The Gastropacha are a genus of approximately ten somewhat larger species. They occur in Europe and Asia. Some overwinter as caterpillar and have only one annual flight while others like for example Gastropacha horishana produce multiple flights (in captivity).
The rearing can be somewhat tricky for the species that overwinter as caterpillar. The plants they prefer are usually deciduous. If you overwinter them too warm and they break dormancy, they die.