The Spanish moon moth (Graellsia isabellae) is the only member in the Graellsia genus. They are closely related to Actias species and it has even been suggested to treat isabellae as an Actias. Most recent insights keeps them in a separate genus.
The rearing is not extremely difficult, however some experience is required. This is a popular, but rare species, which often results in inbred. Try to obtain fresh stock. With each inbred generation, they not only become smaller, but also more and more difficult to rear.