The Indian Eri Silkworm, Philosamia ricini H. (Lepidoptera: Saturniidae) has several isolated
populations, geographically separated (ecoraces) in the states of Assam and Meghalaya. Three of
them are commercially exploited for the production of eri silk in North Eastern States. Eri DFLs
(Disease Free Layings) supplied to the farmers of Odisha are of a mixed variety of unknown
origin. It has a very low yield rate, making the Eri farming not so lucrative. Hence attempts was
made for rearing three varieties of ecoraces of Eri collected from the North East and assess the
seasonal variations in their performances in the School of Life Sciences, Sambalpur University,
Burla. It was observed that commercial productivity and reproductive parameters were influenced
by the seasonal variations of the rearing environment. Values of productivity parameters like
cocoon weight, shell weight, shell ratio percentage and total silk production were found to be
highest in winter followed by spring, autumn and rainy seasons while the lowest values were
recorded in the summer crop. The two- way analysis of variance (pd” 0.05) showed significant
difference in rearing parameters among the different ecoraces of Eri silkworm in different seasons.
Among the varieties, the rearing efficiency and silk ratio of Borduar ecorace was found to be the
highest in comparison to others. The seasonal rearing efficiency showed an increasing trend from
summer to winter season as regards commercial productivity was concerned.