• International Journal of Industrial Entomology and Biomaterials
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• 제5권1호
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• pp.1-12
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• 2002

Ecophysiologically diapause represents a syndrome of physiological and biochemical characteristics, all of which ensure survival during a long period of dormancy. Since, silkworm enters diapause as embryo at the early embryonic stage, the duration of egg life depends on the duration of embryonic diapause. The nature of diapause in silkworm, Bombyx mori, is primarily determined by genetic characters and endocrinologicnl mechanisms, mediated by environmental factors such as temperature and photoperiod. Hibernating potency value besides nucleic acid and carbohydrate metabolism, production and utilization of sorbitol are also equally responsible for induction, initiation, determination, maintenance and termination of diapause. Embryonic diapause in Bombyx moir, induced by active secretion of sub-oesophageal ganglion is attributed to hormonal system and metabolic adjustment, which serves to bring about a new physiological state. Metabolic conversion of trehalose to glycogen at induction, glycogen to sorbitol at initiation and sorbitol to glycogen at termination of diapause is correlated and in each metabolic shift a key enzyme becomes active in response to hormonal and environmental stimulation. An attempt has been made in this review article to discuss briefly the nature of embryonic diapause, influence of various factors on diapause nature, hormonal mechanism of diapause besides biochemical composition of egg, nucleic acid and carbohydrate metabolism, production and utilization of sorbitol in relation to induction, determination, maintenance, initiation and termination of diapause in the silkworm, Bombyx mori.

• 한국응용곤충학회지
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• 제29권4호
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• pp.277-285
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• 1990

담배나방 (Heliothis assulta Guenee)의 용휴면에 대한 유기와 종료요인 및 휴면 지속기간 등에 대하여 실험실과 야외개체에 대하여 실험하였다. 일장과 온도조건이 용휴면유기에 밀접한 관련을 맺으며 $20^{\circ}C$와 lOL/140의 팡주기하에서 유충율 키웠을 때 100%의 휴면율을 얻을 수 있었다. 그러나 $25^{\circ}C$의 경우에는 본 실험에서 시도한 가장 짧은 광주기인 8시간하에서도 약 85%의 휴면율만 나타내었다. 결국 휴면을 유기하는 임계일장이 $25^{\circ}C$에서는 12-12.5시간, $20^{\circ}C$에서는 14-14.5시간으로 계산되었으며 휴면유기 조건에 감응하는 발육단계는 4령과 5령유충기였다. 수원 및 우리나라 중부지역에서 9월 20일경부터 채집되는 노숙유충은 모두 휴면으로 들어갔다. 그러나 성충, 알, 용 등은 실험실내 휴면유기 조건 ($20^{\circ}C$, lOL/140)에 처리해도 아무런 반응이 없었다. 휴면기간은 휴면유기온도가 낮으면 길어지는 경향이었으며 광주기와는 무관한 것으로 나타났다. 휴면용들은 저온처리를 받지않아도 깨어나지만 저온처리 기간이 길어질수록 휴면기간은 짧아졌다.

• 한국잠사곤충학회지
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• 제27권1호
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• pp.24-30
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• 1985

휴면(성)란을 수종의 유기용매에 침적처리 후 휴면개시의 조지 및 휴면타파에 관한 이들 용매의 효과를 조사.검토했다. 잠란의 침적처리에 사용한 유기용매 중 메칠알콜과 벤젠은 휴면개시를 조지하여 배자발육을 지속시키는데 효과적이었으나 클로로포름 및 클로로포름-메칠알콜(2:1)의 혼합용액은 무효했다. 특히 메칠알콜이 유효하여, 산란후 5시간이 경과(5시간령)한 금추$\times$종화의 잠란을 메칠알콜에 2분, 5분, 10분간 침적처리하면 약 70~80%가 부화했고, 20시간령란에서는 약 10%의 부화잠이 얻어졌다. 이러한 메칠알콜의 효과는 휴면개시 이전의 잠란에서만 확인되었고, 휴면초기인 2일령, 3일령 및 6일령의 잠란에서는 유기용매의 종류 및 침적 처리 시간의 장단에 불구하고 부화잠 및 최청사란은 출현하지 않았다. 휴면성에 미치는 유기용매의 효과에 이 같은 시기의존성이 있는 것으로 휴면의 개시와 각성은 각기 다른 기구에 의해 유도되는 것으로 생각된다. 또한 메칠알콜에 의해 추출되는 잠란의 지질 성분의 종류 및 양, 그리고 현재까지 알려져 있는 휴면성과 난각의 연속성 등으로 보아 휴면개시를 조지하는 메칠알콜의 시용부위는 난각일 것으로 추찰된다.

