author(s)
Chaitra S, Prashanth J and Jagadeeshkumar TS

abstract
In the present study the amount of nitrogenous uric acid is found to be determined both in malpighian tubules and dry litter during fifth instar silkworm larvae. The PM X CSR₂ multi-bi hybrid and FC₂ X FC₁ bivoltine double hybrid silkworm revealed positive response and consistent increase in the level of production of uric acid. The pattern of formation of uric acid in malpighian tubules of both the hybrids exhibits consistent level of increase in all the days of fifth instar; however, the quantum of uric acid is relatively more on the last two days of fifth instar silkworm larvae. The level of changes in uric acid content is comparatively higher than the Malpighian tubules in all the days of V instar silkworm of both the hybrids. The expression and manifestation of both the quantitative and qualitative traits of PM X CSR₂ and FC₂ X FC₁ were recorded. The cocoon characters of FC₂ X FC₁ hybrid showed better in performance in the expression and manifestation compare to PM X CSR₂ hybrid in cocoon weight, shell weight and shell ratio pre-monsoon. The filament length and filament weight are the qualitative parameters also reflected on par with the cocoon characters. The thickness of the filament is predetermined and reflected the quality of the silk. In FC₂ X FC₁ the denier is lesser than the PM X CSR₂ which shows the denier is almost doubled. Finally, the quantum of cocoons required to produce one kg of raw silk is of almost 5.36kg whereas, the PM X CSR₂ showed 8.28kg for the production of one kg of raw silk. In the present empirical analysis in relation to the uric acid content in dry excrement and malpighian tubules during fifth instar are carried out to understand the day to day changes in the chief nitrogenous waste product of the silkworm, Bombyx mori L.