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Somen Singh L.,Regional Tasar Research Station | Debaraj Y.,Regional Sericultural Research Station | Ibotombi Singh N.,Conal Muga Eri Research and Training Institute | Ray B.C.,Zonal Silkwork Seed Organisation | Singh R.,Silkworm Seed Technology Laboratory
Indian Journal of Sericulture | Year: 2012

Six breeds of the eri silkworm, Samia ricini Donovan viz., Yellow Plain (YP), Greenish Blue Plain (GBP), Yellow Zebra (YZ), Greenish Blue Zebra (GBZ), Yellow Spotted (YS) and Greenish Blue Spotted (GBS) were subjected to estimate their general combining ability in breeds and specific combining ability in the hybrids crossed in a 6 x 6 diallel fashion. The analysis of variance for combining ability of nine yield contributing traits manifested significant GCA variances in all the traits except absolute silk yield, while significant SCA variances were observed in seven parameters. Significant reciprocal variances were observed in all the nine parameters which were the indication of maternal effects in these traits in eri . silkworm. Among the six breeds, Yellow Zebra was found to be the best general combiner which exhibited significant effects in seven traits followed by Yellow Plain for six traits and Greenish Blue Zebra in five traits. Among the hybrids, YP x GBZ and YZ x GBS showed significant SCA effects for six traits. Observations on reciprocal crosses revealed significant effects by GBZ x GBP in seven traits. The hybrids YP x GBZ and GBZ x GBP have been identified for further trial rearing for higher production of eri silk. Importance of this study has been discussed in the paper. Source

Mishra P.K.,Research Extension Center | Sharan S.K.,Regional Tasar Research Station | Kumar R.,Central Tasar Research and Training Institute | Sinha M.K.,Central Tasar Research and Training Institute | Jaishankar C.,Central Tasar Research and Training Institute
Journal of Advanced Zoology | Year: 2013

Daba bivoltine ecorace of tropical tasar silkworm Antheraea mytitta is commercially exploited in tropical India for production of tasar silk. Its Daba bivoltine ecorace remains under facultative pupal diapause for 210-225 days. Diapause sets in this economically important insect up to 60 days. Its true or refractory period of diapause has been worked out to be 60-180 days when pupae are very less responsive to external stimuli. Its termination period of diapause has been worked out to be beyond 180 days. In the present study, an attempt has been made to see the impact of low temperature treatment on the pupae of diapause termination period on adult emergence pattern, diapause period and other grainage parameters. The diapausing pupae of 180,190,200 and 210 days age were given temperature treatment of 10,15,20 and 25°C. Among 180 days old pupae treated at 10°C, prolongation and scattered moth emergence over a period of 38 days was observed. Among the same lot pupae treated at 15°C, moth emergence was also observed to be scattered but with little reduced emergence span (34 days). Similar responses were also observed among 190 days old pupae. Among 200 and 210 days old pupae kept at 15°C, the emergence of moths was delayed with comparatively less peak period of emergence in comparison with control. The overall emergence was postponed up to three weeks without adverse impact on main grainage parameters. Summarily, it can be said that the diapause pupae which were in more advanced stage of pupal-adult development during termination period of diapause (195-205 days) in Daba BV were more sensitive to temperature at 15 & 20°C. Source

Singhvi N.R.,Regional Tasar Research Station
Plant Archives | Year: 2014

Tasar sericulture, the production of tasar silk, is an agro-based enterprise. Its major production phase consists of two biological processes of growing/maintaining Tasar food plants and carrying out rearing of Tasar silkworm, Antheraea mylitta D. Asan, Terminalia tomentosa W & A, is one of the primary food plants. The silk quality and quantity produced by Tasar silkworm depend upon nutritional value of their food plants. With introduction of new technologies in past few years' production and productivity levels in Tasar sericulture has gone up substantially. However, it is rare that fertilizers and manures are supplied to soil by the Tasar Sericulturists, as the Tasar silkworm rearing is done outdoor on natural forest plantation. This has led to exploitation of soils, thus affecting quality and quantity of produce. Present work was taken up to investigate the effect of soil application of vermicompost on leaf production and Tasar cocoon production. Study was carried out at field Khapa of RTRS Bhandara, during 2011-12, on existing natural plantation of T. tomentosa for three crops viz., I, II and III. Freshly prepared vermicompost was supplied to Asan plants @ 2.0 kg/plant. Soil application of vermicompost resulted in 9.75, 9.09 and 8.06% improvement in leaf yield over control during I, II and III crop period, respectively. Rearing of Tasar silkworms on treated plants, that were supplied with vermicompost, resulted in 17.17, 12.34 and 5.18% increase in cocoon yield over control, during I, II and III crop period, respectively. Larval weight was also more in case of treatment as compared to control, an indication of better leaf quality in treated plants. Single cocoon weight and single shell weight increased in case of cocoons harvested from vermicompost treated plants. In case of treatment SR% increased by 2.155% over control. Based on results of present study and it is recommended that vermicompost may be supplied to Tasar food plants in order to obtain good quality leaves and better produce. Source

Mahobia G.P.,Regional Tasar Research Station | Yadav G.S.,Regional Tasar Research Station | Singh B.M.K.,Central Tasar Research and Training Institute | Sinhadeo S.N.,Central Tasar Research and Training Institute | Vijayprakash N.B.,Seribiotcch Research Laboratory
Indian Journal of Sericulture | Year: 2010

'Rally' is an eeorace of tasar silk insect Antheraea mylittu D. (Saturniidae: Lepidoptera). endemic to Bastar plateau of Chhattisgarh, India. Il feeds primarily on the leaves of Sal (Shorea robustu Roxb.). The present study confers the correlations between the quantitative traits of male cocoons, female cocoons and traits in the sex pooled samples of cocoons collected from seven ecopockets of the habitats of Raily. The magnitude of association between the cocoon weight, shell weight, pupa weight, shell%, cocoon length, cocoon breadth, cocoon volume in the male cocoon, female cocoons and sex pooled samples of all seven ecopocket differs. The relation between cocoon weight and pupa weight exhibited higher degree of positive significant correlation (p<0.001). Increase in cocoon weight confers negative association with silk % in all the ecopockets, except Geedam, when sex pooled samples were computed for the association considering cocoon weight as independent variable and silk % as dependent variable. The magnitude of association varied between sexes, seasons and ecopockets can be considered as an effective parameter for selective breeding. Source

Sahay A.,Regional Tasar Research Station | Satpathy S.,Research Extension Center | Sharan S.K.,Regional Tasar Research Station
Indian Silk | Year: 2012

To help arrest the declining trend in tasar production in Odisha, seen in last few years, cluster-based project approach has been adopted to improve the production and productivity by ensuring support and technical guidance to the stakeholders. Creation of network, and interest among tasar farmers has helped them to work collectively with increased efficiency. Source

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