Effect of mating duration and the number of females/male moth of Bombyx mori L. on eggs fertility

The present work was carried out to investigate eggs fertility of Bombyx mori L. as affected by mating duration and male fertility and their ability of mating more than once of silkworm. Monovoltine hybrid imported race of B. mori L. was obtained from Sericulture Research Department, Agriculture Research Centre, Ministry of Agriculture in form of eggs and reared under laboratory conditions of 25± 3℃, 72 ± 2% R.H. and 15:9 daily L:D and the emergence moths were used for the mating experiment. The obtained results showed that the minimum duration of mating to produce fertility eggs higher than 95% was ½ h and the least fertility rate of eggs was produced when the mating duration was less than ½ h. The average highest number of females for mating with the same male is 20.8 females, the average number of females that laid fertilized eggs at a higher rate of 90% is 13.8 female, the average number of females that laid fertilized eggs at a lower rate of 90% is 2.6 female while the average number of mated (4.4 females) females laid unfertilized eggs.