Silkworm raising …here we go round the mulberry bush, the mulberry bush

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One of the best nature activity projects my children ever pursued was during the third grade, raising silkworms. It’s an exciting one.

You can get the eggs from the Silkworm Museum in Yokohama. They refrigerate well until whenever you wish to hatch them.It’s a great project whether for the classroom or the home-school and reallyeasy to do — except the part of feeding them. But the kids learnt tofamiliarise themselves with mulberry trees, they are the bushes that can befound everywhere in Japan on the wayside, in parks, around the jutakus. Allyou have to do is recognise the assymetrical leaves that are very prominent.

When can you raise them? As soon as the mulberry trees come into leaf inspring — until the leaves are gone in autumn or early winter. Make sure youhave enough time before they turn into silkworm moths if you are doing itlater in the year.

The larvae are small and dark and look much like any other caterpillar
larvae. They crunch up so much mulberry leaves and grow very fat and whiteas they go through their instars stages which are the five stages in betweentheir moults. They don’t move very much at all, in fact, due to centuries ofbreeding by silkworm farmers, this species has lost its ability to walk.Most of the time when they are awake, they are eating, crunch, crunch,crunch….so loud…like the sound of falling rain as the Japanesesay…literally so. And they sleep with their heads held up stiffly at aforty-five degree angle.

The kids get very busy running out to get freshleaves, as twenty-five caterpillars eat up their leaves every two-threehours. Luckily for us, a bush isn’t too far away.

And many of the silkwormsthen started making their cocoons…fascinating to see them spinning theirthreads in stages… beautiful cocoons and tough threads. Many books willtell you frames are needed, but we used toilet rolls, cut them in half, andone or two silkworms will use each one as their home.

My kids were touching them, holding them, even my husband who has caterpillar phobia(truly!) overcame his fear and grew fascinated with them. We had onecaterpillar die on us.

We watched the metamorphosis fromsilkworm to silkworm moth. The cocoons are oval, beautiful white (white acozy little home, the coziest the kids thought) and because the threads aretough, the silkworms can’t eat or bite their way out as do other species,but dissolve the cocoons with a special enzyme or something (the silkwormfarmers avoid spoiling their precious threads by cutting in half the cocoonand killing the silkworms, so very few silkworm moths actually hatch, only
for breeding purposes…my kids were devastated to find this out).

A goodbook to read is Silkworms by Sylvia A. Johnson (a Children’s Science BookAward winner) … all you need. There is the translated Japanese version called “Kaiko”.

Blow-by-blow account via photos of my kids’ project called My Silkworm Story can be viewed here.


The silk museum is worth paying a visit, though it is no close substitute for raising the silkworms yourself.

We also combined our silkworm-raising activities with readings of The Silk Route, and other books about the Marco Polo era.

SILK CENTER AND SILK MUSEUM (SILK HAKUBUTSUKAN) On the first floor of the Silk Center is the Tourist information Center. There is an undergroundshopping arcade and the 2nd and 3rd floor make up the Silk Museum. Exhibitsshow the silk manufacturing process, and scarves, silkworm cocoon-dolls, andother silk products are sold here. 15 min. walk. Open 9:00 a.m.~4:30 p.m.Closed:Mondays and around New Year Admission: College/High school students ¥200 Junior high/Elementary students ¥100

Silk Museum: The museum is one of the Silk Center building’s important activities.Its principal objectives are : to disseminate an understanding of thescience and technology of silk production, display beautiful costumes forpeople to admire and promote the demand for silk. Silk Center Kokusai Boeki Kanko Kaikan
No.1 Yamashita-cho, Naka-ku, Yokohama, Japan See access map here. More info availabe at this Wikipedia page.
Website URL:

TEL :  045-641-0841
FAX : 045-671-0727

We got the eggs throughour son’s elementary school teacher who got them from the Silk Center’s Silk Hakubutsukan, so you must be able to get them from the Silk Museum, though you might want to call ahead of time since there might be a seasonal limitation period or date in which they deal out the eggs.

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