• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.2
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• pp.180-183
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• 2010

This study was performed to investigate the temperature-dependent development, longevity and oviposition of an indigenous larval parasitoid, Meteorus pulchricornis, on tobacco cutworm, Spodoptera litura. M. pulchricornis were reared at nine constant temperatures between 15 and $35^{\circ}C$. The developmental times of each three developmental stage decreased from 38.7 to 16.3 d between 15 and $30^{\circ}C$. However, M. pulchricornis showed longer developmental time at $32.5^{\circ}C$ (9.5, 7.7 and 17.2 days for each three developmental stage) than at $30^{\circ}C$ (8.9, 7.3 and 16.3 days for each three developmental stage). Immature M. pulchricornis could not develop any more at $35^{\circ}C$. The lower developmental threshold estimated by linear regression equation for the egg to cocoon, cocoon to adult emergence and egg to adult emergence were 5.1, 4.6 and $4.5^{\circ}C$. The thermal constant for each of the three stages were 217.2, 176.2 and 403.8 degree-days, respectively. When no food or 50% honey solution as a food source is provided for M. pulchricornis, the parasitoid survived for 8.3 and 55.9 days at $25^{\circ}C$, respectively. M. pulchricornis females laid 5.2 eggs daily and total of 131.6 eggs at $25^{\circ}C$ until it died. Peak age-specific fecundity was observed on $14^{th}$ day (9.6 cocoons) after parasitoid emergence and gradually decreased thereafter.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.05a
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• pp.196-196
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• 2002

• Journal of Sericultural and Entomological Science
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• v.35 no.1
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• pp.28-35
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• 1993

Treatment of juvenile hormone analogue(JHA) at the 5th instar larvae prolonged the duration of adult development one to one and half days as well as the elongation of feeding time with the increasing of larval body weight. Morphological observation and protein analysis in hemolymphs, integuements, alimentary canals, fat bodies and ovaries also revealed that the development of these tissues and organs for adultation are affected by the JHA treatment.

• Korean journal of applied entomology
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• v.25 no.1 s.66
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• pp.27-32
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• 1986

To establish a method for measuring varietal resistance against rice stem maggot in field and pot, 20 varieties were used in $1981{\sim}1983$. The degree of injured stems by the 1st generation larvae was significantly correlated with that of injured panicles by the 2nd ($r=0.864^{**}$). There was no ovipositional preference in rice stem maggot. The larval mortality after artificial infestation varied widly from 5.6 to 100% in varieties and that of the resistant varieties was high after boring. There was a negative correlation between number of injured leaves and larval mortality after artificial infestation ($'81:r=-0.833^{**},\;'82:r=-0.918^{**}$). It is considered that larval mortality mainly caused by antibiosis and larval mortality 20 days after infestation on rice seedlings is ideal for evaluating the varietal resistance to rice stem maggot. Resistant varieties are Nagdongbyeo, Jinjubyeo and Chucheongbyeo susceptible varieties, Keumgangbyeo, Milyang 23, Baigyangbyeo and Milyang 30.

• Journal of Aquaculture
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• v.12 no.2
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• pp.115-122
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• 1999

Exposure experiments during the egg development were conducted to assess the influences of 5 different concentrations (0, 25, 50, 75 and 100%) of water-soluble fraction (WSF) of Kuwait crude oil on the eggs and larvae of black seabream (Acanthopagrus schlegeli), red seabream (Pagrus major) and olive flounder (Paralichthys olivaceus). All experiments were triplicated. Hatching time and hatching rate were examined on the eggs. The median lethal time ($LT_{50}$), morphological abnormality and swimming activity (swimming frequency and speed) of larvae were also investigated. The time and rate of egg hatching were not significantly influenced by WSF on the eggs of the fishes. The larvae exposed to WSF during the egg development were also not significantly influenced on the $LT_{50}$ and swimming activity. But the higher morphological abnormalities of notochord were observed from the larvae in 100% WSF exposure.

• Journal of Environmental Health Sciences
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• v.28 no.4
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• pp.17-22
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• 2002

In crustaceans, as in other arthropods, the molt cycle and the physiological process of growth are controlled by molting hormones (MH) which are steroid hormones, the ecdysteroids. Ecdysteroids are major arthropod hormones which control both development (embryonic and larval molts, metamorphosis) and reproduction. The purpose of the present study was to evaluate both fenarimol and methoprene for embryotoxicity to daphnids. The embryotoxicity associated with each compound was assessed to discern whether the embryotoxicity of methoprene might be due to ecdysone agonist and the ecdysone antagonistic effects of fenarimol on Daphnia embryo. Exposure of daphnids for three weeks to 50 M methoprene resulted in a significantly high incidence of offspring that exhibited general toxicity. This exposure concentration had significant effects on the overall number of embryo death. However, exposure to 3 or 1 $\mu$M fenarimol were no significant effects on the embryo toxicity. The incidence of both of these toxicity increased with methoprene exposure. This observation suggest that methoprene showed embryonic general toxicity during embryo development, while, only fenarimol showed weak general toxicity with early stages of embryonic development.

