Serving the Tiny Masters


This is totally unrelated to my dream journal. This is a draft of an article I’m writing about one of my odd hobbies…

Serving the Tiny Masters:
– adventures in home sericulture –

I open the door, and I can hear them. The sound is only a soft, quiet pattering, like rain on the roof … but I know what they’re thinking. “Feed us. You must feed us. Bring the food here to us, now.” They wave back and forth hypnotically, like tiny cobras – I have to obey.

One month each spring for three years now, the Tiny Masters have ruled my life. I wake early and stumble bleary-eyed out into the yard to fetch their food. I change their trays every other day, adjust the temperature and humidity in their room so that they will be content, fuss over them and attend to their needs. The main need is food. Every day, three times a day. For the fourth and final week, four times a day. They are always hungry, the Tiny Masters.

I got started raising silkworms in 2001. A friend of mine said that she had raised them in school as a child, and they were an easy and fun project. I have been weaving for over a decade now, as well as using silk in my soap, and the vision of home-made silk for special projects was very seductive. I started looking into the requirements, and found them to be very simple, although quite firm – a clean, toxin-free environment, a ready supply of fresh mulberry leaves, warm room temperature (78′ to 88’F for fastest growth) and time. A lot of time.

Silkworms are actually caterpillars. They are the larval stage of the white silkmoth, Bombyx mori. They are the world’s only truly domesticated insect. They have been bred and selected for thousands of years, mainly for quality of silk (color, strength, volume) but also for ease of rearing. The end product is a very efficient leaves-into-silk machine; after four weeks of voracious eating, each worm will spin a cocoon that looks like a Styrofoam “peanut” composed of up to a mile of unbroken silk fiber. The worms in their current state could never survive in the wild, since they have no chemical or physical defenses to protect them from predators. The larvae (the worms) are white and soft-bodied (no camouflage or spines) and the imagos (adults) are fat-bodied and totally flightless. There is another semi-domesticated type of silkworm that produces “Tussah” silk; these feed on oak leaves, and have a very different lifestyle than the classic bombyx silkworm. They’re not receptive to hand-rearing at home. They are prickly. Sometimes it is easier or cheaper to find Tussah silk fibers for soapmaking; they are coarser and look like doll’s hair instead of the micro-fine wisps of bombyx silk.

I order silkworm eggs in the spring. I get mine from Mulberry Farms mainly because they’re less expensive. I used Sericulum the first time, but their eggs are much more expensive if you’re wanting a bunch of them. Sericulum has a lower minimum order if you’re wanting just a few. I have tried to over-winter the eggs in cold storage, but have not yet hit upon the correct balance of temperature, humidity, and timing. The eggs are the size of a ball-point ball, and come attached to the bottom of a petrii dish or a piece of paper. Sericulum’s eggs arrive in the pattern the moth used to lay them; Mulberry Farms pastes theirs down in a patch using a special glue.

The eggs hatch usually within a week of arrival. They need about two weeks from the time they’re removed from cold storage, to the time they hatch, but most of the mail order houses send them about halfway through that time. Upon hatching, the larva are tiny – about the size of a typewriter dash. They are called “kego” by the Japanese, which means “hairy baby”. The Indians call them “chawki” silkworms. They are also called “Ant Silkworms,” because they really do look like small brown ants. They typically all hatch on the same day, and usually at dawn, even if they don’t see the sun. Don’t ask me how they know, but they seem to. There are always a few early risers the day before, and a few per day for a couple of days after.

The tiny kegos have to eat within four hours of hatching, or they die of dehydration. For the first couple of days, they require only the tenderest tip leaves of the branch. Some folks say that you need to chop the leaves up; I find that tearing them in half is sufficient, because they seem to just start chewing wherever they feel like. These leaves need replacing about three times a day, mainly because they are tender and dry out easily. The worms receive all their fluids from the leaves they eat. The leaves must be fresh and clean and unwilted, but not damp. If the leaves are wet, the worms drown. I usually keep the worms in a tray with a lid to slow the drying of the leaves, but if you take this route, be vigilant about mold. If the leaves mold, and the worms eat the mold, they die. The worms expect to be fed; that’s why I call them the Tiny Masters. When you open the lid of their container, they wave their heads around, reaching for the leaves they know will be immediately forthcoming. The leaves have to be placed right on top of the worms; if you place a worm six inches from a juicy leaf, it will die. They won’t let go of a leaf except to crawl to another leaf, which is a great advantage in hand-rearing – they don’t crawl out of a tray or dish.

