meet the bombyx mori

bombyx-mori

Make a guess, what is this? Don’t google, just make a guess…:)

Posting your guess here is optional, but in any case, this post will be updated with a kind of mini-thesis and more photographs soon…!

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Following edited from emails to some friends…

Ah one thing was that when I visited Vijetha’s village, I some of the farmers had got into silk worm cultivation at home. There was this seperate room where there were musquitoe curtains enclosing a bed of mulberry leaves on which the worms were crawling around. The mosquitoe is to protect them from a flies a particular variety of which lays parasatic eggs inside the worm. [In one of the houses, the man’s wife didn’t seem to be very happy with the situation in general, she came out and said ‘there are some of those ugh worms crawling around on the floor’ and he patiently explained yeah yeah just go pick them up and put them back!]

I’ve had one real close encounter with a caterpillar before, in my childhood days. Maybe I was 10 years or something, a kambliula (black real hairy caterpillar) had crawled up my skin and I was absolutely terrified and disgusted at the same time, had screamed and thrown it away. I got horribly itchy red rashes where it had touched me.

Here was my next encounter with a caterpillar after all those years… and that memory came up instantly. After some hesitation I actually gingerely picked one up and allowed it to walk around on my palm. After a few moments it seemed to be quite soft and gentle, so I took it outside to have a better view in the sunlight. Much to my mom’s total disgust, Anand got me two more and placed them on my palm. My my chilled out after a while and shared my fascination, especially observing the voracious manner in which they started munching some mulberry leaves!

Soon all those worms would be in cocoons, and would be boiled to extract the silk. Hmm… way of life that we’ve made… anyway I didn’t have any non-violent alternative to offer for a better way for the farmers to earn their living.

By some strange destiny these three worms are in the palm of my hand. What if I take them home? I just enquired about the feasibility of this really really stupid idea. It turned out that they would be caterpillars only for a week, and after that they’d become cocoons. Enough mulberry leaves could be kept in the refrigerator to last them for that much time quite easily. There were several apprehensions, what if they just die because of lack of some particular special environment. Ok, after all they were just worms… and Anand assured me that it was fine so I just took them.

So that’s how I ended up with three silk worms at home – white colored and quite beautiful.

These three worms might get a chance to live their life properly and naturally, to become a moth 🙂 But I don’t know what to do after that – no idea what they eat as adults – this might be even more stupider then I’d thought. Tentative plan is to just leave them free in a park/garden…

It was a daily affair to change the leaves which kind of dried up in a day, to replace them with fresh leaves. They ate a lot and crapped a lot. Became bigger and bigger day by day.

Had some photo session and took some macro images in high resolution. Their bodies were quite fat and their skin changed from white to sort of transparent.

They were just vacuuming the leaves at a great pace. Though constantly moving around, they never left the perimeter of the leaves, never wandered beyond them.

Actually my wife was teasing me that the worms would’ve been better off in the silk farm because the leaves (which I’d preserved in the fridge) were not fresh enough for them.

Still she later reassured me they were healthy and doing fine. They had grown quite fat and could see some silk strands hanging around them. Their body seemed to have a transparent liquid, and I guess that’s the substance for the silk. Btw you might know, silkworms catepillars are blind. Still… eating eating eating…

Silk – A Hardened Glandular Fluid

Silkworms possess a pair of specially modified salivary glands called sericteries, which are used for the production of a clear, viscous, proteinaceous fluid that is forced through openings called spinnerets on the mouthpart of the larva. As the fluid comes into contact with the air it hardens. The diameter of the spinneret determines the thickness of the silk thread, which is produced as a long, continuous filament.

In a few more days, we started planning that we’d just have to get a fresh set of leaves and started enquiring around in the forestry department (18th cross Malleswaram) after our morning walk. But just that morning, when we returned home, they’d stopped eating. For the first time, they’d started wandering beyond the leaves. She said they were looking for a place for the cocoon and would eat no more. We threw away the mulberry leaves.

They constantly seemed to be groping around for something. I didn’t know what they were looking for. I “undeleted” the remaining stock of leaves against my wife’s protests, and put the twigs in the basket so that they get those corners in the bends as support for building a pupa. It seemed to help and they used it, though my wife assures me that wasn’t necessary at all, and then they wove themselves into a pupa smaller than their size. Could see them working inside it until the walls became thicker and thicker and finally no longer visible. The pupa is very pretty like a silk ball.

“Steadily over the next four days the silkworm produces a fine thread by making a figure of eight movement some 300,000 times, constructing a cocoon in which it intends to spend the chrysalis stage where it is in a state of sleep and casting off its skin.”

There’s not much action in the cocoon stage but I think next week is the time when the moths are supposed to emerge (my wife knew upto this point in the lifecycle as the silkfarming she’s witnessed they never live beyond this! Even if the silk cocoons arent thick enough (“inferior quality”) then they are just thrown away. )

The amount of useable silk from each cocoon is small. One hectare of mulberry trees yields 11.25 tonnes of leaves, producing around 200kg of cocoons, but just 40kg of raw silk. The silk yield is many times smaller than this in countries such as Thailand, where the silk is reeled by hand rather than by machine. So it takes hundreds of tiny lives to produce just one silk scarf or tie.

In the case of the cocoons at my house they’re quite thick, and I could take macro photos during the process of building. It was quite fascinating.

So what to do if they emerge? I wasn’t interested in keeping them as pets, but still thought I needed to provide some kind of food before leaving them free.

Finally did some googling for “silk worm”…

Looks like adult moths don’t – cannot – eat anything. Their mouths are just rudimentary. They cannot fly either. Needless to say they don’t live for a very short time. So that solves the question of what to do with them – nothing – just let them live in the box as long as they want to:-)

After this the pupae begin the sixteen days that would normally result in the miracle of transformation to a winged being – the moth. However, if the pupa (chrysalis) remains alive it will begin to secrete an alkali, which eats its way through the cocoon, ruining the silk threads. Therefore during the commercial production of silk, only enough adult moths are allowed to emerge to ensure continuation of the species. Most of the remainder of the silkworms are killed by heat, e.g. immersion in boiling water, steaming or drying in an oven.

Finally yesterday (23rd July) saw the most amazing thing. The moth had emerged from one end of the cocoon! As explained above, it seemed to have kind of dissolved that part of the opening. Inside the empty cocoon was a dry skin – it had moulted once in there as well.

The moth was grayish white with some patterns on the wings. Only two emerged, the other one might’ve been dead maybe. And they seemed to be content just sitting there doing nothing. Except once in a way them would be (on the vertical wall of the basket) facing downwards. I don’t know if it was a coincidence or not but they both seemed to be a kind of sychronized about turning upwards or downwards.

Today, the third one had emerged as well. All three were survivors!

They just sat there the whole time doing nothing (whenever I looked at them i.e!), exept crapping every now and then.

Finally there was a lot of flapping of wings, I wondered if they were trying to fly, but no, they were just flightless.

It turns out that that’s a way to attract each other and then they seemed to be in an urgent need to pass on their genes but I had no idea which was male or female – well they seemed to know more or less what they were doing!

Anyway that’s the story so far… hope I don’t end up with a silk worm farm or something…

(Reference for quoted text: http://www.vegansociety.com/html/animals/exploitation/silk_worm.php )