Silkworms at 48.9N 8.2E

Wednesday

April 20 2005

10-20C 50-80% rh

They finally arrived today!

I had found the address on Google and here are

eggs of Bombyx mori

Apparently two different types.

I guess one has to be into it to find them pretty. Fascinating anyway. Unbelievable some of these will develop into 6 cm long worms in few weeks and then produce a 2000 m silk thread.

Lets get going! First thing I have to set the environment right. 23-25C, high humidity. Just around midnight I get there with my little plastic box incubator.

It is not too early: The mulberry trees (morus alba) just show the first leaves.

Thursday

April 21 2005

24-25C 70-80% rh

day -(x-1)

yyy worms

No new developments, temperature stable, blog format established.

Friday

April 22 2005

20-27C 60-80% rh

day -(x-2)

yyy worms

I have played a bit around with my temperature setting, trying to lower the average a bit after looking at the korean website on how to raise silkworms. They have the temperature lower for the eggs and don't talk about humidity so I tried to take both down. Question:

When will the first worms hatch? The mail in which they came is stamped April 18. Assuming they took the eggs out of hibernation the day before, the antworms should hatch some time between April 26 and April 30.

Consequently:

5 < x < 11

Saturday

April 23 2005

24C 80% rh

day -(x-3)

yyy eggs 0 worms

No activity today. Temperature stable.

One might wonder how in the world someone gets the idea of raising silkworms! Well, for me it's a story that goes back 40 years or so, but it begins in the late 90's with the most inspiring person. Renate. If she had a website I'd link to it. She raises silkworms, and takes them into school in the DC area. She feeds them with the leaves of the mulberry trees that grow as weeds there. Once she has put you in charge of taking care of her worms you learn to recongize a mulberry tree out of the corner of your eye.

Of course this whole life cyle and metamorphosis thing is realy cool. But for me there is an extra buzz in it. I'll write some other day about that.

Sunday

April 24 2005

24C 80% rh

day -(x-4)

yyy eggs 0 worms

This entry only serves to demonstrate to my son how to edit the html file.

That should do. I took an old pair of binoculars apart to get two more lenses. With these it should be possible to image the antworms.

Monday
April 25 2005

day -(x-5)

23C 80% rh

1100+ eggs
0 worms

Tuesday
April 26 2005

day -(x-6)

23C 80% rh

1100+ eggs
0 worms

Wednesday
April 27 2005

day -(x-7)

23C 75% rh

1100+ eggs
0 worms

Thursday
April 28 2005

day -1

23C 70% rh

1100+ eggs
3 worms

Finally the frist worms have hatched. Watch number three by clicking on the image to the left.
Lucky I caught this one in time. It took it a few minutes to get out while I kept taking pictures. Assembling some of them into an animation was another thing, as I had taken the pictures freehand

I found the first two this morning. went into the garden to pick the first mulberry leave and moved them over with the corner of a piece of paper. And they went right at it: eating.

Friday

April 29 2005

day 0
23C 70% rh

<1000 eggs
>100 worms

Now they are hatching! This morning I found quite a few of them sitting on top of the eggs waiting to be moved. I took a feather that our guest parakeet had lost to "feather" them over to the mulberry leaves. On can tell right away that they do not wait with spinning until they are grown. As soon as they are moved they stick to the place and eventually hang on a fine thread. You can see in the picture below several of them hanging on their threads. As soon as they are on the mulberry leaves they start eating, after a few minutes there are already holes in the leaves.

By clicking on the images below you can get large versions in an extra window. The same is true for some of the images above. Usually those with a link have frames around.

Saturday
April 30 2005

day 1
26C 80% rh

<500 eggs
> 500 worms

Sunday
May 1 2005

day 2
26C 80% rh

<100 eggs
> 900 worms

Monday
May 2 2005

day 3
26C 80% rh

<10 eggs
> 900 worms

Tuesday
May 3 2005

day 4
26C 80% rh

<10 eggs
> 900 worms

Worms kept hatching on Saturday and early Sunday with a few latecomers on Sunday evening,one Monday. They grow like crazy. The first worms start to do the first molt. Actually I do not know if it is really the first one, I cannot imagine they grew as big as they are without, but I did not see any signs for it so far.

