Ecology, Environment and Conservation Paper

STUDIES OF PRESERVATION OF BIVOLTINE MALE MOTHS AT LOW TEMPERATURE ON SURVIBILITY AND REPRODUCTIVE PARAMETERS IN SILKWORM, BOMBYX MORIL.

L.M. SAHA, S. Chanda, J.S. Ngalangam and B.B. Bindroo

Abstract

Effective production of Multi x Bi layings depends on synchronization of emergence of multivoltine and bivoltine moths. In the present study an attempt has been made to provide information on the effect of preservation of bivoltine pure, i.e. NB4D2 and hybrid male moths of (SK6 x SK7) and (B.Con.1 x B.Con.4) at 10±2 o C after 2, 4, 6, 8 and 10 days of cold storage on their survibility and reproductive parameters when they mated with the multivoltine virgin females of two breeds – Nistari and M.Con.4. Cold stress on the bivoltine male moths The cold treated male moths of the bivoltine breeds showed an adverse effect on survibility, pairing efficiency, pair to laying recovery, recovery per kg. multivoltine seed cocoon and hatching percentage of layings with increased duration of cold treatment. All the results on survibility and reproductive parameters are the pooled data of three seasons which are highly significant (P<0.01) among all the treatments and combinations. The effect of cold was more pronounced in bivoltine pure breed than hybrids in all parameters. Further, it is revealed from the experiment that potency of bivoltine male moths also depends on multivoltine female partners during cross breed laying preparation. The performance of M.Con.4 as a female partner was significantly better (P<0.01) than Nistari. The observations suggest that in case of exigencies male moths can be cold stored at 10±2 o C upto 4 days and effectively utilized for preparation of cross breed layings without having deleterious effect on survibility and reproductive parameters.