• The Korean Journal of Zoology
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• v.36 no.1
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• pp.84-96
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• 1993

한국산 도롱뇽(Hynobius leechii) 유생의 다리 발생 과정을 관찰하고 잠재적 돌연변이 유발물질인 제-methyl-N'-nitro-N-nitrosoguanidine(MNNG)과 잠재적 기형 유발물질인 retinol palmitate가 다리 발생에 미치는 영향을 알아보았다. 정상적인 개체에서 됫다리의 발생 단계는 외부와 내부의 형태적 특징을 기준으로 하여 7단계로 나누어 볼 수 있었으며 전연골세포의 밀집에 따른 골격형성은 다리 발생아의 근위부에서 시작하여 원위부로 진행됨을 확인할 수 있었다. 도롱뇽 유생을 MNNG(10 rpm)나 retinol palmitate(37.5 lpm)로 처리한 경우, 공통적으로 다리 원위부의 골격 형성이 억제되었으며, 특히 이러한 골격 형성 억제 현상은 처리시기가 이를수록 보다 심하게 나타났다. 이러한 결과는 발생을 저해하는 물질에 대한 미분화 상태의 세포들의 반응성이 발생과정 중 특정 단계에 국한됨을 시사하는 것으로 해석된다.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.2
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• pp.203-208
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• 2003

Rearing temperature influences food consumption, conversion and cocoon production in silkworm Bombyx mori L. Young age $({1^st}to{3^rd} instar)$ worms of Pure Mysore, a multivoltine were reared at 26, 28, 30 and $32^{\circ}C$ followed by combinations of these temperature levels during late age $({4^th} and {5^th} instar)$. Food consumption, conversion, larval duration and growth for each instar were recorded. The influence of combinations of these temperature levels during rearing on survival and cocoon production was assessed. Food consumption increased with the temperature up to $4^th$ instar and decreased during $5^th$ instar. Temperature beyond $28^{\circ}C$ during young age followed by higher temperature ($30^{\circ}C$ and above) has shown deleterious effect on cocoon production. The paper discusses the rearing performance in relation to food intake and conversion under the tested temperature levels.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.269-272
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• 2004

Different methods of cold storing of bivoltine eggs are in practice to postpone hatching. Bivoltine eggs undergo hibernation if they are not acid treated within 20 - 24 hrs of oviposition, which depends on race, ambient temperature and humidity. The schedules adopted for cold storing include hibernation schedule (Hib), ordinary chilling (OC), short term chilling (STC) and acid treated layings (AT). Peanut cocooning race ${NB_4}{D_2}$ has been subjected for the present assessment. Cocoons harvested from the crop pertaining to all the four methods of cold storing have been used for producing different combinations and acid treated followed by rearing. The performance in respect of chawki loss, maximum larval weight 4({5^th} age)$, yield/ 10,000 larvae (no), cocoon and shell weight showed maximum values for hibernation ${\times}$ hibernation combination followed hibernation with OC and hibernation with AT. Lowest performance was recorded when STC batch source females were used.

• Molecules and Cells
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• v.47 no.1
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• pp.100006.1-100006.10
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• 2024

Nitric oxide (NO) serves as an evolutionarily conserved signaling molecule that plays an important role in a wide variety of cellular processes. Extensive studies in Drosophila melanogaster have revealed that NO signaling is required for development, physiology, and stress responses in many different types of cells. In neuronal cells, multiple NO signaling pathways appear to operate in different combinations to regulate learning and memory formation, synaptic transmission, selective synaptic connections, axon degeneration, and axon regrowth. During organ development, elevated NO signaling suppresses cell cycle progression, whereas downregulated NO leads to an increase in larval body size via modulation of hormone signaling. The most striking feature of the Drosophila NO synthase is that various stressors, such as neuropeptides, aberrant proteins, hypoxia, bacterial infection, and mechanical injury, can activate Drosophila NO synthase, initially regulating cellular physiology to enable cells to survive. However, under severe stress or pathophysiological conditions, high levels of NO promote regulated cell death and the development of neurodegenerative diseases. In this review, I highlight and discuss the current understanding of molecular mechanisms by which NO signaling regulates distinct cellular functions and behaviors.