• 한국응용곤충학회지
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• 제27권1호
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• pp.6-13
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• 1988

흰불나방 (Hyphantria cunea Drury) 의 용휴면이 결정되는 시기, 휴면용에서의 20-hydroxyecdysone 의 영향과 전기영동 방법으로 측정된 용단백질의 변화는 다음과 같았다. 용휴면의 결정은 유충발육기간중 초기 5~15일에 이루어졌다. 산소소비율의 변화는 정상발육용에서 U자 모양의 곡선을 나타내었고, 휴면용에서는 $30mu$l {TEX}$O_{2}${/TEX} /g/hr 수준으로 감소되어 유지되었다. 휴면용에서 추출된 2.5%균질액은 20-hydroxyecdysone 의 처리로 호흡활성이 증가하였고, 휴면예정용은 직접 주사로 우화하였다. 수용성 단백질의 함량 변화는 정상발육용에 급격하게 이루어졌으나, 휴면용에서는 완만하였고, 더 많은 양이 포함되어 있었다. 휴면예정용의 지방체에서 분리한 단백질의 종류는 비휴면용의 경우와 달랐다.

• 한국응용곤충학회지
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• 제26권3호
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• pp.139-144
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• 1987

흰불나방의 용 휴면(休眠) 유기(誘起)와 월동휴면 종료(終了)시기를 조사한 실험에서 다음의 결과를 얻었다. 1. $25{\pm}1^{\circ}C$온도 조건에서 휴면유기의 임계일장은 14시간과 14시간 30분 사이에 존재하였다. 2. 유충 발육기간은 $25{\pm}1^{\circ}C$조건에서 일장이 길어질 수록 약간씩 단축되었다. 3. 야외에서 월동휴면 종료는 12월하순 이후에 부분적으로 시작되었으며 그 이전에 꺼낸 용은 성충으로 전혀 우화되지 않았다.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 1997년도 Progress and Future Development of Sericultural Science and Technology 40th Anniversary Commemoration Symposium
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• pp.51-72
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• 1997

Diapause hormone (DH) is a neuropeptide hormone which is secreted from the suboesophageal ganglion (SG) and is responsible for induction of embryonic diapause of the silkworm, Bombyx mori. DH is isolated from SGs and determined to be a 24 amino acid peptide amide. The cDNA encodes the polyprotein precursor from which DH, pheromone biosynthesis activating neuropeptide (PBAN) and three other neuropeptides are released and become matured. The C-terminal FXPRL-NH2 sequence of DH is essential but not sufficient for expression of full activity. Recently, we have isolated a unique hydrohobic peptide (VAP peptide) with a slight diapause egg induceing activity from organic solvent extracts of the male adult heads of the silkworm. The VAP peptide itself has no diapause inducing activity, but enhances DH activity through reducing ED50 value and the threshold concentration of DH. The DH-PBAN gene is composed of 6 exons interrupted by 5 introns and is expressed in 12 neurosecretory cells of the SG. The incubation of eggs at 25$^{\circ}C$, which induces embryonic diapause in the progeny, caused DH-PBAN mRNA content to increase at 5 different stages in the life cycle. By contrast, a 15$^{\circ}C$ incubation only induced expression of the gene at the late phrase adult stage. The temperature-controlled expression of DH-PBAN gene is closely correlated to the incidence of diapause, indicating that DH-PBAN gene expression is the initial event leading to diapause induction. DH acts to stimulate trehalase activity in developing ovary to bring about hyprglycogenism in mature eggs, a prerequisite metabolism for diapause initiation. Using in vivo and in vitro systems, DH is clearly shown to induce trehalase gene expression in developing ovaries. New protein synthesis is not needed for this process, but a Ca2+-dependent proteinkinase seems to be involved. Quite recently, we have sucessfully applied a new and potent trehalase inhibitor (Trehazoline) to reudce glycogen content in developing ovaries. The eggs deficient in glycogen were also able to enter diapause as the natural eggs do, so that we could provide the new egg system to reconsider the diapause associated metabolism other than the glycogen-sorbitol metabolic system.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 International Symposium of Silkworm/Insect Biotechnology and Annual Meeting of Korea Society of Sericultural Science
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• pp.95-96
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• 2003

