Androconial hairbrushes of the Syntomis (Amata) phegea (L.) group (Lepidoptera, Ctenuchinae): A synapomorphic character supported by sequence data ofthe mitochondrial 16S rRNA gene

Males of several palaearctic Syntomis/Amata species (Lepidoptera: Arctiidae ) possess androconial hairbrushes in connection with the foreleg core. The cuticular structure of these potentially behaviour-related and pheromone di ssipating brushes is described. Such male-specific organs and signals play a crucial role in the female choice procedure. The presence of hairbrushes was found in 17 out of 28 inspected species df the tribe;Syntomini. All mem bers of the Syntomis phegea group (Europe to Central Asia, as well as Caspi an, Caucasian and near-middle East species) have these structures, and only three oriental and south Asian, but none of three African species, carry t his trait. The common genetic base of this morpho: logical character is sup ported by an analysis of mitochondrial 16S rRNA from 19 representative taxa ; species with hairbrushes form a monophyletic clade and the brushes are a synapomorphic character. This genetic finding corroborates the ethological significance of these organs. Phylogenetic data show a substantial genetic divergence between the tribe Ctenuchini (New World species) and the Old Wor ld Syntomini. Furthermore, DNA sequence data suggest a split of the genus A mata (sensu Obraztsov, 1966) in two distinct genera, Amata (without hairbru shes) and Syntomis (with hairbrushes).