Silk worms love to eat the White Mulberry tree’s leaves and prefer them over any other type of mulberry tree leaves. They will only eat other mulberry tree leaves if there are no white mulberry tree leaves. This is a good thing for silk worm breeders because the best quality silk comes from silk worms that eat white mulberry leaves. Other types of mulberry leaves lead to a worse quality of silk and the worms don’t care for them.

From the limited searching I did - it seems like they will eat all types of mulberry tree leaves. Originally, the silkworms were fed White mulberry (native to Asia); however it seems that many people feed what ever mulberry is around. This includes the Red mulberry (native to North America). A good resource is this website:

This is a teacher who has a lot of resources on growing silkworms in the classroom. She may be able to help you answer this question.

Mulberry trees include at least ten different kinds ('species'), and are live in many places in North America, Europe, and Asia. Silk worms come from China and Korea, and they eat the kind of mulberry that lives in those countries. We have planted that tree in our country, so the silk worms can eat it here, too, but I do not think that they eat the other types of mulberry that live in other parts of the world.