• Journal of Sericultural and Entomological Science
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• v.49 no.1
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• pp.1-7
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• 2007

We investigated the selection and sensitivity to environmental mutagen of silkworm reared artificial diet to develop all-year-round operation system using a specific locus mutation of Bombyx mori. In the system, mutagenicity could be detected by the egg colour manifested by the pe and/or re genes, which is a kind of recessive visible mutation of the insect. Among, hi, Backokjam, C5, and N12, varieties of silkworm, AT was higher than other varieties in eclosion rate of female, and C5 and N12 were higher in fertility of male. Bakokjam was higher in eclosion rate of female, rate of moth to lay eggs normally in female and male, no. of eggs layed in female and fertility of female. As above results, Bakokjam was finally selected as the most fitness one among varieties of silkworm reared artificial diet. But the sensitivity to mutagen was lower than other varieties. In the sensitivity to mutagen, AT was the most sensitivity to mutagen in tested varieties of silkworm. To use AT variety in this system, AT was improved major characteristics, eclosion rate, fertility, rate of moth to lay eggs normally, and so on, by crossing of other varieties including Bakokjam.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.125-130
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• 2005

The ecological characteristics of the specialist insect predator, Oligota kashmirica benefica, were investigated for developing artificial rearing method with special interest on the oviposition behavior, the pattern of adult emergence and temperature in storage, and its effect on the density of the citrus red mite, Panonychus citri. Female beetle oviposited eggs mainly, $95\%$ of the eggs, on the bottom of leaves of the yuzu tree, and $91.3\%$ of them were covered with ecdysis skin of the red mites or the feces of themselves. The rate of adult emergence of the beetle rose up to $86.7\%$ when the horticultural media was provided for pupation from $60\%$ when it pupated in upland soil. Most larvae, $88\%$ of them, were found from the surface to the depth of 2 cm in the horticultural media. The optimum temperature for the storage of the adult beetle was found to be $12^{\circ}C$, at this temperature the 96.7, 73.3 and $70.0\%$ of the beetle survived for 10, 20, and 30 days, respectively. The control effect of the citrus red mite was appeared highest by releasing the beetle at the rate of one beetle against 150 mites.

• Korean journal of applied entomology
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• v.30 no.4
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• pp.249-257
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• 1991

Chronological changes in the occurrence pattern of the striped rice borer(SRB), Chilo suppressalis Walker, were investigated by analyzing the data collected by 33 light traps of the countrywide monitoring units during the period of 1968-1989. And also relation of incidences between larval and adult populations, emergence time and percent emergence of overwintered larvae were observed in relation to the time of different rice transplantations. Spring moths of SRB in 1985-'89 generally emerged earlier than in 1968-'72 : 30 days earlier at Kwangju, 20 -25 days earlier at Sangju and Naju, 10-15 days earlier at Uljin, Jinju, Goyang, Milyang, Kimhae, etc., 5 days earlier at Suweon, Jinchun, Daejeon, Namweon, Haenam, etc. There was no change in the time of spring moth emergance at Weonseong, Chungju, Seosan, Yongju, and Nonsan. Summer moths of SRB in 1985- '89 also emerged earlier than 1968- '72: 20 days earlier at Uljin, 15 days earlier at Chungju, Yeongdug, and Habchun, 5-10 days earlier at the other areas except Yeongju. There was an overall countrywide decrease in the population of the 1st generation of SRB during the last two decades. The population of the 2nd generation also decreased in 19 areas during the same period, but increased in 14 areas including over 3-fold increases in Kwangju, Naju and Daegu, and double increase in Jinju, Milyang and Gongju. The higher larval population density of 1st genration was taken place in the earlier transplanted fields, whereas the population of 2nd generation were higher at mid-season transplanted (May 30), followed by May 15, June 15, and April 30. The peak of larval population appeared generally 15 days after moth peak in 1st generation, and 10 days after moth-peak in 2nd generation. The earlier transplanted fields were the higher percent damage due to 1st off-springs of spring moths, whereas the fields transplanted in mid-season were higher damage due to 2nd off-springs of summer moths. Average body weights of SRB larvae before overwintering were 65.6 mg, 61.2 mg, and 55.5 mg in early, mid-season, and late transplantations, respectively. In field cage experiments, emergence rate of the overwintered larvae ranged from 28.3-39.8%. In other words, body weights of overwintering larvae were heavier in fields by earlier transplantation, and heavier larvae showed higher percentage of adult emergence. The period from overwintered larvae to adult emergence was longer in the fields of the later transplantations; namely, 44, 49, and 51 days for early, mid-season, and late transplantations, respectively.

