Morphological Variation of Antheraea assamensis Helfer upon Semi-domestication: A Study on Rearing, Disease Incidence and Seed Production Performance

Abstract

Muga silkworm is multivoltine and primarily feeds on two primary food plants Som (Persea bombycina King. syn. Machilus bombycina) and Soalu (Litsea polyantha Kost. syn. Litsea monopetala). Muga silkworm Antheraea assamensis (n=15) is a semi-domesticated silk moth mentioned in literature as early 1662 BC. In its annual life cycle there are six crops of cultivated muga silk worm whose nomenclature is based on the local Assamese names of month. By virtue of the narrow ecological distribution of host food plant Antheraea assamensis is confined to only Assam and North East state of India. Empirical observations show that the population is declining due to depletion of natural habitat and lack of genetic variability among population. The wild muga silkworm which is tri or tetra voltine in nature is also found nearby forest area of human habitat in different host plant in N E state of India. A stock of wild muga silkworm collected from the nearby area of Nongpoh and Mendipathar Meghalaya. reared and maintained in muga farm and grainage activities of both wild and cultivated muga were conducted for comparative study. Details of morphology, economic characters and disease occurrence of wild and cultivated muga was studied for future improvement and breed development and also for future strategy of muga silkworm. The morphology of wild muga silkworm are little variant than cultivated muga and economic characters i.e. fecundity of wild muga was recorded 220 - 227 nos. in against the fecundity of cultivated muga observed 120-170 nos. and one gram total numbers of egg contain 120 -135 nos in wild muga in against 134 -145 nos.in cultivated muga. Average cocoon weight wild muga cocoon is ♂= 5.80 g & ♀= 6.60 g in against average cocoon weight ♂= 5.10 g & ♀= 5.54 g in cultivated muga silkworm. Average shell weight ♂= 0.51 g & ♀= 0.60 g in wild muga silkworm and average shell weight ♂= 0.43 g & ♀= 0.51 g in cultivated muga silkworm were recorded. Study revealed that the fecundity, weight of eggs, cocoon weight and shell weight are higher in wild muga silkworm than cultivated muga silkworm. Thereafter it is found that only protozoon disease was reported in wild muga silkworm and other disease i.e. Flacherie, Grasserie, Muscardine was not reported in wild muga silkworm. The mono race muga have no high yielding breed or hybrid and hence breeding programme between wild and cultivated muga may be carried out to get more heterosis, vigourity and yield enhancement.