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The study traces the correlation between tissue- based carbohydrate levels and economic traits of the
silkworm, Bombyx mori, both under normal and zinc-fed conditions during fifth instar development. The
growth trends of carbohydrates in silk gland (SG), fat body (FB), haemolymph (HL) and segmental
muscle (SM) indicate that the total carbohydrates tend to accumulate in remarkable proportions (~814%)
in SG and maintain a constant rate of influx in FB, HL and SM. In terms of their rate of accumulation, the
SG recorded a higher compound periodical growth rate (CPGR) of 41.82%, followed by SM (40.54%),
FB (27.24%) and HL (9.17%). When, the silkworm larvae were fed with zinc chloride-enriched mulberry
leaves, the rate of accumulation of carbohydrates increased remarkably (CPGR:46.61%) in SG, but a
constant steady trend, as observed in the control batches, was maintained in the other three tissues.
While carbohydrate levels constitute the chief energy reserves for metabolism and silk production, the
economic parameters of both cocoon and silk (silk yield, shell weight, floss weight, floss-shell ratio, flosssilk
ratio, raw silk weight, renditta and denier) were significantly modulated under the influence of zinc
salt.
Key words: Bombyx mori, Carbohydrates, Economic parameters, Zinc chloride.