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Eri silkworm is multivoltine, polyphagous in habit feeding mainly on castor (Ricinus communis L.) for its growth and development towards successful cocoon production. In this regard, an attempt has been made to explore different ecotypes of castor available in wild form (perennial) in the Western Ghats region of Karnataka for rearing of eri silkworm. Altogether, 10 castor ecotypes were identified in five locations (Heggada Devana Kote, Madikeri, Sakaleshpur, Shimoga and Sirsi) of Western Ghats of Karnataka and two from Mysore location (for comparison) through molecular characterization (DNA sequencing) and accession numbers were obtained from the National Centre for Biotechnological Information (NCBI). The identified castor ecotypes were grown and leaves were utilized to assess the rearing performance using three strains of eri silkworm (Yellow-Plain, Blue-Plain and Blue-Zebra). The results of the investigation revealed that, the Yellow-Plain strain of eri silkworm fed on leaves of the castor ecotype bearing accession No. KJ000406 recoded significantly superior matured larval weight, total larval duration, cocoon weight, shell weight, cocoon yield, shell yield, shell ratio, silk productivity, fibroin and sericin. Further, the castor ecotypes possessing accession numbers KJ000404, KJ130043, KJ130045, KJ000402, KJ300047, KJ000407, KJ000405, KJ130044, KJ130046 and KJ000403 were found next best in respect of all the rearing parameters. However, Blue-Zebra strain of eri silkworms fed on the leaves of castor ecotype possessing accession No. KJ130048 recorded least rearing parameters.

Key words: Eri silkworm, Samia cynthia ricini, castor, Ricinus communis, Western Ghats.