Comparative performance of Silkworm (Bombyx mori L.) Hybrids
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Date
2003
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SKUAST Kashmir
Abstract
Bombyx mori L. a holometabolus lepidopteran insect is a domesticated silk worm and has been in use since the dawn of human civilization as a source of silkfibre for producing exquisite textiles and dress materials. The adaptibilities to environmental stress of Bombyx mori L. are different from those of wild insects and the (rearing technique) varies to suit the requirements under different ecological conditions.
Increase in productivity lies in rearing more viable and productive silkworm breeds and a matching technique to rear them successfully. There is a high correlation between assimilation and physiology of silkworm and in recent past there has been increased awareness regarding the nutritional demands of silkworms during rearing. Mulberry leaf is the exclusive food of silkworm Bombyx mori L. and it is natural that its quantity and quality in rearing decides the success of crop. Although many mulberry varieties are available in different sericulture countries only a few are popular for commercial exploitation. The quality of mulberry leaf has a great influence on the amount ingested by silkworm Bombyx mori L. In the present investigation the amount of food was calculated from quantity of mulberry leaves fed to the silkworms less the quantity of remained leaves, the amount of food digested was calculated from the quantity thus obtained less the quantity of excreta. The digested food was calculated in percentage of the total food ingested. For the present investigation four silkworm hybrids namely , NB4D2SH6, SKAU-R-1 SKAU-R-6, CSR2 CSR4 and CSR2 CSR5 were evaluated for their efficiency of conversion of ingested and digested food into their body matter. In addition these hybrids were also analysed for qualitative as well as quantitative characters such as yeild/10,000 larvae by number, by weight (kg), single cocoon weight (g) single shell weight (g), shell ratio (%) and filament length (m) under the impact of single mulberry variety Ichinose to qualify them for rearing at commercial level.
Perusal of the results reveals that for ingesta NB4D2SH6 is at par with SKAU-R-1 SKAU-R-6 but significantly different from CSR hybrids. SKAU-R-1 SKAU-R-6 is at par with CSR2 CSR4 but significantly different from CSR2 CSR5. The CSR hybrids are at par with each other. For approximate digestibility CSR hybrids are at par to each. CSR2 CSR4 is at par with SKAU-R-1 SKAU-R-6 and NB4D2SH6 while as CSR2 CSR5 is significantly different than SKAU-R-1 SKAU-R-6 and NB4D2SH6. For faeces voided and growth rate CSR combinations are significantly different to that of SKAU-R hybrids and NB4D2SH6. For larval weight gain NB4D2SH6, SKAU-R-1 SKAU-R-6 and CSR2 CSR4 are at par. NB4D2SH6 and SKAU-R-1 SKAU-R-6 are significantly different than CSR2 CSR5 while as CSR2 CSR5 is in turn at par with CSR2 CSR4. From yield point of view, CSR combinations are at par with SKAU-R hybrids, however, they are significantly different from NB4D2SH6. Based on their performance with regard to their quantitative characters such as shell weight (g), shell ratio (%) and filament length (m), the CSR combinations are better than SKAU-R-1 SKAU-R-6 and NB4D2SH6.
Description
M.Sc Thesis submitted to SKUAST Kashmir
Keywords
Silkworm (Bombyx mori L.), Hybrids, Sericulture