Abstract: The ultrastructures of male external genitalias of Luehdorfia species were observed with scanning electron microscope. For these four Luehdorfia species, i.e. L. chinensis Leech, L. longicaudata Lee, L. puziloi Erschoff and L. japonica Leech, the appearances of whole male external genitalias are similar, and their ultrastructures of harpago, uncus, aedeagus and juxta are markedly different. These ultrastructural characters could be used for identifying the species of Luehdorfia. According to the results from comparing the differences in morphological structures of male external genitalias and clustering analysis of the parameters about male external gentalias of these butterflies, the relationship among these four Luehdorfia species is discussed. It is suggested that L. chinensis with the most primitive structure of male external genitalia has a near relation with L. longicaudata and perhaps is the nearest to the ancestor of Luehdorfia. In contrast to both L. chinensis and L. longicaudata, nearer relation exists between L. puziloi and L. japonica.

Key words: Luehdorfia, male external genitalia, ultrastructure, scanning electron microscope