Apollo butterfly. Apollo butterfly, Parnassius apollo, on a flower cluster of the yellow rattle, Rhinanthus minor. This butterfly's hindwings have eyespots with a red centre; these eyespots, resembling the eyes of a larger animal, can serve as a device to startle predators when the wings are suddenly flashed open. Parnassius apollo has a widespread distribution, occurring in northern Europe and on high ground in central- southern Europe, eastwards to central Asia. Adults appear in June to August and they feed on the nectar of flowers. Photographed in France.