Approximately 18 million years ago, a plant species known as mulberry emerged on Earth. Originally thriving in warm and humid regions, this perennial plant gradually transformed into a deciduous species upon reaching temperate areas.
The mulberry tree is a tall and robust plant with large, lush leaves. On Earth, numerous insects live as parasites on mulberry leaves; some feed on the plant’s roots, others on its branches, some on its buds, and others on its leaves. The silkworm is a type of insect that specifically feeds on mulberry leaves.
In addition to mulberry leaves, there are cassava leaves, fig leaves, and willow leaves…
Do silkworms eat mulberry leaves exclusively from a young age? Not necessarily. Currently, there are many known plant types that silkworms can consume. Besides mulberry leaves, they can also eat cassava leaves, fig leaves, willow leaves, dandelion leaves, lettuce leaves, onion leaves, and Brahmi leaves. However, mulberry leaves are the silkworms’ favorite food, as they primarily rely on them for sustenance during their life cycle. Through many generations feeding on mulberry leaves, silkworms have gradually developed a preference for this food, which has become a hereditary trait.
A chemist once analyzed the scent of mulberry leaves. After drying the leaves at a high temperature of 132 to 157°C, he extracted a type of oil in a test tube. This substance is volatile and emits a scent very similar to mint, detectable even from 30 cm away. Once silkworms sense this aroma, they quickly crawl towards it. This indicates that it is the most familiar scent signal for silkworms.
Silkworms rely on their olfactory senses to distinguish the smell of mulberry leaves. If their olfactory and gustatory organs are damaged, they cannot differentiate the scent of mulberry leaves. Consequently, they lose the ability to choose and may consume leaves from other plants indiscriminately.
In recent years, studies on artificial silkworm feed have revealed essential nutrients required for their development and the minimum amounts needed. Thus, as long as alternative feed containing these nutrients is found, silkworms can continue to grow and thrive as usual after consuming it.