• Korean journal of applied entomology
• /
• v.5_6
• /
• pp.33-38
• /
• 1968

쌀바구미의 유충을 3기로 구분하여 각종 농도의 Apholate를 처리하여 그의 치사율$\cdot$발육속도$\cdot$산란수$\cdot$불임률 및 그의 지속성 여부를 조사하여 다음과 같은 결과를 얻었다. (1) 당대 치사율은 농도가 높아짐에 따라 높아 켰으며, 유령기 처리시의 치사율은 노령기 처리시보다 높았다. (2) 차대 치사율은 처리된 성에 따라 차가 있었고 전체적으로 자충 처리시가 자충 처리시보다 높아 치사돌연변이 유기율이 웅충 처리시에 높아짐을 알 수 있었다. (3) $0.5\%$ 이상의 처리구에서는 우화 성충 중에 각종 기형이 출현하였으며, 그 수는 농도가 높아짐에 따라 컸다. (4) 산란수의 감소는 자충 처리시가 웅충 처리시보다 심하였으며, 이것은 Apholate의 난자형성에 미치는 직접적인 영향이라고 생각된다. (5) 발육속도는 노령기 처리시가 유령기 처리시보다 늦어지며, 그 효과는 농도의 증가에 따라 높아진다. 차대의 생육기간은 자충 처리시가 웅충 처리시보다 길어졌다. (6) 화학적 불임제는 당대의 영향뿐 아니라 차대에도 그 영향력이 지속된다.

• Korean journal of applied entomology
• /
• v.52 no.1
• /
• pp.5-12
• /
• 2013

The Hawaiian beet webworm (Spoladea recurvalis) is one of the serious insect pests found on red beet (Beta vulgaris var. conditiva) in Korea. The study was conducted to investigate the development period of S. recurvalis at various constant temperatures, 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 32.5 and $35.0^{\circ}C$, with $65{\pm}5%$ RH and a photoperiod of 16L:8D. The developmental period from egg to pre-adult was 51.0 days at $17.5^{\circ}C$ and 14.6 days at $35.0^{\circ}C$. The developmental period of S. recurvalis was decreased with increasing temperature. The relationship between the developmental rate and temperature was fitted well by linear regression analysis ($R^2{\geq}0.87$). The lower developmental threshold and effective accumulative temperature of the total immature stage were $10.4^{\circ}C$ and 384.7 degree days, respectively. The nonlinear relationship between the temperature and developmental rate was well described by the Lactin model. The relationship between the cumulative frequency and normalized distributions of the developmental period for each life stage were fitted to the Weibull function with $R^2=0.63{\sim}0.87$.

• Reproductive and Developmental Biology
• /
• v.29 no.3
• /
• pp.169-174
• /
• 2005

This study was comducted to examine the effects of culture medium, and the osmolarity and osmotic change of the culture medium on in vitro maturation of porcine oocytes and developement of porcine parthenogenetic embryos. In Experiment 1, cumulus-oocyte complexes were matured in NCSU-23, mWM and mKRB, respectively, There was no difference in maturation rate($62.1\~71.3\%$) among groups. In Experiment 2, matured oocytes in each medium were activated and cultured for 6 days in the same media. Blastocyst formation rate was higher in NCSU-23($22.9\%$) than those of others($0\~0.6\%$, P<0.05). In Experiment 3, parthenogenetic embryos were cultured for 6 days in NCSU-23 with different osmolarity(300, 280 and 256 mOsmols) adjusted by NaCl. There were no differences in development rates to the blastocyst stage($11.0\~14.4\%$) among groups. In Experiment 4, activated oocytes were cultured for 2 days in NCSU-23 with 300, 280 and 256 mOsmols and then transferred to increased or decreased osmotic condition. Blastocyst formation rate was higher in a group which was transferred from the higher osmotic condition to the lowe. osmotic condition($21.0\%$) than a contrary group( $11.8\%$, (P<0.05). This result shows that the culture medium and the osmolarity of the culture medium affect the development of porcine parthenogenetic embryos, and the change of osmolarity from the higher condition to the lower condition at a certain developmental stage can enhance the development of porcine parthenogenetic embryos.

