I am raising a Thai strain of silkworms. This spring, I had one good-sized group, and they all made moderately sized cocoons – except for one, which turned out tiny. The summer group, I will admit, got a little bit neglected; I moved during the middle of their cycle, and so they sometimes got not enough food, or old leaves because I couldn’t find the new ones near my new house… you get the idea. Poor little red-headed step-child worms.
So – some of them decided that life was tough, and they would cocoon early. They spun up in the fourth instar, making TINY but perfectly-shaped cocoons. My friend Eika explained that these are called trimoulters, and they are typically caused by feeding over-matured leaves.
Now – these are a naturally small strain. Chihuahua puppies are never going to grow up to be German shepherds – but the trimoulters are *freakishly* small. Here’s a comparison of normal Thai cocoons, hybrid Chinese cocoons, and the trimoulters.
and here’s a comparison of the normal (smallish) Thai pupa, and the trimoulter pupa
And, in a move that should surprise no-one, they hatch out as freakishly small moths. They’re SO CUTE. Like pinchums-widdle-cheekses cute.
Despite being tiny, they are breeding vigorously. I’m curious to see what will come of it – and whether the eggs will be visible.
I don’t comment much, but I love your dedication to your art. Thanks for sharing these photo’s. The tiny cocoon is similar to my mid season leaf, as in it has a different and unique quality in the way it dries to mature leaves.
Do the tiny trimoulters produce a different kind or quality thread / silk?
Wow, maybe you’ve just come up with a new strain of moths for apartment-dwellers! 😀 😉
I honestly don’t know about the quality of the silk – it seems natural that it would be significantly finer, but I haven’t had enough of them to experiment with yet. Maybe if I get a bunch with the next batch I’ll give it a try. So many of the techniques rely on specific characteristics of the cocoons – I don’t know if these would even have enough weight to unwind properly.
Have to just repeat the sentence…..
“poor little redheaded stepchild worms.”
Yep. Made me smile that time too.
LOL the tiny creatures look vigorous enough, and just as keen on mating as any other Bombyx moths. They have very good wings!
*takes a container of her own moths and tries to compare sizes*
At least I can see that the cocoon is smaller than my smallest cocoon (one of my silkworms spun up too early into its 5th instar; I bet I’m going to get a tiny male moth.)
I’m wondering if your micro-moths are going to live shorter than the others – they have less food supply to be sure.
It seems like they would have less reserve of fat, but also like they would *need* less, with their smaller size.
My friend Michele who had some similar tiny cocoons (from the same strain) said that hers had normal-looking full-size eggs, just fewer of them.
I had a tiny male last year that lived only 3 days instead of the usual 5 to 7 for my strain. But he was very vigorous while he lived. Mated and bred all right.
Well, you’ll see the eggs pretty soon. 🙂
You said Thai and I saw the small cocoon. I thought it was food. All ours are ok… They eat the same mulberry?
Yup, they eat the same mulberry. In their native land, they might eat a different one – some of the southeast Asian mulberries have little leaves – but if they’re raised commercially, they probably plant some variety of M. alba.