The sperm ultrastructure of Stictoleptura cordigera (Füssli, 1775) (Insecta, Coleoptera, Cerambycidae).

The spermatozoa of the longhorn beetles Stictoleptura cordigera were ultrastructurally described in this paper. They have an apical bilayered acrosome, an elongated nucleus, a centriole with star-shape links, two asymmetric mitochondrial derivatives partially crystallized and a 9+9+2 flagellar axoneme with accessory tubules provided with 16 protofilaments in their wall. A centriole adjunct is present and gives rise to two thick laminae as accessory bodies, also asymmetrical, to which two relatively small puff-like structures of different size are connected. These features were previously found in the sperm of the cerambycid Morimus asper. The strict similarity of the cerambycid sperm characters with those of curculionoids indicates a clear phylogenetic relationship between Chrysomeloidea and Curculionoidea.