Silkworms grow very fast. They will increase their body size by 10,000 times within a month. Within four days, they will shed their skins, and graduate to the second instar. Instars are the stages of larval development; there are 5 of them between hatch and cocoon, each one accompanied by a new skin and a growth spurt. The second instar larvae are gray and smooth, where the first instar was dark brown and hairy. Later stages are closer and closer to pure white. After the first two instars, which each last for four to five days, each successive instar lasts about a week. Each time the larvae are getting ready to shed their skins, they will spend several hours not eating, sitting immobile with their heads upward. Afterwards, you find the shrugged-off skins on the bottom of the tray or attached to a leaf, looking like where a lazy husband stepped out of his pants.

The bigger they get, the more they eat. In the fifth instar, the larvae will begin to change their metabolism; they go from primarily increasing their own body mass, to primarily forming silk proteins. Their thorax area gets larger and larger, and they eat nonstop, night and day. After this week of gorging themselves, the worms will begin to wave their heads about as if praying ecstatically. This means that they are feeling the need to cocoon. They start to sketch silk onto anything around them, and climb upward. It is the only time in their life cycle that the worms will crawl out of their tray if allowed.

The best cocooning arrangements allow the worms to have individual compartments. This maximizes silk output by allowing each worm to make a perfect cocoon. Egg cartons work, as do small sections of paper towel tubing. I have also, when faced with the sudden cocooning of about a thousand worms at once, made little artificial bushes using wire and the branches from the mulberry tree. They climb up it, find a likely spot, and start making little silk hammocks. This silk is called “flossing.” It is tough and not always one continuous strand. After they have their hammocks well built, the worms begin the serious cocooning. The perfect cocoon is a long oval with a “waist” in the middle, and has a wrinkled surface. Some strains of silkworm will spin pure white, others spin a golden yellow. There are some rare strains that spin cocoons of other shades, but these are not readily available. The silk fiber is actually made of two smaller strands called “baves.” Silk consists of two proteins – fibroin and sericin. The fibroin makes the long strand of the silk, and the seric
in binds the strands together in the cocoon. Cocoons which have been “degummed” have been boiled or chemically processed to remove the sericin. Most silk is processed with the gum on it, since it protects the delicate fiber, and then the sericin is removed after spinning or weaving. Silk used for soapmaking is typically already degummed.

In commercial silk production, most cocoons are stifled. This means that they are treated with heat or steam to kill the pupa inside. If the moth hatches out, then the cocoon cannot be reeled off; reeling produces the finest silk. Cocoons which have hatched out (ecloded) are still useful for spinning silk, and can be made into hankies or caps. These are ways of stretching out the fibers to make spinning from them easier. If the cocoon is not stifled, then in about two weeks the moth will secrete a brown goo, which softens the sericin gum, and push its way out of the cocoon. The adults, also called imagos, are squat-bodied, covered in soft fuzz, and totally unable to fly. The males can detect the scent of the females from hundreds of feet away, using special receptors in their comb-like antennae. They mate for a few hours, and then the female will lay between 200 and 500 tiny eggs. The adults are not equipped with working mouth parts, and since they cannot eat, they die soon after mating. Their entire life cycle, from eggs to eggs, takes about six to eight weeks.

some silkworm resources:
http://www.mulberryfarms.com
http://www.sericulum.com
http://www.amazon.com/exec/obidos/ASIN/1575025426/103-1197021-2407842
http://www.geckolizards.com/photos/silkworms/
http://insected.arizona.edu/silkinfo.htm
http://www.pclaunch.com/~kayton/Silkworms/pictures.htm
http://thaisilkvillage.com/products/silk-production.html
http://member.nifty.ne.jp/kinoko-no-mori/SILKWORM/swn_e.html

9 replies
  1. sunwoman
    sunwoman says:

    The sound is only a soft, quiet pattering, like rain on the roof

    You just brought back a nice memory. My youngest was raising silkworms in his first grade classroom a couple of years ago and the teacher asked me if I wanted to hear them. They do indeed sound like soft rain and I was amazed. She looked at me oddly when I mentioned the similarity. ::laugh:: I guess not everyone makes such correlations.

