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picture of silkworms

Silkworms and what you should know

Silkworms (scientifically named Bombyx mori) are a type of lepidopteran insect native to Asia, now breeding in many regions around the world. Although it is true that there are other species, this is the most widespread and the best known.

What are silkworms?

Silkworms will go through different stages throughout their lives, consisting of moulting phases.

In these phases they will develop their organs and their size will increase. Finally, a chrysalis will be created and they will metamorphose into butterflies the moment they reach adulthood and they do this for only one purpose: to reproduce.

Throughout their lives they go through 6 stages; 4 of them will carry it out in phases of molt. In addition, inside the chrysalis they will also perform two other phases.

How to raise silkworms?

Raising silkworms is an interesting practice that will help the youngest ones to live an unprecedented biological experience, observing how the insect finally transforms into a butterfly: from a very small egg will be born a worm that will increase in size until it forms a cocoon of silk, where the transformation will be completed.

To raise silkworms we will only need the following tools:

  • Cardboard box: place where they will live. This box should have a lid to prevent them from escaping.
  • Live eggs or worms: It is much easier to find worms (near mulberry leaves or in stores) than eggs. Mostly because you won’t even see them.
  • Mulberry leaves: The food of worms.

You should know that worms will be born in spring, so if you decide to start breeding from eggs, you should catch them in autumn or winter.

The top of the shoebox must have holes in it so the worms can breathe.

First, we will begin to give them mulberry leaves that are small when they are still larvae. As the size of the leaves increases, so should the size of the leaves. Important: The only food of the silkworms is the mulberry leaves, under no circumstances should you give them lettuce or other food.

When they’re ready, the worms will form the chrysalis. As soon as this happens, we must clean the area, as it will have emitted a liquid easily recognizable by its characteristic color.

If they have emerged from the chrysalis, they can be removed. That’s when they start pairing up to lay new eggs. Keep in mind that the butterflies will die in the box, but if you let them go they won’t lay eggs.

When they lay eggs?

The truth is that silkworm egg laying will depend on the geographical location. The most normal thing is that they are born once the winter is over, rather than in spring.
When they hatch

We can tell when they will hatch by the color of the eggs. In the meantime, they should be kept in a cool, dry place (for example, in the refrigerator, on a special tray to keep them safe).

  • If the colour of the egg is still dark, this will indicate that the larva is developing and that there is still plenty of time for it to hatch.
  • If the color is rather light green, this indicates that hatching is imminent, so in a few days will be born.
  • However, if the colour of the egg is yellow, the worm has already hatched or has never been fertilised, no worm will be born.

What the silkworms eat?

As we have already mentioned, silkworms only eat mulberry and under no circumstances should they eat anything else. In some Internet sources we can find people who give you lettuce; this is not recommended under any circumstances, as it is not a food they can tolerate.

If we choose to ignore this warning and lettuce food, it is likely that they will die.

Make sure they never lack mulberry. To keep it from drying out, we can keep it in the fridge.

If you’re wondering if the butterfly, once it’s out of the chrysalis, is still eating mulberry, the answer is no. The truth is that the butterflies are not going to eat anything, they do not need to feed themselves because they will be born with all the necessary reserves to carry out their reproductive function: they will look for a mate, lay eggs and eventually die.

What do silkworms drink?

Don’t waste your time giving water to a silkworm, or any other kind of liquid, as they don’t drink. They get all the nutrients they need through mulberry leaves, both drink and food.

Care of silkworms

  • Egg care: Eggs should be stored in a cool, dry place until hatching time, usually in the spring. You have to pay close attention to the temperature. In winter it is common to turn on the heating; if the eggs are not kept properly, the larvae may hatch thinking that spring is here. The mulberry tree has not yet had time to grow, so the silkworms could starve to death.
  • Catching the worms: It is not recommended to catch the worms when they are very small (when they are less than 5cm long) as we can harm them. From these dimensions we can already dare to take them, but we must always do so with great care, as they are very delicate.
  • Mulberry tree: With the mulberry tree you also have to be very careful. The trees that give them are usually fumigated. If we pick mulberry leaves on the street, we may end up poisoning our worms. To prevent this from happening, we can always go to a specialized store and buy them there.

Why silkworms die?

