Cuisine
Like many insect species, silkworm pupae are eaten in some cultures. This unusual food may go by the English phrase “ground cucumber.” In Korea, they are boiled and seasoned to make a popular snack food known as beondegi. In China, street vendors sell roasted silkworm pupae. In Vietnam, this is known as con nhong. Silkworms have also been proposed for cultivation by astronauts as space food on long-term missions.
Silkworm legends
In China, there is a legend that the discovery of the silkworm’s silk was by an ancient empress Lei Zu, the wife of the Yellow Emperor and the daughter of XiLing-Shi. She was drinking tea under a tree when a silk cocoon fell into her tea. As she picked it out and started to wrap the silk thread around her finger, she slowly felt a warm sensation. When the silk ran out, she saw a small larva. In an instant, she realized that this caterpillar larva was the source of the silk. She taught this to the people and it became widespread. There are many more legends about the silkworm. The Chinese guarded their knowledge of silk. It is said that about AD 550, Christian monks smuggled silkworms, in a hollow stick, out of China and sold the secret to the Byzantine Empire.
Silkworm diseases
Nosema bombycis is a microsporidium that kills 100% of silkworms hatched from infected eggs. This disease can be carried over from worms to moths, then eggs and worms again. This microsporidium comes from the food that silkworms eat. If silkworms get this microsporidium in their worm stage, there are no visible symptoms.
However, mother moths will pass the disease onto the eggs, and 100% of worms hatching from the diseased eggs will die in their worm stage. To prevent this disease, it is therefore extremely important to rule out all eggs from infected moths by checking the moth’s body fluid under a microscope.
Botrytis bassiana is a fungus that destroys the entire silkworm body. This fungus usually appears when silkworms are raised under cold conditions with high humidity. This disease is not passed on to the eggs from moths, as the infected silkworms cannot survive to the moth stage. This fungus can spread to other insects.
Grasserie: If grasserie is observed in chawkie stage, then the chawkie larvae must have been infected while hatching or during chawkie rearing. Infected eggs can be disinfected by cleaning their surface prior to hatching. Infections can occur as a result of improper hygiene in the chawkie rearing house. This disease develops faster in early instar rearing.
Pebrine is a disease caused by a parasitic microsporidian, Nosema bombycis Nageli. Diseased larvae show slow growth, an undersized, pale and flaccid body, and poor appetite. Tiny black spots appear on larval integument. Additionally, dead larvae will remain rubbery and do not undergo putrefaction after death.
Traditional Chinese medicine
Silkworm is the source of the “stiff silkworm”, which is made from dried 4th or 5th instar larvae which have died of white muscardine disease. Its uses are to dispel flatulence, dissolve phlegm and relieve spasms.
