• Korean journal of applied entomology
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• v.31 no.4
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• pp.480-485
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• 1992

Laboratory studies were done to evaluate the effects of diflubenzuron on embryonic and postembryonic development of Riptortus clavatus Thunberg. Diflubenzuron prevented egg hatch; younger eggs(O-12 h old) were 2 times as susceptible as older(48-60 h old) eggs, but embryos of both younger and older eggs developed normally. Susceptibility of nymphs to diflubenzuron decreased with each successive molt. Compared with the first instar, relative tolerance to diflubenzuron was 1.5 times for the second instar, 18.2 times for the third instar, 39. 4 times for the fourth ins tar and 42.4 times for the fifth instar. Even as low concentrations, diflubenzuron prevented significant numbers of third instar nymphs from developing to fourth and fifth instar nymphs or adults. Weight, longevity and fecundity of adults surviving treatment in the final (fifth) instar were also adversely affected.

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.43-48
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• 2007

This study was conducted to examine the characteristics of fresh and frozen semen, proliferating efficiency by AI, and the coat color of offsprings in Korean Native Striped Cattle (Bos namadicus Falconer, Chikso). Semen were collected from 6 heads of tiger-coated male Chikso. In vitro fertilization (IVF) was conducted with frozen-thawed semen and in vitro matured Korean native brown cattle (general Hanwoo) oocytes. Total 18 heads of Hanwoo and Chikso were inseminated using Chikso semen. Coat colors of total 40 offsprings produced by AI were evaluated. The characteristics of the fresh and frozen-thawed Chikso semen did not differ among individuals. In vitro fertilization rate of Chikso semen was not different from that of general Hanwoo semen. However, developmental rate to the blastocyst stage of IVF embryos was higher in Chikso semen (25.9%) than in general Hanwoo semen (p<0.05). There was no difference in conception rate after AI between Chikso and general Hanwoo. The coat colors of offsprings varied, only 42.5% (17/40 heads) of offsprings had tiger coat color. Futhermore, only 55% of offsprings produced from the tiger-coated recipients had tiger coat color. This result shows that proliferation of Chikso by AI is possible, but further research approaches may be needed to enhance the productivity of tiger-coated Chikso.

• Korean journal of applied entomology
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• v.30 no.2
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• pp.103-137
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• 1991

The developmental period(mean $\pm$ SE) of the red flour beetle, Tribolium castaneum was studied on brown rice at four constant temperature(25, 28, 34, $36^{\circ}C$ $\pm$ $0.5^{\circ}C$, RH 70%)conditions. Based on the results, the lower and the upper developmental threshold temperature for the beetle were also estimated. The duration of the egg stage was estimated to be 7.6 $\pm$ 0.25, 4.8 $\pm$ 0.10, 3.0 $\pm$ 0.03 and 2.5 $\pm$ 0.09 days at 25, 28, 34, $36^{\circ}C$, respectively. That of the larval stage was estimated to be 53.3 $\pm$ 1.49, 33.4 $\pm$ 0.57, 30.6 $\pm$ 0.70, 31.0 $\pm$ 1.18; that of the pupal stage to be 12.1 $\pm$ 0.17, 7.8 $\pm$ 0.09, 5.7 $\pm$ 0.09, 5.0 $\pm$ 0.07 ; that of the overall period which spans from eggs to the adult emergence to be 72.3 $\pm$ 1.67, 46.0 $\pm$ 0.55, 39.4 $\pm$ 0.64, 38.7 $\pm$ 1.15 days at 25, 28, 34, $36^{\circ}C$, respectively. The duration of the egg and the pupal stage were similar to those of the results reared on other diets such as wheat and maize. Fed on brown rice, however, the duration of the larval stage was significantly retarded than on wheat. The mortality of the beetle during ,development was higher on brown rice than on wheat reported, indicating that brown rice is a poor diet compared with wheat. The lower developmental threshold temperature was estimated to be $20.0^{\circ}C$ for all stages of the beetle. The upper one was estimated to be $40.2^{\circ}C$ for the overall stage. The modal value of the moulting times during the larval stage was 7. However, as temperature increased,.the frequency of the beetle that moulted more than 7 times became higher. The sex ratio of the beetle was not affected by temperature.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.261-269
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• 2018

The cowpea aphid Aphis craccivora Koch (Hemiptera: Aphididae) is a polyphagous species with a worldwide distribution. We investigated the temperature effects on development periods of nymphs, and the longevity and fecundity of apterous female of A. craccivora. The study was conducted at six constant temperatures of 10.0, 15.0, 20.0, 25, 30.0, and $32.5^{\circ}C$. A. craccivora developed successfully from nymph to adult stage at all temperatures subjected. The developmental rate of A. craccivora increased as temperature increased. The lower developmental threshold (LT) and thermal constant (K) of A. craccivora nymph stage were estimated by linear regression as $5.3^{\circ}C$ and 128.4 degree-days (DD), respectively. Lower and higher threshold temperatures (TL, TH and TH-TL, respectively) were calculated by the Sharpe_Schoolfield_Ikemoto (SSI) model as $17.0^{\circ}C$, $34.6^{\circ}C$ and $17.5^{\circ}C$. Developmental completion of nymph stages was described using a three-parameter Weibull function. Life table parameters were estimated. The intrinsic rate of increase was highest at $25^{\circ}C$, while the net reproductive rate was highest at $20^{\circ}C$. Biological characteristics of A. craccivora populations from different geographic areas were discussed.

