Mulberry Farms is not closed. They may be out of stock from time to time that's just the nature of a business that has to get eggs with a limited usable life from China.

Mulberry Farms and Coastal Silkworms pool their orders together and import the eggs and food. There are no other suppliers that I know of that order directly. They all buy from Mulberry or Coastal and then resell.

I buy everything in bulk on their schedule so that I have a constant supply at a reasonable price. No matter how you slice it though Silkworms are not a cheap feeder.