Life cycle of silkworm (Bombyx mori Linnaeus ):

• Silkworm is holometabolous in nature and is univoltine, bivoltine and multivoltine in nature.
• The life cycle of silkworm shows the following stages:

a) Egg

• Female adult lays about 400-500 eggs called silk seed in clusters on the surface of mulberry leaf or artificially prepared butter cups.
• Eggs are oval, small an creamy white colored.
• They turn black while hatching in 9-11 days.

b) Larva

• Newly hatched larva are black or dark in color.
• They turn light and smooth during further succeeding instar.
• 5 larval instar are present of which the first 3 are known as young worms and other 2 instar are called as grown up worms.
• In last instar stage , they start secreting silken thread and cover themselves .
• This stage last for 18-24 days.

c) Pupa

• Pupa stick together by serichin or silk gum forming a continuous fiber of about 500 mm long.
• Cocoon is oval in shape and white or yellow in color.

d) Adults

• Adults come out by making holes through cocoon.
• Adult are creamy white with female bigger than male.
• They mate immediately after emergence, give up food and survive only for 2-3 days.