Potency of bivoltine male moths of pure silkworm breed and hybrid in laying preparation.

摘要

The present study is an attempt to evaluate the comparative potentiality of bivoltine male moths of pure breed NB4D2 and hybrid (SK6 x SK7) in production of Nistari x NB4D2 a popular Multi x Bivolltine silkworm hybrid in West Bengal state of India and Nistari x (SK6 x SK7) which is yet to be popularized in Eastern and North Eastern parts in India. Rearing of P1 layings, Nistari, Bombyx mori L. - an indigenous multivoltine silkworm breed was conducted at seed farmers' level in 2 villages during 3 crop seasons viz. Autumn (September-October), Winter (December-January) and Spring (February-March) in 2 consecutive years under microclimatic conditions. Production of hybrid commercial layings was also conducted in 2 consecutive years in commercial grainage under microclimatic conditions in above mentioned three seasons. In grainage pairing efficiency percentage, pair to and laying percentage, recovery of laying in g/kg. of Nistari seed cocoon and fertility percentage were recorded beside microclimatic parameters i.e. temperature and relative humidity in grainage rooms. The results revealed that grainage performance in respect of pairing efficiency (cocoon to pair percentage), pair to laying percentage, recovery of laying per kg Nistari seed cocoon and fertility percentage were higher in all the three seasons in both the years in case of crossing of Nistari female moths with hybrid bivoltine male moths (SK6 x SK7) during hybrid df1s production.