• Korean journal of applied entomology
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• v.42 no.3
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• pp.217-223
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• 2003

Effects of temperature on the development and reproduction of the Luciola lateralis were investigated at various temperatures. The development time of eggs, larvae, and pupae were shorter at higher temperatures than at lower ones. The insect did not develop at 10$^{\circ}C$ and 35$^{\circ}C$. The hatchability was 61.5% at 15$^{\circ}C$, 73.9% at 20$^{\circ}C$, 93.3% at 23$^{\circ}C$, 91.8% at 25$^{\circ}C$, 74.0% at 27$^{\circ}C$, and 46.0% at 30$^{\circ}C$, indicating the best hatchability rate at the temperature condition of 23 DC. Larval periods were 341.5:t 23.2 days at 15$^{\circ}C$, 265.5${\pm}$17.5 days at 20$^{\circ}C$, and 250.9${\pm}$11.7 days at 25$^{\circ}C$. Pupal periods were 94.7${\pm}$11.5 days at 15$^{\circ}C$, 41.7${\pm}$9.1 days at 20$^{\circ}C$, and 18.5${\pm}$7A days at 25$^{\circ}C$. Emergence rate was 23.3, 89.3 and 80.7%, respectively at the above temperatures. Adult longevity of female was 18.0 days at 15$^{\circ}C$, 2004 days at 20$^{\circ}C$, 10.7 days at 25$^{\circ}C$, and 5.8 days at 30$^{\circ}C$. Mean fecundity per female was higher at 20$^{\circ}C$ compared with at other temperatures. The developmental zero point temperatures (1) and the total effect temperatures (I<) of egg, larva, pupa, and complete development were 10.6, 14.0, and l3.1$^{\circ}C$ and 214.8, 1,564.8, and 229.2 degree-days, respectively. Mean generation time in days (T) was shorter at higher temperature. Net reproductive rate per generation (Ra) was the lowest at the highest temperature as well as at the lowest, and it was 177.19 which was the highest at 23$^{\circ}C$. The intrinsic rate of natural increase (r$\sub$m/) was highest at 27$^{\circ}C$ as 0.019. As a result, optimum range of temperature for L. lateralis growth was between 20-25$^{\circ}C$.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.163-168
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• 2008

Temperature dependent development of Tetranychus. urticae Koch was studied on the leaf of eggplant at 17, 22, 27, 32 and $37^{\circ}C$. T. urticae showed a minimum mortality at $27^{\circ}C$ and it increased at higher or lower temperatures than $27^{\circ}C$. The hatchability was low at 17 and $37^{\circ}C$. The duration of development decreased with increasing temperatures i.e., 5.3d at $37^{\circ}C$ and 25.8d at $17^{\circ}C$. Linear regression analysis of temperature vs. rate of development yielded the higher $r^2{\geq}0.88$ resulting in a good fit of the estimated line in the range of $17{\sim}37^{\circ}C$. Developmental zero temperature was $12.5^{\circ}C$ for the entire immature stage of female and $12.8^{\circ}C$ for that of male. Thermal constants were 80.5 and 74.7 degree days for those of female and male, respectively. Adult life span and oviposition period decreased with increasing temperatures. The number of eggs laid per female peaked at 141.0 eggs at $27^{\circ}C$, while that was a minimum 78.0 eggs at $37^{\circ}C$. Rate of hatchability, ratio of female, and $R_o$ were increased up to $27^{\circ}C$, and than declined thereafter. Intrinsic rate of natural increase (Rm) increased with rising temperatures and showed a maximum 0.5652 at $37^{\circ}C$. Also, ${\lambda}$ increased with increasing temperature. Doubling time (Dt) and generation time (T) decreased with increasing temperature.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.183-191
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• 2023

