The Collaborative International Dictionary of English v.0.48:
Silverspot \Sil"ver*spot`\, n. (Zool.) Any one of numerous species of butterflies of the genus Argynnis and allied genera, having silvery spots on the under side of the wings. See Illust. under Aphrodite. [1913 Webster]WordNet (r) 3.0 (2006):
silverspot n 1: butterfly with silver spots on the underside of the hind wings