Identification of promising castor genotypes for rearing Eri silkworm, Samia cynthia ricini
A study was undertaken to evaluate the different castor genotypes for their suitability in eri silkworm rearing. Seven castor genotypes along with control (mixed leaf) were evaluated by providing leaves of these genotypes throughout the larval stage. Eri silkworms nourished with leaves of PCH-111 genotypes registered significantly higher leafconsumption during 1V, V instars and during total larval period (226. 8, 1526.3 and 1786.8 g/50 larvae respectively). While it was lower in control during V and total offive instars (1332.1 and 1562.9 g/50 larvae respectively). Similarly, PCH-ll1 genotype recorded highest food digestion (1094.2g) along with PCH-222 (1131.0g), GCH-4 (1059.5g) and Haritha (1025.5g) during the total larval period. The amount offood converted to body matter was more with PCH-111 (572.2g) and GCH-4 (552.5g/50 larvae) during V instar. The mean consumption index was more with PCH-111 (1.3g)followed by GCH-4 (0.9g), Haritha (0.9g) and PCH-222 (0.9g) in the larval period. The fifth instar worms nourished with the leaves of PCH-111 (65.0g) and GCH-4 (67.0g) recorded significantly higher approximate digestibility.