After examining the temperature change in berry sawdust during the fermentation period and the developmental characteristics of Protaetia brevitarsis larvae according to the fermentation period, it was found that the fermentation speed was faster than with oak sawdust and a fermentation period of 50-70 days was the most suitable for larval growth. During the fermentation period, the temperature change in sawdust was quickly fermented as berry sawdust passed a high temperature of more than 60℃ in the early stages of fermentation compared to fermentation speed of oak sawdust, and stabilized within 60 days. In individual breeding, the total growth period of P. brevitarsis larvae by fermentation period was the longest at 104.8 days after fermentation for 30 days, which was a significant difference. There was no difference in the growth period between 50 and 90 days of fermentation. Oak sawdust tended to be the same as berry sawdust, but the larval development period was approximately 30 days. The developmental period by larval stage differed greatly between berries and oak sawdust. The weight of larvae according to the fermentation period of sawdust was the lowest after 90 days of fermentation, with a long fermentation period for both berry and oak sawdust, and there was no difference in the 30-70 days fermentation periods. The survival rate was more than 95% in individual breeding, and there was no difference among the fermentation periods. However, in group breeding, the survival rate was lower than that of individual breeding and was lowest at 90 days of fermentation. In group breeding, the ratio of larvae weighing ≥ 2.5 g, which is the standard for shipment, was 85% after 30-70 days of fermentation of berry sawdust, but was lower at 70% after 90 days of fermentation, which was a significant difference. The survival rate with oak sawdust showed the same trend, which was approximately 10% lower than that with sawdust. In addition, the larvae from the berry sawdust weighed > 2.5 g in 40-60 days, while it took 75-105 days with oak-fermented sawdust.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.19-19
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• 2003

소 난자 체외성숙에 있어 소 태아혈청 (fetal bovine serum: FBS)첨가시 높은 성숙율을 보이며 핵 이식 후 배 발달율에 있어서도 높다. 하지만 소 태아혈청은 hormone, growth factor, vitamine 그리고 다수의 어떤 잘 알려지지 않은 인자를 포함한 복잡한 배지로 알려져 있으며, 수정란 이식 후 태아의 발육중 및 태어난 직후에 발생되는 송아지에서 나타나는 몇몇 비정상적인 현상들의 원인인 것으로 보고되고 있다. 본 실험은 체외 배양시 소 태아혈청과 이의 대체물질로서 BSA 또는 PVA가 첨가된 배양조건에서의 복제 수정란의 배 발달율을 비교함과 동시에 배반포의 세포수 그리고 세포자연사 (Apoptosis)를 각각의 조건에서 비교함으로써 배발달에 미치는 효과를 알아보기 위하여 실시하였다. 핵이식은 소 체세포를 이용하였으며, 핵 이식 후 CR1aa 기본 배양액으로 FBS, BSA, 그리고 PVA를 첨가하여 5% $CO_2$, 5% $O_2$, 39$^{\circ}C$ 조건하에서 7~8일간 배양하였다.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.431-436
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• 2013

Ricania sp. lay eggs into the new twigs of blueberry and suck nutrients causing growth retardation and a sooty mold symptom. This study was conducted to investigate the emergence success and developmental period of overwintered eggs of Ricania sp. under the seven constant temperatures from 10 to $34^{\circ}C$ by $4^{\circ}C$ intervals (14L:10D). We also monitored the emergence time of the Ricania sp. nymph at blueberry by 3 ~ 4 day interval using a modified leaf clip cage. Development times from the overwintered egg to $1^{st}$ nymph were 107.1, 54.5, 33.9, 25.3, 25.1 and 16.7 days and the emergence successes were 23.1, 30.8, 13.8, 21.7, 11.9, and 0.6% at 14, 18, 22, 26, 30 and $34^{\circ}C$, respectively except at $10^{\circ}C$. The developmental periods were decreased with increasing temperatures. First emergence date of the nymphs in the field was between 19 and 22 May, and the average emergence success was 19.6%. The present study might be helpful to establish the management strategy of Ricania sp. based on the biological characteristic.

• Korean journal of applied entomology
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• v.36 no.4
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• pp.317-322
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• 1997

Hatched-larvae of the mulberry longicorn beetle, Apriona germari Hope, collected from mulberry fields were reared on artificial diet at 25$^{\circ}$C with 14 h light and 10 h dark to study the larval developmental characteristics. Artificial diet developed for rearing silkworm was used with minor modification adding mulberry branch powder. In case of artificial diet rearing, the head width of larval instar from the I st to the 12th instars was ranged from 0.12 to 0.69cm, and growth rate of each instar was significantly high between the I st and the 2nd instars. In addition, the weight of the 8th instar larvae was increased approximately 176-fold in comparision with that of the 1st instar larvae. Larval duration of each instar took long with larval developmental stages, and that of the 1st to the 9th or the 12th instars was 186.03 or 304.58 days, respectively. The survival rate of larvae was 40.8% by the 8th instar. The pupation rate was approximately 32.4%. Furthermore, although pupation stage was broadly appeared from the 7th to the I lth instars, pupation was majorly observed at the 8th and the 9th instars.