Production parameters and yarn realization in eri silkworm Samia ricini as influenced by alternative host plants Kakati L. N.*, Merenjungla Department of Zoology, Nagaland University, Hqs. Lumami, P.O. Lumami, 798627, Nagaland *Corresponding author Email: kakati_ln@yahoo.com
Online published on 13 March, 2018. Abstract Nagaland is a traditional state for ericulture, mostly practiced on the primary food plant Ricinus communis L., the castor for rearing of Samia ricini Donavans. However, this host is not sufficiently available during the dry season, for continuous rearing. Hence, the eri farmers use certain alternative food plants namely Heteropanax fragrans Seem (kesseru), Manihot utilissima Phol (tapioca) and Evodia fraxinifolia Hook (payam), of which the latter two plants are abundant in Nagaland. The present study evaluated during spring, summer and rainy seasons, and assessed the suitability of alternative food plants particularly tapioca and payam along with primary food plant for cocoon production and silk yield. The study revealed the impact of seasons on the larval duration which was minimum in castor (12.00± 1.13 to 17.67± 1.51 days) and maximum in payam (20.67± 0.97 to 25.33± 1.79 days). The seasonal mean cocoon dimension and weight ranged from 16.96± 0.33 to 21.62± 0.34 cm2 and 2.91± 0.50 to 3.93±0.57 gm, respectively in the four food plants. The important characteristics like shell weight, silk ratio (%), empty cocoon weight (gm), yarn weight (gm), yarn realization (%), degumming loss (%) and waste (%) with tapioca and payam fed cocoons were comparable with that of castor and kesseru. While castor showed supremacy over others, the present study indicates the commercial prospects of tapioca and payam as alternative food plants, particularly during off season for sustainable rearing of Samia ricini in Nagaland. Top Keywords Samia ricini, Nagaland, alternative food plants, payam, tapioca, kesseru, larval duration, shell weight, silk ratio, empty coccomn weight, yarn weight, yarn realization, degumming loss, waste. Top |