Abstract:
An attempt was initiated for the utilization of different plant materials as food supplement for the improvement of different economic traits of Bombyx mori L. For this purpose initially an experiment was conducted to screen out different parts of Abroma Augusta, Centella asiatica, Neolamarckia cadamba, Solanum tuberosum, Persicaria acuminata and Andrographis paniculate plant with respect to their toxic effect on silkworm, Bombyx mori L. Relative toxicity by probity analysis for different parts of six plants extracts at different feeding schedules against silkworm larvae have been found out. Results on the mean mortality percentage of the larvae indicated that all the parts of P. acuminata and A. paniculata extracts showed toxic effect. With the increase of the dose of the extracts of the plant materials mortality of the larvae were increased. The LD50 values for different parts extracts at different feeding schedules also implied that different parts of those plant extracts produced higher mortality so that fruitful results could not be achieved with the supplementation in the feeding of silkworm larvae.
On the other hand, results on the mean mortality percentage of the larvae indicated that all the parts of A. Augusta, C. asiatica, N. cadamba, S. tuberosum plant extracts were not toxic. The LD50 values also reported the same effect.
After screening, the effects of the supplementation of different parts, viz. leaf, stem, root extracts of A. Augusta, C. asiatica, N. cadamba, S. tuberosum on growth and development of B. mori at different feeding schedules, viz. fed only in 1st feeding of 3rd to 5th instar larvae (FS-1), fed every day in 1st feeding of 3rd to 5th instar larvae (FS-2), fed every day in 1st and 3rd feeding of 3rd to 5th instar larvae (FS-3) were conducted.
Leaf extract of A. Augusta increased the WML, LML, BML at different doses compare to control while fed in FS-1, FS-2 and FS-3. The highest and the lowest results for these parameters were observed at 500 ppm and control respectively………………………………
Description:
This thesis is Submitted to the Department of Zoology, University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD)
