On the left: a hybrid white Chinese strain. On the right: the Cambodian land race cocoon.
I’ve been raising some silkworms from Cambodia. They’re Bombyx mori, same as all the other domesticated silkworms – but they’ve been bred for centuries to withstand the particular stresses and hardships of Cambodia’s hot, humid climate. They are MUCH smaller than most of the regular strains, and they make a brilliant yellow cocoon.
You can see the yellow in the body. I was SURE that these had at least one more week – they look like fourth instar caterpillars, compared to any of the strains I’ve raised before. My friend who brought me the eggs, said that they were fast, and that they might be ready to spin – he was sure right.
Here, it’s a little bit back-lit, so you can see the color better. They have a deep orange part in the middle, where the majority of the sericin is produced – this makes sense, with their yellow cocoon. The yellow is in the sericin, the gum on the outside of the silk – so the reeled filament will be yellow, but if it is degummed it turns a “natural” off-white. I want to do some work using the filament raw, to keep the color.
As I said – teeny!
And here, with a not-all-that-big Zebra silkworm, for comparison. This Zebra is a straggler from a recent batch, and has hung on nearly a week after most have spun, so she’s not a great representative of the type – but you can see that the Cambodian is about 1/3 her size.