We investigated the proteins that are associated with initiation, maintenance, and termination of diapause in silkworm eggs by means of 2D-gel electrophoresis. 1. Materials : Bombyx mori: unfertilized eggs, diapause eggs, non-diapause eggs, cold-treated egges. 2. Methods: isoelectric focusing, SDS-PAGE, silver staining. (omitted)

• International Journal of Industrial Entomology and Biomaterials
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• 제23권2호
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• pp.207-213
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• 2011

The diapause of $Telegryllus$ $emma$, the Emma field cricket, was investigated to study the ecological characteristics of the species. Changes in the volume, oxygen consumption, and water content of T. emma eggs were followed from oviposition. An increase in volume, oxygen consumption and water uptake occurred from 7 to 8 days following oviposition. The oxygen consumption of the eggs increased slowly for 7 days following oviposition, but then decreased until 15 days following oviposition. These results showed that a physiological change at diapause initiation affected the volume, water content, and oxygen consumption of the $T.$ $emma$ eggs. An experimental investigation of egg hatching showed that the eggs could be stocked at $10^{\circ}C$ for 40 days with a 14 day pre-period after laying and yield, 62.1% hatchability under these conditions. Maintaining the temperature at approximately $10^{\circ}C$ was favorable for hatching. Another experiment on egg hatching showed that the storage of eggs at $10^{\circ}C$ from 40 to 180 days would ensure satisfactory, hatching capacity.

• International Journal of Industrial Entomology and Biomaterials
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• 제15권1호
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• pp.75-78
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• 2007

To define the molecular mechanism of initiation and termination of diapause during the embryogenesis of silkworm, Bombyx mori, mRNA transcripts from diapausing eggs and diapause activated eggs were compared with differential expression using cDNA array. Among those clones, mRNA transcript from hsp20.8A, which was expressed at a high level in diapausing eggs that had been incubated at $25^{\circ}C$ for 30 days after oviposition, whereas, in the eggs exposed to $15^{\circ}C$ for 30 days, $5^{\circ}C$ for 60 days, the expression of mRNA decreased. On the other hand, the expression of mRNA during embryogenesis observed abundantly at 4 to 6 days after heat-HCl treatment and later at 9 to 10 days after just before hatching. This result was suggested for us that hsp20.8A was expressed in response to embryogenesis as well as physical stress.

• International Journal of Industrial Entomology and Biomaterials
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• 제22권2호
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• pp.29-37
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• 2011

Commercially managed bees are available for pollination services and are used in large commercial fields, small gardens, or enclosures such as greenhouses and screen houses. This paper describes the current status and agricultural utilization of commercially managed bumblebees as well as bumblebee rearing techniques in Korea. We surveyed the use rate and number of bumblebees for the pollination of 10 major horticultural crops and fruit trees in Korea; in 2009, the use rates were approximately 7.9% and 2.8%, respectively. The use number of bumblebees as pollinators was more than 64,345 colonies, which included 51,400 colonies for 10 major horticultural crops and 12,945 colonies for 10 major fruit trees in 2009. The value of bumblebees as pollinators in 2009 in Korea was estimated at more than 5,100,000,000 won. We also describe feeding, rearing room conditions, colony initiation, mating and diapause breaks to establish year-round mass rearing techniques of the bumblebee Bombus ignitus.