EFFECT OF SEASON ON GROWTH, SURVIVAL RATE AND PROTEIN LEVEL OF SELECTED RACES OF THE SILKWORM, BOMBYX MORI L. IN NAGPUR REGION.

The seasonal effect on growth, survival, and protein content in haemolymph, fat body, and silk gland of the silkworm, Bombyx mori L. hybrid races viz. PM x CSR2, CSR4 x CSR2 and CSR2 x CSR4 using mulberry variety Kanva-2/M5 during rainy, winter and summer seasons have been investigated. The protein level in the haemolymph, fat body, and silk gland was higher in PM x CSR2 during the winter season followed by CSR4 x CSR2 and CSR2 x CSR4. During the summer season, the protein content in all the tissues was low. The protein content was high in winter due to the slow rate of development and growth of the silkworms, which allowed larvae to consume more food and convert the food into protein due to extended larval duration, resulting in improved cocoon characters. The changes in the protein concentration of haemolymph, fat body, and silk gland are correlated with the degree of food absorption, and conversion and utilization during the different seasons. The season has played a significant role in increasing the activity of proteins level in haemolymph, fat body and silk gland. The growth and development of silkworms and mortality rate are also influenced by season. A significantly highest weight of 3.005±0.68 g was recorded in PM x CSR2 during the winter season when compared with other races and seasons. Results showed CSR4xCSR2 and CSR2xCSR4 breeds are more susceptible in all seasons with a high rate of mortality with 10 % and 12 % in the summer season has been recorded. [ABSTRACT FROM AUTHOR]