Rearing performance of Eri silkworm Philosamia ricini Hutt. on different castor varieties grown under vidarbha region

A.D. Jadhav*
Department of Zoology, Shivaji University, Kolhapur-416 004,
Maharashtra, India

Received 5th January, 2012; Revised 16th February, 2012

Abstract : Castor (Ricinus communis L.), the primary food plant of eri silkworm Philosamia ricini is cultivated in Maharashtra in about 25,000 hectares of land mainly in Vidarbha & Marathawada region for its non-edible oil seed production purpose. Various studies indicated that upto 30% of leaves can be harvested from castor plants for rearing of eri silkworm without  affecting the yield of castor seed. Efforts are being made by State Government & Central Silk Board to introduce sericulture as a profitable farm enterprise in Maharashtra under the concept of integrated farming system. In Vidarbha region of the state cotton, soyabean & orange are the cash crops however, now days sericulture is also a subsidiary farming system for improving socioeconomical condition of many farmers of this region. Ericulture will be a boon for small farmers to enhance their income from castor. An experiment has been conducted at Dhabha Jamani Govt. silk farm located in Bhandara district during 2010-2011 to evaluate some castor varieties for rearing of eri silkworm viz. GCH-4, Local Red and Local green by package of practices for castor  the four rearing technology. In the study, it was observed that castor variety has effect on rearing performance of eri silkworm. Significant variation was observed in larval weight, larval duration,(ERR) Effective rate of rearing shell weight, cocoon weight and shell percentage among the various castor varieties. In all the rearing parameters local green variety has shown better performance. However, larval duration was reduced by about 20 hours when fed with local green variety. The rearing batches fed on local green variety recorded ERR OF 9386, whereas it was 8675 and 8291 respectively with Local Red and GCH-4 varieties. It is also observed that there was marked improvement in cocoon weight, shell weight and shell percentage when feed with Local Green variety prevalent in Vidarbha region. Shell percentage was 13.89, 12.56 and 12.64 respectively in Local Green, Local Red and GCH-4 castor varieties. Significant difference was also observed with respect to fecundity. The study indicates that there is scope for further expansion of Ericulture to improve socioeconomic condition of Viderbha farmers by judicious use of castor plantation for eri cocoon production & popularization of ericulture.