at $15^{\circ}C$, and slowed in temperatures above $27^{\circ}C$. The developmental period of pupa was 21.5 days at $15^{\circ}C$ and 7.6 days at $33^{\circ}C$. The mortality of eggs was 17.1% at $15^{\circ}C$ and 22.9% at $33^{\circ}C$, Larval mortalities (1st, 2nd, 3rd) were 24.1, 27.3 and 18.2%, respectively, at $15^{\circ}C$, Pupal mortalities were 18.2% at $15^{\circ}C$ and 23.1% at $33^{\circ}C$. The relationship between developmental rate and temperature fit both a linear model and a nonlinear model. The lower threshold temperatures of eggs, larvae, and pupae were 12.5, 10.7, and $6.3^{\circ}C$, respectively, and threshold temperature of the total immature period was $8.5^{\circ}C$. The thermal constants required to complete the egg, larval, and pupal stages were 33.2, 118.3, and 181.2 DD, respectively. The distribution of each development stages was described by a 3-parameter Weibull function.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.74-84
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• 2001

The early developmental stages, growth and morphological changes of the Korean bullhead, Pseudobagrus fulvidraco, were studied from a series of reared specimens. Details of the early developmental stages are illustrated with special reference to morphological transformations. Egg and sperm of Korean bullhead were obtained from mature adults under hormonal treatment, fertilized artificially, and incubated in the aquarium. The incubation period of fertilized eggs was 55 to 66 hours at a temperature of 24.9${\pm}$0.34$^{\circ}$. Larvae were fed successively with Artemia salina and Daphnia magna for 2 to 15 days and artificial food after 20 days. Fertilized eggs were adhesive and spherical with a diameter of 2.04mm(n = 100). The mean total length of newly hatched larvae was about 4.92${\pm}$0.33 mm. Mouth opening occurred on one-day-old yolk-sac larvae, and initial feeding was observed on the third day after hatching. The morphological transitions from larvae to juvenile and juvenile to young stages occurred when the fish reached about 17 mm in total length (about 13days after hatching) and about 32 mm in total length (about 30 days after hatching), respectively. Many changes in proportion of body parts to total length were observed at about 7~8 mm and 30~32 mm, corresponding to the transformations from larvae to juvenile and from juvenile to young, respectively. In comparing relative growth of each body part against total length, those characteristics related to head parts showed positive growth in the pre-larval stages, while those concerning mobile abilities showed positive growth in the post-larval stage.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.295-301
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• 2015

We investigated mycophagous ladybird, Illeis koebelei from 12 species of plants infected with powdery mildew in Gyeonggi-do, Korea. The pear tree, Pyrus ussuriensis var. macrostipes (Nakai), was most preferred by I. koebelei. This species was found from early July to early November in pear orchards. There was no entomophagous trace in the gut of I. koebelei without powdery mildew spores in a microscope. All stages except egg and pupa are obligate mycophagous, and the feeding potential is ranked as follows: fourth instar, adults, third instar, second instar, and first instar. Feeding amounts of each stage of I. koebelei were 45.6, 144.4, 372.2, 628.1, and $473.7mm^2$ of cucumber powdery mildew per day. Fourth instar larvae showed highest consumption of cucumber powdery mildew. Developmental periods of four larval instars and adults feeding cucumber powdery mildew were 1.2, 2.3, 2.3, 4.6, and 37.7 days, respectively, at $25^{\circ}C$. In this study, we could not determine the feeding potential of I. koebelei against the cucumber powdery mildew; therefore, and further studies are required to elucidate the potential of this species as a biological control agent, e.g., mass rearing, selection of low toxic chemical agents for Integrated Pest Management (IPM), and control techniques against powdery mildew in agro-ecosystems.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.179-185
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• 1998

The effect of physiological factors of beet armyworm, Spodoptera exigua (Hubner), on esterase variation was analyzed by comparing electrophoretic esterase isozymes. Each esterase isozyme was also characterized by substrate and inhibitor specificities. A total of 28 esterase isozymes were separated on 10% nondenaturing polycarylamide gel electrophoresis (PAGE). These isozymes were denoted from El to E28 according to cathodal migration distances. There was a variation in esterase isozymes among developmental stages. Larvae and pupae had more isozymes than did adults. Eggs had only eight isozymes. The isozymes of El and E2 were specific only in the first instar larvae. Esterases also showed variation according to different tissues. More kinds of esterase isozymes were found in epidermis and gut tissues than in hemolymph and fat body. Some isozymes were specific in epidermis (from El to E6), gut (E10, El 1, E25, E26, and E27), and hemolymph (E18). Among 10 naphthyl esters, a-naphthyl propionate was the most reactive substrate to the esterase isozymes. The isozymes were classified into cholinesterases (El0 and E24), arylesterases (E4, E9, E17, E19, E21, and E23), and carboxylesterases (the others) on the basis of inhibition by the esterase inhibitors-eserine, dichlorovos, moncrotophos, and paraoxon.