• International Journal of Industrial Entomology and Biomaterials
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• 제18권1호
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• pp.1-7
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• 2009

Quality of seed in the mulberry silkworm, Bombyx mori (L.) is determined by many important factors, wherein unfertilized eggs play an important role. Unfertilization of eggs are caused by several reasons such as, abnormality in the sexual organs of the male and female, abnormal development of the micropylar end of the egg, unfavorable environmental conditions during spinning, cocoon preservation, imperfect handling of moths, mating, ovipostion, cold storing of pupae / moths and indiscriminate use of male moths etc. Though the presence of unfertilized eggs would in no way affect the fertilized ones and their quality directly, the frequency of their occurrence underrates the quality and brings down the hatching percentage. Lower the occurrence of unfertilized eggs, higher is the rating of seed quality. Of the various intrinsic and extrinsic factors and events involved in egg deposition of an adult silk moth, mating is an instinct and a biological obligation for the ultimate perpetuation of the species and a must to provide stimulus for oogenesis and bring about biochemical changes in the spermatophore of the silkworm in order to ensure the presence of sufficient number of normal sperms and testicular fluid in the female reproductive organ, activating ovulation and accelerating oviposition behavior and egg deposition. An attempt has been made in this article to briefly elucidate the characteristics of unfertilized eggs, causes of their occurrence and its impact as well as the significance in silkworm seed production.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권2호
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• pp.139-143
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• 2004

It was investigated whether developmental characteristics of foundation queens of Bombus ignitus collected in the 4 localities in Korea would be affected by the first oviposition days of them. The first ovipostion day was classified as 1-4 days (immediate early), 5-6days (early), 7-10 days (delayed early), 11-20 days{medium), 21- 40 days (late), and above 41 days (very late). The queen that had the early first oviposition day, i.e., laid eggs so early after starting to be raised indoors, showed much higher rate of colony foundation and progeny-queen production and much shorter period of colony foundation and worker emergence. Besides, the numbers of worker and progeny-queen emerged from the queen that had the early first oviposition day were higher than those of the queen that had the late first oviposition. In results, the queen that had the early first oviposition day could make colony stronger and could make colony formation period shorter, therefore, the first oviposition day of foundation queen was proved to be a criterion for the selection of super colonies when B. ignitus is raised indoors.

• 한국잠사곤충학회지
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• 제28권2호
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• pp.35-37
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• 1986

수세대의 계대동육에 의해서도 휴면란이 얻어지지 않는 열대성 다화성 누에의 품종보존을 위한 사육회수를 줄이고자 다화성 누에씨(MR, SPT, HM)의 냉장적기, 냉정적온 및 냉장가능기간을 부화비율을 지표로 하여 조사한 바 다음과 같은 결과를 얻었다. 1. 5$^{\circ}C$에서 30일간 냉장한 MR과 SPT의 부화비율은 2일영난냉장구에서 가장 높았고(약 80%), 7일영난냉장구에서 가장 낮았다(5% 이하). 2. 2일영의 HM누에씨를 -2.5, 0.0, 2.5, 5.0, 7.5$^{\circ}C$의 각 온도에 15일-60일간 냉장하여 부화비율을 조사한 결과, 30일 냉장에는 $0^{\circ}C$가 적합하며(91%), 60일 냉장에는 2.5$^{\circ}C$가 적합하였다.(61%) 3. 이상의 결과로부터 다화성 누에의 품종보존을 위해서는 산란 후 2일 경과한 누에씨를 2.5$^{\circ}C$에서 50-60일간 냉장함으로서 연중계대동육회수를 반감시킬 수 있음이 밝혀졌다.

• 대한수의학회지
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• 제33권2호
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• pp.277-283
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• 1993

