How Big Can Silkworms Grow? A Detailed Explanation of Silkworm Body Size

When raising silkworms, watching them grow from small to big is a very fulfilling thing, so how big can silkworms actually grow?

1. How Big Can Silkworms Grow

Silkworms can grow up to 6-7 cm long. Silkworms go through four molts, and each molt makes them grow a bit bigger. The number of molts is used to indicate the silkworm's age. Generally, silkworms that have molted four times can grow to 6-7 cm and are fifth-instar silkworms. Fifth-instar silkworms are about to start preparing to spin silk and cocoon.

2. Changes in Silkworms

Newly hatched ant silkworms are first-instar silkworms. They are rather fragile, entirely black, and can only eat relatively tender mulberry leaves. They are about 3-5 mm long. After eating mulberry leaves, ant silkworms become bigger and longer, shed their black color, and gradually turn white. After the first molt, they become second-instar silkworms. After that, they continue to grow. Well-developed silkworms can grow to 6-7 cm after the fourth molt and can eat some older leaves. Each time silkworms molt, they exhibit a “sleeping” phenomenon, staying without food or water for a day. At this time, do not think they are sick and disturb them. The dorsal ridges of fifth-instar silkworms turn yellow and transparent, and they do not eat much mulberry leaf, which indicates that they are about to start spinning silk and cocooning.

3. Handling of Silkworm Eggs

After male and female silkworm moths mate, they die one after another. We can freeze the silkworm eggs they leave behind and continue hatching young silkworms the following spring.

In fact, raising silkworms is relatively simple, and it does not require you to put in much effort. You only need to provide them with a clean, spacious box and a sufficient supply of mulberry leaves.