• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.124-129
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• 1996

Oral application of dimethyl sulfoxide in different concentration (1, 3 and 5 percent) to silkworm, Bomyx mori at the fourth and the fifth instar has significantly increased the commercial characters such as larval and silkgland weights, female and male cocoon weights, their shell weights and egg production. However, larval duration, cocooning and hatching percentages did not showed any significant change, as compared with that of the corresponding parameters of the carrier control. Similarly the glycogen and protein contents of the fat body and trehalose and protein contents of the haemolymph were significantly increased in 1 and 3 percent, whereas the increase of them in 5 percent concentration did not take place significantly, except haemolymph trehalose where it was found to be significant, as compared with that of carrier control.

• Journal of Sericultural and Entomological Science
• /
• v.38 no.2
• /
• pp.130-137
• /
• 1996

Effect of topical application with 5, 10 and 15${\mu}$g/ml thyroxine on the pre-cocoon, cocoon, postcocoon and silk improvement were studied in bivoltine silkworm NB18 breed of B. mori L. Thyroxine was applied independently on alternate days to silkworm of IV and V instar larvae. The treatment of all different concentrations resulted in a significant increase in commercial characters like larval weight, silkgland weight, cocooning percentage, female cocoon weight and its shell weight and male cocoon shell weight and its ratio, cocoon dimension, length of the filament and its weight and oviposition. However, there was no significant change in larvel weight in 5${\mu}$g/ml treated group and larval duration was significantly decrease. But moth emergence percentage and hatching percentage did not show any significant change when compared with that of carrier control.