• 제목/요약/키워드: Silk moth

검색결과 46건 처리시간 0.032초

용기의 보호환경에 따른 불수정란(웅성불임잠)의 유발기구에 관한 조사연구 (Studies on the mechanism in the induced to unfertilized eggs(male sterility of Silkworm) by protected environment during pupae period)

  • 윤종관;오준식
    • 한국잠사곤충학회지
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    • 제15권2호
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    • pp.9-14
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    • 1973
  • 용기의 고온보호가 웅아의 생식력에 미치는 영향을 조사하기 위하여 9품종을 공시하여 유충기에는 각시험구 공히 보통육을 하고 화용후에는 일정기간을 고온(33$^{\circ}C$)에 보호하고 여기에 수원 103$\times$수원잠 104의 정상웅아를 교배하여 교미능력과 조사아수의 산하총란수에 대한 불수정비율 즉 웅성불임상황을 조사한 결과 다음과 같은 결과를 얻었다. 1) 용기의 고온보호는 상온에 비하여 웅아임의 불화가 현저히 나타나지만 그 출현율은 품종에 따라서 큰 차가 있다. 2)고온구는 상온구에 비하여 화아상태가 불량하다. 3) 교미능력은 수원잠계통에 비하여 모란 대동 일124 및 중108 등이 불량하다. 4) 외관상 수정능력이 있어 보이는 웅아도 이를 이용한 산하란의 수정상태를 보면 모란, 대동, 일124 및 중108 등에서는 65%내외의 불수정율을 나타냈다. 5) 용의 말기 1일간의 처리구에서는 10%내외의 불수정란율을 나타냈고 2일째 20%내외 3일째 35%내외 4일째 40~60% 5일째 68% 7일째 70%내외에 달하였다. 이러한 사실에 의하여 불임성의 출현양상은 용의 후기보다 큰영향이 미친다는 것을 알 수 있게 한다. 6) 고온처리 웅아와 교미시키고 5시간이 경과한 웅아에 대하여 그 교미낭과 수정낭내의 정자의 상태를 관찰한 결과 대조구에서는 생식계가 정상적이고 정자량이 풍부하며 운동력도 활발했지만 처리구에서는 정자량이 적고 운동력도 전자에 비하여 완만하였다. 7) 자아의 수정낭내의 정자의 상태를 관찰한바 고온구의 것은 상온구에 비하여 정자의 량과 운동이 약했으며 개체에 따라서는 발견할 수 없는 것도 있다. 8) 웅아교미기의 외부상태 및 교미기의 부속근육 등은 형태학적으로 아무런 이상이 없다. 9) 고온구의 용말기의 정소에서는 무핵정자의 상태까지 분화발달한 것이 거의 없고 대부분이 성숙분열에서 정자의 세포붕괴를 이르켜 퇴화하고 있지만 이 시기의 대조구에서는 이미 많은 무핵정자가 형성되고 있다.

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Microsporidian Disease of the Silkworm, Bombyx mori L. (Lepidoptera: Bombycidae)

  • Singh, Tribhuwan;Saratchandr, Beera
    • International Journal of Industrial Entomology and Biomaterials
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    • 제6권1호
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    • pp.1-9
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    • 2003
  • The silkworm, Bombyx mori, is prone to infection of various pathogenic organisms. Pebrine, one of the deadliest disease of silkworm caused by highly virulent parasitic microsporidian, Nosema bombycis has been understood since long. Infections of the disease range from chronic to highly virulent and can result in complete loss to the sericulture industry. Several strains and species of microsporidians have since been isolated from the infected silkworms; the disease is becoming increasingly more and more complex. Epizootiology, development of immunodiagnostic kit, use of chemotherapy and thermotherapy techniques has been addressed for identification and control of the disease. A technique of delayed mother moth examination, which plays a decisive role in the detection of the disease and harvestation of stable cocoon crop, has been described. An attempt has been made to review briefly the literature available on various aspects of the pebrine disease in order to develop efficient model(s) for the prevention and control of the disease and to suggest future avenues of investigation in the field of pebrine disease management.

Physiological and Biochemical Modulations during Oviposition and Egg laying in the Silkworm, Bombyx mori (L.)

  • Singh, Tribhuwan;Saratchandra, Beera;Raj, H.S.Phani
    • International Journal of Industrial Entomology and Biomaterials
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    • 제6권2호
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    • pp.115-123
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    • 2003
  • Oviposition and egg laying is an important physiological and behavioural event in the life cycle of the silkworm, Bombyx mori (L). Oviposition and egg laying is dependent on a number of intrinsic and extrinsic factors viz., neural, hormonal, environmental, physical, behavioral etc for the perpetuation of population. Although, the virgin female moths have fully developed embryos but active egg laying begins under the influence of mating which provides essential copulation stimulus for oviposition. After mating drastic biochemical changes occurred that incites egg laying under the influence of optimum environmental conditions. Weight of pupae as well as larval density has significant role on oviposition and egg laying behaviour in the silkworm wherein high pupal weight and inadequate rearing space affects not only the biology, morphology and physiology but also the oviposition and egg laying. Surface topography, plane of inclination, mating length, age of male moth, temperature and photoperiod etc has significant effect on reproductive physiology of silkworm. An attempt has been made in this review article to elucidate briefly the works carried out on mating behaviour, direct and indirect copulation stimulus, vitellogenesis, influence of environmental factors besides effect of weight of pupae and or pharate adult and larval density on oviposition and egg laying behavior in the silkworm, B. mori and its significance in silkworm seed production.

Composition and Diversity of Gut Bacteria Associated with the Eri Silk Moth, Samia ricini, (Lepidoptera: Saturniidae) as Revealed by Culture-Dependent and Metagenomics Analysis

  • MsangoSoko, Kondwani;Gandotra, Sakshi;Chandel, Rahul Kumar;Sharma, Kirti;Ramakrishinan, Balasubramanian;Subramanian, Sabtharishi
    • Journal of Microbiology and Biotechnology
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    • 제30권9호
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    • pp.1367-1378
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    • 2020
  • The polyphagous eri silk moth, Samia ricini, is associated with various symbiotic gut bacteria believed to provide several benefits to the host. The larvae of S. ricini were subjected to isolation of gut bacteria using culture-dependent 16S rRNA generic characterization, metagenomics analysis and qualitative enzymatic assays. Sixty culturable aerobic gut bacterial isolates comprising Firmicutes (54%) and Proteobacteria (46%); and twelve culturable facultative anaerobic bacteria comprising Proteobacteria (92%) and Firmicutes (8%) were identified inhabiting the gut of S. ricini. The results of metagenomics analysis revealed the presence of a diverse community of both culturable and un-culturable gut bacteria belonging to Proteobacteria (60%) and Firmicutes (20%) associated with seven orders. An analysis of the results of culturable isolation indicates that these bacterial isolates inhabited all the three compartments of the gut. Investigation on persistence of bacteria coupled with metagenomics analysis of the fifth instar suggested that bacteria persist in the gut across the different instar stages. In addition, enzymatic assays indicated that 48 and 75% of culturable aerobic, and 75% of anaerobic gut bacterial isolates had cellulolytic, lipolytic and nitrate reductase activities, thus suggesting that they may be involved in food digestion and nutritional provision to the host. These bacterial isolates may be good sources for profiling novel genes and biomolecules for biotechnological application.