Assessment of cocoon characters of eri silkworm, Samia ricini Boisd. reared on Ailanthus species in different seasons

Eri silkworms were reared on two Ailanthus species viz., borpat (Ailanthus grandis Prain) and borkesseru (Ailanthus excelsa Roxb.) for evaluating the cocoon parameters in different seasons. Results indicated that the seasons and host plants had significant effect on cocoon parameters. The highest cocoon yield percentage was observed in the autumn season (84.22%) followed by spring (79.00%), early summer (71.67%) and late summer season (64.56%). Between the host plants, maximum cocoon yield percentage was observed in borpat leaves (77.33%). Autumn season and borpat leaves showed better performance in terms of cocoon weight (3.72 and 3.66 g, respectively), shell weight (0.43 and 0.43 g, respectively), pupal weight (3.28 and 3.22 g, respectively) and shell ratio percentage (11.64 and 11.67%, respectively), whereas early summer season and borkesseru leaves exhibited bottom values except the shell ratio percentage which was observed lowest in spring season (10.65%).