Rearing performance of different eco-races of eri silkworm (Philosamia ricini) Donovan during summer season of Uttar Pradesh.

The rearing performance of four different eco-races of eri silkworm, Philosamia ricini was studied during 2007 and 2008 summer season. The rearing performance of Borduar, Titabar, Dhanubhanga and Mendipathar eco-races was analyzed based on their hatching %, larval duration (d), weight of full grown larvae (g), yield (by number and weight), single cocoon weight (g), shell weight (g), shell ratio (%), cocoon shape variability, pupal period (d), pupation rate (%), and leaf silk conversion rate (%). The Titabar eco-race of P. ricini showed better rearing performance compared to Borduar, Dhanubhanga and Mendipathar eco-races during summer rearing. The rearing parameters such as weight of full grown larvae, yield by number of larvae, yield by weight of larvae, single cocoon weight, shell weight, shell ratio, cocoon shape variability, pupation rate differed significantly among different eco races of eri silk worm.