Which organisms grow on the cases of caddisfly larvae?

Sponges and algae are known to grow on the protective cases constructed by caddisfly larvae.1

While these organisms inhabit the exterior of the cases, other life forms interact with the larvae themselves; for instance, protozoans and mites may grow on the bodies of certain species. Additionally, some parasitic wasps utilize the larval cases as a site for their own development, laying eggs inside the case where the parasitic larva will eventually consume the caddisfly host.1