• Korean journal of applied entomology
• /
• v.50 no.3
• /
• pp.235-245
• /
• 2011

Temperature-related parameters of Panonychus citri (McGregor) (Acarina: Tetranychidae) development were estimated and a stage-structured matrix model was developed. The lower threshold temperatures were estimated as $8.4^{\circ}C$ for eggs, $9.9^{\circ}C$ for larvae, $9.2^{\circ}C$ for protonymphs, and $10.9^{\circ}C$ for deutonymphs. Thermal constants were 113.6, 29.1, 29.8, and 33.4 degree days for eggs, larvae, protonymphs, and deutonymphs, respectively. Non-linear development models were established for each stage of P. citri. In addition, temperature-dependent total fecundity, age-specific oviposition rate, and age-specific survival rate models were developed for the construction of an oviposition model. P. citri age was categorized into five stages to construct a matrix model: eggs, larvae, protonymphs, deutonymphs and adults. For the elements in the projection matrix, transition probabilities from an age class to the next age class or the probabilities of remaining in an age class were obtained from development rate function of each stage (age classes). Also, the fecundity coefficients of adult population were expressed as the products of adult longevity completion rate (1/longevity) by temperature-dependent total fecundity. To evaluate the predictability of the matrix model, model outputs were compared with actual field data in a cool early season and hot mid to late season in 2004. The model outputs closely matched the actual field patterns within 30 d after the model was run in both the early and mid to late seasons. Therefore, the developed matrix model can be used to estimate the population density of P. citri for a period of 30 d in citrus orchards.

• Korean journal of applied entomology
• /
• v.39 no.2
• /
• pp.117-122
• /
• 2000

The chemosterilizing effects of 4 benzoylphenylureas (BPUs), were tested on the adult house fly at different developmental stages. The male and female flies before insemination (I-day-old) or with fully developed ovaries (5-day-old) were exposed to the flask surface coated with BPUs solution (300 ppm) for 24 hrs. None of the eggs layed by the 5-day-old flies on the next day of exposure to either flufenoxuron or teflubenzuron hatched to larvae. The eggs layed by the 5-day-old flies exposed to either triflumuron or diflubenzuron also showed a significantly reduced hatchability of 23%. The first egg batches layed by 1-day-old flies exposed to flufenoxuron showed hatchability of only 1%. These results indicate that the BPUs applied were effective in egg sterilization irrespective of developmental stage of house fly. The effect of flufenoxuron was the most pronounced and lasted for 5 days after exposure.

• Korean journal of applied entomology
• /
• v.51 no.4
• /
• pp.431-438
• /
• 2012

The developmental time of the nymphs of Myzus persicae was studied in the laboratory (six constant temperatures from 15 to $30^{\circ}C$ with 50~60% RH, and a photoperiod of 14L:10D) and in a green-pepper plastic house. Mortality of M. persicae in laboratory was high in the first(6.7~13.3%) and second instar nymphs(6.7%) at low temperatures and high in the third (17.8%) and fourth instar nymphs(17.8%) at high temperatures. Mortality was 66.7% at $33^{\circ}C$ in laboratory and $26.7^{\circ}C$ in plastic house. The total developmental time was the longest at $14.6^{\circ}C$ (14.4 days) and shortest at $26.7^{\circ}C$ (6.0 days) in plastic house. The lower threshold temperature of the total nymphal stage was $3.0^{\circ}C$ in laboratory. The thermal constant required for nymphal stage was 111.1DD. The relationship between developmental rate and temperature was fitted nonlinear model by Logan-6 which has the lowest value on Akaike information criterion (AIC) and Bayesian information criterion (BIC). The distribution of completion of each developmental stage was well described by the 3-parameter Weibull function ($r^2=0.95{\sim}0.97$). This model accurately described the predicted and observed occurrences. Thus the model is considered to be good for use in predicting the optimal spray time for Myzus persicae.

• Korean journal of applied entomology
• /
• v.49 no.3
• /
• pp.199-204
• /
• 2010

The seasonal fluctuation of the large 28-spotted lady beetle, Henosepilachna vigintioctomaculata (Motschulsky), was observed in potato fields of Gangneung region, Gangwondo Province. The effects of their leaf consumption over a 24 hour period and developmental periods by different temperatures were investigated, and then the developmental threshold (DT) and effective cumulative temperature (ET) of each stage were calculated. Various developmental stages of H. vigintioctomaculata were captured in the fields from May to September, with three peaks in late May, late June, and late August. Leaf consumption by larval stages increased with the development of instar. The 4th instar larvae consumed potato leaves much more than other stages. Egg hatchability and emergence rate of H. vigintioctomaculata were lower at $10^{\circ}C$ and $30^{\circ}C$, but higher at around $20{\sim}23^{\circ}C$. The developmental periods of each stage became shorter as temperature increased; 90 days at $10^{\circ}C$, 40 days at $20^{\circ}C$ and 25 days at $25^{\circ}C$. Base on developmental velocity to temperature, calculated DT and ET were $7.3^{\circ}C$ and 83.

