I would also like to add that having only one silkworm is quite useless as it will not breed without a mate.
When I was a kid, I got mine from a kid who used to live near my grandma's place. I started out with only 7 silkworms. There were 2 female and 5 male out of the 7, but somehow one female and one male silkworm decided to make a single cocoon together. That extra large cocoon turned out to be too thick and they were unable to chew their way out of it alive. By the time I cut the cocoon open because it was way overdue, the two moths inside were already dead with one clearly a female. So I left with just one female and it laid hundreds of eggs.
The next spring I was able to give away most of the small second generation silkworms to many of my friends.