Tips N' Tricks #3

Marion's Wonderful World of Silkworms

Silkworm Pictures Here

When the first sign of spring arrives, I find myself thinking it is time to hatch out some silkworm eggs. But, first I have to visit the Mulberry tree to see if the buds have started to form on the branches. It is best to wait until the leaves have begun to fill the branches before starting the hatching process.

The eggs have been stored in the refrigerator all winter long keeping them dormant. After removing them from the refrigerator I place them in a paper lined shoe box. Marking the date, I count the days until the hatching begins. It takes about 15 to 20 days before the tiny worms appear. They are black and resemble an ant.

The first feeding is by cutting the leaves into small pieces so the little worms can begin eating. After about 3 days you don't have to cut up the leaves because they have already grown large enough to climb on the larger leaves. The leaves must be dry because wet leaves will make them sick and most worms won't eat a wet leaf. Every day you must remove the old leaves. The eaten leaves will have little holes chewed throughout. About the 4th day you clean the whole box. Keeping the boxes clean is very important because you want healthy worms, not sick ones. They have to be kept in an even temperature and kept out of drafts. They will not survive in the sunshine.

A domestic silkworm is completely dependent on humans for survival. They will not travel more than 12" in their life span. They do not see very well. They will never leave the box and go wandering.

The growing periods between the molting are called "Instar" periods. They go through four molts. Just before molting, which means shedding their outer skin, the silkworm will be perfectly still for about a day and will not eat. They hold their heads up in the air. This is called "sleeping". Once the molting takes place they begin to eat ferociously. When they are in the fifth instar they will eat more than ever before. You almost have to feed every two hours to keep up with them.

Now is the time to begin building the "Condos". I have found that building condos is better than using egg cartons or paper tubes. When the silkworm is ready to spin the cocoon they will actually shop for a place to settle in.

First thing they do is spin a hammock stretching from side to side of the condo. When they are secure they begin spinning the cocoon, covering their entire body with spun silk. They make their heads go in a figure eight pattern and use the small hook on their tail to anchor the threads. The spinning process takes about three days. When they are finished spinning, the cocoon will be quiet for about 15 to 18 days. Finally the feeding period is over.

In the silk industry they do not let the moth emerge from the cocoon because they want the silk thread to be one long consistent thread. They reel the silk directly from the cocoon. But as a small silkworm grower I'm not concerned about reeling. I let the moths emerge from the cocoon. Emerging from the cocoon will always take place between 7:00AM and 8:00AM so one should be on hand to gather the moths at that time of day. The moth will make a hole in one end of the cocoon and begin to crawl out. You must not try to help them because it will disturb the process. As soon as the worm is out it will hang on the hammock for a short time until it's wings unfold. As soon as they start to move about it is time to place them in the mating box. The female has a larger body than the male and as soon as she is in the box she excretes an odor to attract the male. The males will begin to flutter and fight for the females attention. As soon as the mating takes place the female will break away and find a spot to lay her eggs. A female may lay as many as 300 eggs but they may not all be fertile. The moth does not have a mouth or a stomach so they will not eat your clothes. Also the silkworm is unable to fly because their wings are not strong enough to lift their heavy bodies. But they do propel themselves by fluttering their little wings and can travel about the mating box. Sometimes they can get enough momentum to get over the side of the box but they will not go far.

The mating period is about 5 days. The moths actually starve to death. Their wings will be all tattered and worn.

The eggs are yellow when they are first laid and then turn a dark grey color. The ones that stay yellow are not fertile. I put a sheet of wax paper (the kind that comes in a box like Kleenex) in the box for the eggs to be laid on and then I can save them by rolling up and placing in cardboard tubes (like paper towel tubes). This is an easy way to store them in the refrigerator. You must not store the eggs in plastic bags because they have to have air circulation for the eggs to survive.

The most important thing about silkworm raising is that you have a couple of Mulberry trees available and also the time to spend in caring for them.

The process for degumming the cocoons is time consuming too. I have found through different procedures that taking each cocoon and opening with scissors to remove the pupal shell which the moth has left behind is best. I usually process about 50 cocoons at a time. I place them in a large pot and cover with water. I use 1/4 cup of Ivory dish detergent and 1/4 cup of washing soda for the solution. Bring the pot to a boil but don't let it boil, just simmer for about 1/2 hour. Turn off heat and let the pot cool down so you can easily handle the cocoons. Under running water rinse the silk and spread it out into a square. Spread the silk over an upturned square plastic container. Layer the squares until you have about 10 or 12 thick. This is called making small Mawattas. You can either dry them or put them in the dyepot right away.