In the present study, observations were made on the life-history of Lymnaea viridis under laboratory conditions, involving incubation period of the eggs and their hatching rate, shell length of the newly hatched snails, sexual maturity, size of the snails when the snail produced the first egg-mass, the number of eggs in each egg-mass, egg-laying, ovipostion, growth rate of the snails, and longevity of the snail. At temperatures between $19.8^{\circ}C$ to $22.5^{\circ}C$, incubation period of the eggs occupied 10~12 days, and after beginning of hatching, all young snails emerged completely from the egg-mass within 5 days. The hatching rate was 88%. The average shell length of the newly hatched snails was about 0.064cm. The rate of growth was extraordinarily rapid under good laboratory conditions. When two snails were reared in one culture vessel($20{\times}15{\times}5cm$) with blue-green algae at about $22^{\circ}C$, snail growth was optimal, taking 37 days to reach 1.2cm in shell length. Sexual maturity reached in about 19 days. The size of the snails at sexual maturity was $0.78{\pm}0.05cm$ in length and $0.47{\pm}0.04cm$ in width. The first egg-masses produced were $0.59{\pm}0.22cm$ in length and $0.34{\pm}0.08cm$ in width, and contained 7~38 eggs. The eggs are usually laid in water. The egg-laying was affected by food and temperature. Snails fed with blue-green algae at about $22^{\circ}C$ produced larger egg-masses than the snails fed with fish food at about $26^{\circ}C$. Under conditions of continuous activity and growth, the maximum expectation of life appears to be 109~350(mean 230) days. And the shell length of snails at death were 1.39~1.64cm.

• 한국응용곤충학회지
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• 제43권2호
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• pp.135-141
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• 2004

본 연구에서는 왕사슴벌레의 국내 분포지가 재검토되고 이들의 대량사육기술 개발을 위한 생태적 특성이 조사되었다. 산란수를 최대화하기 위해서는 우화 후6개월이 지난 암, 수 성충에게 2주 이상의 교미기간이 허용되어야 하며 성비는 암：수 = 2：1이 이상적이었다. 산란수는 암컷 한 마리 당 최대 27.3개이고 알은 한 개씩 산란된다. 산란전기간은 평균 147.3일, 산란기간은 최소 120일 이었으며 난기간은 평균 15.6일이었다. 산란상은 직경 15cm${\times}$길이 15cm인 산란목이 3-4개 들어 있는 55${\times}$40${\times}$35cm크기의 산란상이 이상적이었다. 산란목으로는 상수리나무가 선호되었다. 사육실조건($25^{\circ}C$, 75% R.H., 16L：8D)에서 1령기간은 24.1일,2령은 29.8일, 3령에는 131.2일이 소요되었으며 용기간은 28.9일이 소요되었다. 성충수명은 35개월 이상이었다. 산란수를 증가시키기 위해서는 최소 3-4개월의 휴면기간이 필요한 것으로 밝혀졌다.

• 한국응용곤충학회지
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• 제50권1호
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• pp.55-63
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• 2011

본 연구는 감귤에 발생하는 해충인 네눈쑥가지나방의 실내 사육용 인공사료를 개발하고자 수행하였다. 인공사료의 주 재료로 옥수수와 메주콩을 조합한 사료에서만 정상적으로 발육하였으며, 옥수수와 메주콩의 전체 함량이 높은 사료에서 유충 생존성이 높았다. 효모와 콜레스테롤을 인공사료에 첨가하였을 때, 유충 발육기간은 짧아지고, 생존율은 높은 것으로 나타났다. 발육기간, 누적 생존율, 산란량에 차이는 인공사료와 감귤 잎을 먹은 개체들 간에 없었다. 최종적으로 네눈쑥가지나방 사육에 최적인 인공사료 조성은 물 1 L당 한천 25 g, 옥수수 100 g, 메주콩 100 g, 효모 30 g, 콜레스테롤 0.5 g, 비타민혼합물(Vanderzant vitamin mix.) 2 g, 염혼합물(Wesson's salt mix.) 2 g, 소르브산 2 g, 메틸파라벤(methyl-4-hydroxybenzoate) 2.5 g, 아스코르브산 2 g이었다. 사육법으로 유충은 플라스틱 원형용기(${\varphi}90{\times}40$ mm) 안에서, 갓 부화 유충부터 4령까지는 40마리씩 집단으로, 5령과 6령은 개체별 사육하였다. 성충들에는 10% 설탕물을 먹이로 하여 플라스틱 상자 안($25{\times}25{\times}25$ cm)에서 암컷 3마리와 수컷 5~6마리가 교미하도록 했고, 난괴는 거즈(눈 크기 1 mm)를 붙인 기름종이에 받았다. 기타 인공사료로 사육한 네눈쑥가지나방의 발육단계별 형태적 특징에 대하여 기술하였다.