Experiments with Silkworms
A batch of 250 normal Bombyx mori silkworms began hatching 11/27/19. As of 12/28/19, I had run out of their mulberry chow food supply. By this point, there were roughly 110 silkworms left to feed. I was under the impression that they would be cocooning, given they were between 30-40 days old and that’s what all my sources had said regarding when they cocoon. Once they start cocooning, they no longer need food.
"18 died in one day..."
The death rate slowed to about 1-2 per day. On 01/02/20, I bought dandelion leaves because I had been told by another person who raises silkworms that dandelion leaves are better than romaine lettuce (and I now had access to a large Asian market which offered fresh dandelion leaves). However, the silkworms still preferred both the celery and the carrots over the leaves.
In fact, they preferred months old prunes, grapes, and sliced apple to the dandelion leaves, which says something of their disdain for the romaine lettuce.
Feeling experimental, I offered them the salted seaweed salad that I had prepared for myself. It comes packed in salt, but I soaked it for an hour and rinsed it. They were roughly as enthusiastic about that as they were about the carrots. I gave them access to the dandelion, carrots, celery, seaweed, and apple while I prepared the mulberry chow that finally arrived.
On 01/03/20, the mulberry chow was ready. I was worried that the silkworms that were eating seaweed would die because it was salty, and salt can kill snails, so maybe it would kill them. So I separated the silkworms that were eating seaweed into a different container to keep an eye on them, then fed them all mulberry chow.
On 01/04/20, the group that had been eating seaweed was not only still alive, but thriving. The other group had a higher death rate and smaller silkworms. So I gave the seaweed group more seaweed and continuted to give the other group carrots. By 01/06/20, I decided to start measuring them. The carrot group originally had about 10-20 more silkworms than the seaweed group, but now it only had 1 more silkworm. 24 in the seaweed group, 25 in the carrot group. Both groups were/are consistently given plenty of mulberry chow after 1/3/20.
four Hypotheses:
Hypothesis 1:
Adding seaweed to the silkworm diet is healthy. The seaweed has nutrients that aren’t provided in the mulberry chow which allows the silkworms to grow bigger, or grow faster.
Hypothesis 2:
Hypothesis 3:
Larger silkworms are more likely to survive and will produce larger cocoons with more silk.
Hypothesis 4:
Adding carrot to the container alters the humidity in a way that is negatively affecting the silkworms and/or adding seaweed to the container alters the humidity in a positive way. As of 1/8/20 I feel the need to mention that the carrot group is in a bigger container, and it is quite possible the humidity is substantially different, given the wetness of the seaweed and the smaller size of the container they are in. As of 1/8/20, their containers are switched.
Hypothesis 5:
Just adding salt to their mulberry chow diet will not have the same beneficial results as adding seaweed.
Research Methods
I will be testing hypotheses 1, 2, and 3. I do not have a way to measure humidity, and I don’t have enough silkworms to risk a salty diet that may harm them.
Starting with one group – which is housed in a plastic container with an unsealed lid – I wash my hands with soap and water, then pick up one silkworm and place it on my left palm. With my right hand, I use a sewing gauge with the pointed end at the head of the silkworm and use my thumb to adjust the slide to the end of the anal claspers of the silkworm. I write down the centimeters, then move the pointed end of the gauge to the side of the silkworm’s neck, just under the bulge of the thorax, and slide the slider again to gently bump against the other side of the body to measure the width. It can be a bit tricky, because they move around a lot after being placed on my palm, but I’d say it’s accurate +-1 mm.
I also learned that their length changes greatly depending if they are heading towards something, so measuring methods will likely change to account for that. For most of these measurements, they were stationary in the palm of my hand. I just had to create a barrier with my fingers to stop them from waving their heads and stay in a straight line.
Data
The grey numbers in the Jan 7th, Seaweed Group column are because I did not want to disturb the sleeping/molting silkworms and measured them by holding the gauge above them. Admittedly, I was feeling less enthusiastic by the time I got to the Carrot Group and used the excuse of not wanting to disturb them and only measured the two large ones.
At this point, it is very obvious the seaweed group is much larger than the carrot group. I find myself getting distracted by playing with the large silkworms.