I once raised hundreds (maybe even over a thousand) of Bombix mori, just to show my daughter the lifecycle of moths. My sister in law runs a silk farm. I asked her for “a few silk worms” and she mailed me a whole box of them, across more than 1000 km. I literally got a box of worms in mail and opened it. The upkeep until they spin cocoons was hilariously difficult when we don’t also have a mulberry plantation. We literally had to mobilize the whole family (me, my wife, my parents, and my 80+ year old grandma) to hunt for wild mulberry trees and collect enough leaves to feed those always hungry mouths. When we put a pile of mulberry leaves in the box, because there were so many worms, we could hear them chewing the leaves a meter away. And because they grow bigger, eventually we realized we had to split them into multiple boxes. And when it was time to spin cocoons, some of them decided to go rogue, escape, and spin cocoons in random places of my home. (Before they are ready to spin cocoons, they pretty much just stayed in the open boxes and ate and ate and ate.)

Anyway, I only knew that B. mandarina are wild relatives of B. mori, but photos of their cocoons found on the internet make me think they don’t spin enough silk to be worthwhile for yarn spinning. I never encountered another species that spin enough silk. So I learned something new today. Thanks again.