Effects of various environment conditions on the performance of silkworm (Bombyx mori L.)

Different responses of silkworm larvae under various rearing climate condition would help to obtain better economic performance of some silkworm varities in specific climate conditions. The effect of 4 rearing climate conditions including 1) standard 2) high temperature and humidity, 3) high temperature and low humidity and 4) temperature fluctuation were investigated on the performances of six different silkworm hybrids including 151×152, 151×110-32, 151×154,103×104, 31×32 and 107×110. All hybrids showed better performances for larval, pupa and total vitality under standard conditions compared with the other rearing environments. There was no significant difference for the good cocoon percentage between the hybrids of 151×152, 151×154 and 107×110 under standard temperature fluctuating and warm/dry climate condition. The hybrid of 151×110-32 at standard condition and the hybrids of 103×104 and 31×32 at standard and warm/dry conditions produced higher values of good cocoons. For all hybrids, the larval mortality increased by growth of temperature and humidity. Meanwhile the pupal mortality rose with increasing of temperature either in dry or humid condition. The highest productivity (weight of total and good cocoon per 10000 larvae) within all treated hybrids obtained under standard and temperature fluctuation of temperature left no adverse effect on single cocoon weight for hybrids of 151×110-32, 31×32 and 107×110, while significantly increased the cocoon weight for hybrid of 103×104. The obtained results provide high temperature and humidity, high temperature and low humidity, and temperature fluctuation decreased production level. Furthermore, 103×104 hybrid is suitable for regions with temperature fluctuation. Also 103×104 and 31×32 hybrids are suitable for regions with high temperature and humidity, and high temperature and low humidity.