STUDIES ON COCOON SIZE VARIABILITY IN MULTIVOLTINE X BIVOLTINE HYBRIDS OF THE SILKWORM, BOMBYX MORI L. TOLERANT TO HIGH TEMPERATURE AND HUMIDITY
K. UMADEVI *
CENTRAL SERICULTURAL RESEARCH AND TRAINING INSTITUTE MYSORE-570 008, INDIA
D. RAGHAVENDRA RAO *
CENTRAL SERICULTURAL RESEARCH AND TRAINING INSTITUTE MYSORE-570 008, INDIA
*Author to whom correspondence should be addressed.
Abstract
In the present study an attempt has been made to evaluate Cocoon size variation in multivoltineX bivoltine hybrids comprising of fifteen oval X oval and fifteen oval X dumb- bell type silkworm hybrids. Results indicated that six hybrids viz., UDK2 x CSR3, UDK3 x, CSR3, UDK4 x CSR2, UDK4 x CSR3. UDK3 X CSR17. UDK5 X CSR2 among oval X oval type and one hybrid viz., UDK1 X CSR16 among oval x dumb-bell type produced uniform cocoons showing standard deviation of cocoon length/width ratio less than eight. These hybrids can be commercially exploited for the production cf uniform silk.
Keywords: Bivoltine, oval, dumbbell, cocoon size, multivoltine