The life cycle of silkworm (Bombyx mori Linnaeus ):

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

a) Egg

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

b) Larva

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

c) Pupa

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

d) Adults

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