• Korean journal of applied entomology
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• v.13 no.1 s.18
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• pp.11-16
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• 1974

Experiment was conducted to select the rice varieties and lines resistant to the smaller brown planthopper, Laodelphax striatellus Fallen, and study the cause of varietal resistance to the insect. The nature of varietal resistance was evaluated from the viewpoints of feeding and ovipositional preferences and antibiosis. Among the IRRI sources the varieties H 105, Muthumanikam, Vellailangalayan, Karsamba Red ASD-7. Manavari Co 22, Mudgo, PTB-18, IR 8 and IR 20 were selected as resistant sources. Among the domestic sources. only Suweon 213-1, Suweon 214 and Suweon 215 originated from the IR667 lines were resistant, and other leading varieties ail susceptible. The cause of resistance of rice to the insect seemed to be highly related with the non-feeding preference, not non-ovipositional preference. Nymphal mortality and rate of adult emergence were significantly different from the resistant and susceptible varieties. The rate of adult emergence was significantly lower in the resistant than In the susceptible varieties. The primary cause of lower adult emergence seemed to be due to the fact that the infects were suffered higher nymphal mortality in the resistant than in the susceptible varieties.

• 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.

• The Korean Journal of Pesticide Science
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• v.3 no.2
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• pp.74-80
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• 1999

These studies were carried out to investigate the effects of nonsteroidal ecdysone agonist, tebufenozide on embryonic and postembryonic development of sycamore lace bug, Corythucha ciliata. Tebufenozide exhibited ovicidal activity($LC_{50}=4.0$ ppm). Susceptibility of each instar nymphs to tebufenozide was nearly same($LC_{50}=2.3{\sim}6.0$ ppm). The tebufenozide treatment in the final instar affected the emergence, longevity and fecundity of surving adults significantly. Tebufenozide applied at high concentration (10 ppm) to younger adults delayed prioviposition period, and decreased adult longevity, the number of eggs laid per female and hatchability. The treatment also inhibited the ovarian development of the female adults.

• Korean journal of applied entomology
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• v.13 no.2 s.19
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• pp.89-92
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• 1974

This experiment was carried out to investigate the X-ray sterilization of house fly, Musca domestica when 3-5 days old pupae were irradiated. The results obtained were summerized as follows; 1) Sub-lethal dosage (LD50) for tile pupal mortality were 12.2-13.1 kRad. 2) Sterile dosage (SD90) showed 3. 1kRad in male and such low dosage appears adequate as a sterile dosage. 3) The mortality of male flies was significantly higher than in female at the doses of 4 and 5 kRad.

• Korean journal of applied entomology
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• v.52 no.3
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• pp.249-253
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• 2013

The adzuki pod worm, Matsumuraeses phaseoli (Matsumura) is an insect pest that attacks the flowers and pods of Vigna angularis. The circadian rhythms of eclosion and mating, and the effects of age and antenna ablation on mating success, were investigated. With a photoperiodic regime of 16:8 (Light:Dark) h, most adult eclosion was observed within 4 h after lights-on. Most adult mating was observed during the scotophase, although some occurred within 2 h after lights-on. However, the adults did not copulate on the day of emergence. The mating rate increased with adult age: being higher in the 4-d-old adult pairs than pairs of lower age. Most of the antennectomized males or females did not copulate with normal individuals of the opposite sex.

• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.266-273
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• 2019

Heavy metal contamination in freshwater ecosystem has been receiving increased worldwide attention due to their direct or indirect effect on human health and aquatic organisms. In this study, we investigated biological effects such as survival rate, growth rate, emergence rate, sex ratio and mouthpart deformity of Chironomus plumosus. The survival rate of C. plumosus decreased with the increase in heavy metal concentration as well as exposure time after cadmium (Cd) or zinc (Zn) exposure. The growth rate decreased at days 4 and 7 after Cd exposure and significantly reduced at the relatively high concentration of $50mg\;L^{-1}$ Cd. The emergence rate was decreased at $50mg\;L^{-1}$ Cd and $100mg\;L^{-1}$ Zn. The sex ratio showed imbalance pattern at relatively low concentrations (0.5 and $2mg\;L^{-1}$ Cd) with high proportion of male and relatively high concentration ($100mg\;L^{-1}$ Zn) with high proportion of female (60%). In addition, mentum deformities were observed at high concentration of Cd and Zn. These results suggest that heavy metal exposure in aquatic ecosystem may affect biological and morphological responses, and aquatic midge C. plumosus is a potential indicator for assessment of environmental pollutant such as heavy metals.

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