The Spanish moon moth (Graellsia isabellae) is a moth of the silkmoth family Saturniidae. The moth is native to Spain and France. At the end of April and beginning of May the moth begins to hatch after overwintering in the cocoon. Normally moths from the same parental line won't copulate, so it is necessary to take account of this when the moth is bred in captivity. After copulation the female lays about 100 to 150 eggs on the favoured foodplant, pines. The larva hatch after 1 to 1.5 weeks and begin to eat the very hard pine needles. It takes about one and a half months for the caterpillars to reach the last instar. In the last instar the caterpillars go down from the tree to pupate under leaves on the ground. In this stage the pupae in the cocoon overwinter until the next spring.