There may be many reasons why silkworms can die, but these are the most common:

  • Accidents: It often happens that a worm eats very close to another worm and by accident one of them is bitten. The worm that has been bitten will run out after itself leaving a trail of blood with a characteristic yellowish color. Usually nothing happens to them and in a few minutes they will stop bleeding, drying out their wound. If this one’s too big, it won’t survive.
  • Poisoning: Death by poisoning is identified because the worm will twist into a U-shape. It may be because the mulberry leaves we gave them have been fumigated. In the event that we detect the problem in time, we can remove the leaves and get a new batch that has nothing to do with the previous one. If we’ve acted diligently, the worm will stop squirming. If we see that the dorsal artery (located near the area) does not beat, the insect will have died.
  • Pebrina: Pebrina is a type of disease that has been produced by the germs of the protozoan Nosema Bombycis. The main symptom is a characteristic delay in the development of the worm, loss of appetite and certain difficulties in making the chrysalis.
  • Flaccidity: The most dangerous disease a silkworm can face. It will usually occur after the fourth molt has occurred. The worms will apparently be healthy but will stop eating at any moment, the skin and body will become very soft. Eventually they will die, the skin will break off and a dark liquid with an unpleasant odor will escape, the larvae may create the cocoon, but it will die in the form of a chrysalis and the silk will stain. Even if the butterfly has finally fulfilled its reproductive function, the eggs will still be infected with the disease.
  • Muscardine: And finally we have this disease that has its origin in the fungus Botrytis bassiana. The worms that are attacked by this fungus die in a short time; at first they will become soft and then they will turn a characteristic pink color, becoming very hard, like petrified. In fact, they will be covered with a white mold, giving the appearance of being wrapped in plaster.

What are silkworms for?

Manufacturers use worm cocoons to extract silk. These cocoons have a thread that stretches between 1000-3000 feet (between 304-914 meters) at the time they are untangled. In order to get one pound of silk, between 2,000 – 3,000 cocoons will be required. It is estimated that 70 million pounds of silk are created each year, so we can now calculate how many cocoons it would take to achieve such a high level of production.

The manufacturer will be responsible for removing the larvae in the harvesting process, so that the silk thread is always in good condition. If the larvae come out, it will break the cocoon, so the silk will not be used to make cloth.

Silkworms are also used as research in studies related to hormones, pheromones, physiology and brain structure. Studies are currently underway to determine whether silkworms could be fed with other substances and not just mulberry leaves.

As we have already mentioned, they can also be used for learning purposes, allowing you to see how a worm emerges from a simple egg that, after multiple transformations, will end up becoming a butterfly.

Because they lift their heads and stand still?

There are many reasons that may explain this behavior, some of them not very good. The most common thing is that they are going through some phase or are preparing to make a change.

However, some symptoms of certain diseases, the vast majority of which are fatal, also portray this type of behaviour.

Many experts will recommend, if only as a precaution, that we remove this worm from the set. This way, if you have a contagious disease, we will prevent the rest from becoming infected and dying.

Where to keep the silkworms?

When eggs are not yet hatched, they should be stored in a cool place. We don’t want them to be hot before spring comes; that is, when the mulberry leaves start to grow; if this happens, they won’t have the food to survive. When they are eggs, they should be kept in the refrigerator, but always in a protected container, so that they cannot be crushed.

Once born, they should be stored in a cool, dry place. The best thing to do is to use a cardboard box, but it is absolutely essential to find the best place to place it, in order to avoid problems.

Can we eat silkworms?

In some cultures, both silkworm pupae and chrysalis are eaten. For example, Koreans make a special snack that consists of boiling chrysalis in water and then seasoning them. This dish is called beondegi.

photo of cooked silkworms

On the other hand, the Chinese use the dry bodies of worms to create a medicine that in theory should relieve symptoms such as spasms, flatulence, spasms, even to dissolve the phlegm produced by certain diseases.

Where to buy silkworms?

If we are lucky we can find them near the mulberry trees (as long as they have not been fumigated). However, if this is not the case, we can always go to a specialized store, buy them on the Internet or try to contact a private user who sells them.

The cost will depend on what each person asks for, but we guarantee you that the price is quite affordable. Here we will leave you a link where you can buy silkworms on the internet:

With this complete guide you already know what silkworms are, as well as some of their most important particularities.

Now all that remains is for you to put this article into practice if you find it interesting and discover the whole process step by step, if you do it with children, they will surely end up happy to participate.


This article has been translated with deepl.com para gusanosdeseda.info