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What Do Silkworm Moths Eat?

After silkworm moths emerge from their cocoon, they live just for 2 to 3 days. The moths do not eat anything during this time. After mating, the female lays around 300 to 500 eggs and dies.

Although silkworm moths are originally from China, they are found throughout the world today. The moths are domesticated to such an extent that they can no longer survive in the wild and do not have the ability to fly. Silkworm moths are commercially important as the cocoons are a source of silk.

Silkworm Moth Eggs
- The eggs are yellow in color when laid, but change to gray or purple after about a week. They hatch within three weeks. The eggs need warmth during spring to hatch, and if laid during summer or early fall, they do not hatch until the following spring.
Silkworm Larvae
- Silkworm larvae are hairy in appearance and measure around 3 mm long. Unlike silkworm moths, the larvae are voracious eaters and subsist on young, tender mulberry leaves during the initial few days. As the larvae grow, they begin eating tougher leaves. By the time the larvae are ready to pupate, they eat any type of leaf on the mulberry tree.
Molting
- The larvae have five molts during which they shed their skin as they grow in size. These growth stages are called instars. In the first stage, the larvae lose their hairy appearance and thereafter they have soft and smooth skin for the rest of their lives. The larvae grow quite fast and become as big as a human's ring finger.
Silkworm Pupae
- When the larvae are ready to pupate, they stop feeding and look for a place on the mulberry tree to form white or yellow cocoons around their bodies. The larvae encased in the cocoons shrink in size and develop a hard exterior. The pupal stage lasts for around 2 to 3 weeks. The cocoons break open and adult moths emerge, completing the metamorphoses.
Adult Silkworm Moths
- Adult silkworm moths have fat bodies and creamy white wings. They have a wingspan of around 2 inches, which is rather small, and thick bristles on the body. Although the moths can beat their wings rapidly, they cannot fly.
  
  The male and female moths are slightly different. The females have large abdomens, while males have long rake-like antennae.
Silk Harvesting
- The cocoon that a silkworm larva spins around its body is made of a single, continuous thread. The thread is a type of protein from the salivary glands in the head. After the cocoon is formed, it is immersed in boiling water. This kills the pupa and facilitates easy unraveling of the silk thread. The length of a single silk thread from one cocoon is around 400 to 1,000 yards in length.

Insects & Science