With the mulberry trees I had more luck than brains. When I asked for the eggs we had the first greens on the trees. But when the eggs came the green did not really continue to grow as the temperatures went down. When I picked the first leave I found some brown spots, which I take for frost defects.So I am lucky we did not have more late frost than the one in mid April. When I checked for some of my "external resources" I found those trees even further back than the ones in my backyard. Some of them do not have leaves at all yet, but only flowers. (As it seems male and female flowers are seperate on the same trees.) Luckily the weekend was very warm, so that they all grew a lot. Now I hope the icemen will pass without another frost. Rule for the future: Wait past the icemen before starting to grow silkworms north of the alps.

Now we have different sizes of worms: about a third has finished (first?) molting, half is still in the process and the rest is following up. The image above shows the whole variety: a few hours, one day, two days (in molting) and three days old. The three day guy weighs 10 mg, about 200 times as much as the egg.

See the crosses in the back? They are 1 mm (40 mils) appart.

Wednesday
May 4 2005

day 5
25C 80% rh

no more eggs
> 900 worms

This morning, after driving my son to school, I picked some more leaves and had a closer look at the different trees. Now the trees that had leaves first also have flowers. But they look different. So these must be the female flowers. Then I was wrong. Mulberries are dioecious, male and female flowers on seperate trees! Checking the web gives numerous references. What I had taken as female flowers at first glance where the closed male flowers. Makes perfect sense. In the park there are two males and two females in symmetric arrangement!

Thursday
May 5 2005

day 6
21-26C
50% - 80% rh

no more eggs
> 900 worms

Friday
May 6 2005

day 7
24-25C
50% - 80% rh

no more eggs
> 900 worms

Wednesday night food ran low, so I decided to lower the temperature in my incubator to reduce the worms metabolism until Thursday morning. That seemed to work fine.

Meanwhile most worms went through the second molt, which I found much less spectacular than the frist.

BTW: Female (left) and male (right) mulberry flower.

Saturday
May 7 2005

day 8
(20) 22-24C
(50%) 80% rh

no more eggs
> 900 worms

It is cold outside, only 15C or so. Inside we have it cooler as well, consequently the worms cool down fast once I open their box.

This morning I fetched another batch of leaves. It takes quite a few now. I have started to write down how much I need. Todays plastic bag contained 250g, about as much as I had so far all together. Will see how long it lasts. More accidently I glanced at the old egg papers and found a latecomer. You can see it at the picture on the left. Click it to see how it compares in size with the older ones!

Sunday to
Wednesday
May 8-11 2005

day 9-12
22-23C
70%-80% rh

no more eggs
1050 worms

male left male right female left female right

Thursday
May 12 2005

day 13
24C
80% rh

no more eggs
1050 worms

Can you find the mulberry trees on the image above? Move the cursor over the image to find them! This is the one of my mulberry leave sources that I had written about earlier. As temperatures are low outside they are still pretty far back. I might run into trouble trying to provide enough food as most of the other trees are also slow in growing leaves.

Most of the worms have meanwhile finished what I think was third molt. Two days ago I weighed them and found most of them with a weight in the narrow range of 190 to 220 mg. Only those hatched on the third day where at 150mg. And there was one with 500mg, which I take as a hint that they will soon all start eating a lot. I had sorted the worms into different trays after they had hatched and I determine the weight by weighing 10 from each box and deviding the results by 10.

It is fun now to watch them eat. to take out a bite like in the image series here takes a minute or so.

Friday to
Sunday
May 13-15 2005

day 14-16
20-23C
60%-80% rh

no more eggs
1050 worms

For the next part click here!

Questions, suggestions? Just E-mail!