• Korean journal of applied entomology
• /
• v.41 no.3
• /
• pp.199-204
• /
• 2002

Population fluctuation of O. kashmirica benefica, a major natural enemy of citrus red mite (Panonychus citri), was surveyed from 1997 to 2000 in yuzu orchards in Goheung region and, developmental periods, developmental threshold temperature (DT) and effective cumulative temperature (ET) were estimated. Under four constant temperatures of 15, 20, 25 and 30$\^{C}$, developmental periods from egg to adult of the beetles were 67.3, 31.4, 19.4 and 15.3 days, respectively. The period of each stage was long in the order of pupa> egg > 3rd larva> 2nd larva> 1st larva. Mean numbers of eggs oviposited by a female per day were 3.3, 5.6, 7.3 and 7.7 under the temperatures, respectively. The highest hatchability (92%) and adult emergence (60%) were shown under 25$\^{C}$. Adult longevity was 54.3 days for females, and 58.6 days for males. In natural condition, the sex ratio of the beetle was 0.58. Developmental thresholds (DT) for egg, 1st, 2nd, 3rd larva, pupa, and egg to adult were 12.7, 10.0, 10.8, 7.9, 10.1 and 10.6$\^{C}$, respectively. The effective cumulative temperatures (ET) were 41.4, 22.9, 22.7, 46.6, 165.3, 292.9 day-degree at the same development stage, respectively. The beetle occurred from early April to early December in yuzu orchards. The population peak of the beetles was dependent on the amount of prey mite (Panonychus citri), and the ratio of the predator to prey mite was 1 to 100-200 at predator peak stage in the field.

• Korean journal of applied entomology
• /
• v.53 no.3
• /
• pp.287-293
• /
• 2014

Matsumuraeses phaseoli is one of the main pests that attack the flowers and pods of red bean (Vigna angularis) and mungbean (Vigna radiata) in Korea. To elucidate the developmental characteristics and over-wintering stage of M. phaseoli, several stages of the insect were observed through artificial rearing under outdoor conditions in Suwon ($37^{\circ}$16'N $126^{\circ}$59'E 35ASL), Korea. In colonies in which neonate larvae were reared at about 2-week intervals for more than a year, the developmental period from larva to adult emergence became longer from spring to summer, but shorter from summer to autumn; aestivation was not observed during the summer season. The colony in which rearing started on Oct 8, 2008 over-wintered as pupae and emerged in late April next year with a survival rate of 6%. However, the colony in which the rearing started on Oct 23, 2008 over-wintered as mature larvae, pupated in late April, and emerged in early and mid-May with a survival rate of 2%. When the fifth instar larvae were transferred outside from the laboratory ($25^{\circ}C$, 15L:9D) between November and February, no larvae could survive during the winter season. Some newly laid eggs and newly emerged adults could not hatch and could not survive, respectively, in outdoor conditions in November and December. These results suggest that neonate larvae of M. phaseoli that hatch in October can over-winter as late larvae or pupae in Suwon, Korea.

• Reproductive and Developmental Biology
• /
• v.28 no.1
• /
• pp.1-6
• /
• 2004

This study was conducted to investigate the effects of donor cell type, individual, passage number and trypsinization time on the in vitro development of bovine somatic cell nuclear transfer embryos. Three cell types (skin, muscle and cumulus cells) and cells from 3 individuals were used for nuclear transfer. Cell were passaged by 5, 15 or 30 times, and cell were trypsinized for 1 or 3 min before injection. Nuclear transfer were performed by conventional fusion method. Development rates to the blastocyst stage were not significantly different among three cell types (16.5∼23.9%) and individuals (16.4∼19.5%). Blastocyst formation rate of cloned embryos reconstituted with cells at passage 30 (5.8%) was significantly lower than those of embryos reconstituted with 5- and 15-passaged cells (25.3 and 23.5%, respectively, P＜0.05). The rate of embryos developed to the blastocyst stage was higher in embryos reconstituted with cells trypsinized for 1 min (30.7%) compared to embryos reconstituted with cells trypsinized for 3 min (P＜0.05). The result of the present study indicates that different donor cell types and individuals used in this study did not affect the development of cloned bovine embryos. However, passage number and trypsinization time of donor cells affect the in vitro development of cloned bovine embryos.