  2. rjwolfx
    rjwolfx says:

    Silkworms

    You know, this is one of the most wonderful things about Live Journal. I have to say that walking down the street, you just never know what people’s hobbies are… or get to hear why they’re so interesting.

    On that note, I think you made raising silkworms sounds like a very cool thing and the article was fascinating. I found myself reading the entire thing with my head cocked and a slight smile on my face… probably not all that different from the feeling of one of your tiny masters chewin’ on a mulberry leaf.

    Thank you so much for sharing!

  3. perspicuity
    perspicuity says:

    the fresh mulberry leaves are the trick…

    the only place i’ve seen mulberry growing in quantity is in NY state, around the catskill region, and various portions of VT. they’re somewhat rarer in NH (at least “wild”), i’m sure some old farm property has some around…

    the aforementioned catskill area is rife with luna, poly-phemous and cecropia (i’m sure i’ve mangled the spellings), which apparently love mulberry – silk related?

    of course, the mulberries themselves are tasty too.

  4. admin
    admin says:

    I’m going to try rearing giant silk moths this year. Excited!! I’ve ordered pupae for Samia cynthia and Anthereae polyphemus. Hopefully I’ll be able to get them to breed, lay eggs, make babies, and give up silk.

    Can you just imagine how magical something made out of luna moth silk would be? Maybe I’ll try for that one next, if the others do OK. They’re a lot trickier than the Bombyx mori ones, which are like the disposable hamsters of the insect world.

    My grandparents’ country property in Kansas had a HUGE mulberry – we used to go up in the limbs and jump up and down on them, while Grandmother spread a bedsheet out below. Yum. They’re wild all over down here, as well as a cultivated fruitless variety that’s used as an ornamental a LOT – that’s what I’ve got growing in my front yard, plus a couple of tiny “weed trees” in the back. The fruitless seems to work just fine for worm food.

  5. chromatic_dawn
    chromatic_dawn says:

    Re: luna moths

    It was a rare sight but I occasionally saw luna moths while growing up in Tennessee. It was always a magical sight since they were so rare and only showed up in the Fall. Sometimes they were fat babies, barely able to fly, but once we were visited by the grandfather of all luna moths. This one had to of had a wingspan of close to 7 inches! All it did was sit perched on the side of our house as if, knowing how regal it was, it were merely waiting for the tribute it so readily deserved.

  6. admin
    admin says:

    Re: luna moths

    We used to see them from time to time where I grew up near Houston. They’re such magical things… the combination of the surprising shape and color, I think.

  7. grrlanimal
    grrlanimal says:

    I love silk, and I’m fascinated by the process. I do have to admit there’s a big “ew” factor for me with the worms. I used to live in Korea, where they produced a lot of silk. Being a culture where *nothing* is wasted, they cooked up the worms and they were a popular street food. Imagine HUGE woks full of these things, all piled up and reeking.

    They also sold small snails as street food – you’d buy a newspaper twist of them, suck out the meat – the floors of the busses were crunchy with the shells. This never bothered me like the silk worms did.

  8. admin
    admin says:

    Cool! Do you know if the cocoons they use were dried previously? It seems like they’d be better fresh; the ones I have that are dried have a strong smell and are all wrinkled up.

    I’ve tasted one, just to see, and wasn’t impressed. Tasted like bug. I had a fresh one, though, not one from the old dried pile.

    Recently, my big adventure has been reeling and throwing organzine – hopefully I’ll have more photos up soon!

  9. grrlanimal
    grrlanimal says:

    They DID have a strong smell and they were all wrinkled up. They were disgusting. I’m not sure how they were prepared – sauteed, I guess. I’m a very adventurous and non-judgemental traveler, generally, but EW!!!

    Your photos are great – they’re interesting AND clear – looking forward to new ones. And, if you’ll please excuse me, now I have to go find needles to make a little square bottomed bag.

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