A molecular phylogeny of the hawkmoth genus Hyles (Lepidoptera: Sphingidae, Macroglossinae).

The hawkmoth genus Hyles is one of 15 genera in the subtribe Choerocampina of the subfamily Macroglossinae. Due to a remarkable uniformity, morphological characters usually used to identify and classify Lepidoptera at the species level cannot be used in this genus. Instead, we used DNA sequences comprising about 2300 bp derived from the mitochondrial genes COX I, COX II, and tRNA-leucine to elucidate the phylogeny of Hyles. The results corroborate the monophyly of Hyles but conflict with previous internal classifications of the genus based on morphology. Hyles seems to have evolved in the Neotropics during the Oligocene/Eocene epochs and the molecular data (which evolved clock-like) confirm the hypothesis that it is a very young genus that radiated on a global scale rather quickly. We hypothesize its sister group to be one of the genera Deilephila, Theretra or Xylophanes. The Nearctic may have been colonized rapidly by Hyles once the land bridge formed during the Pliocene, since within this same Epoch, the invasion of the Palaearctic appears to have proceeded from the East, via the Bering route. The colonization of Australia appears to have occurred rather early in Hyles radiation, although the route is not clear. We propose that the radiation of the Hyles euphorbiae-complex s. str. (HEC) occurred as recently as the Pliocene/Pleistocene boundary and that its roots can still be reconstructed in Asia. Hyles dahlii is closely related to the HEC, but a sister group relationship to the HEC s. str. cannot be corroborated unequivocally. HEC population ranges appear to have tracked climate oscillations during the Pleistocene Ice Ages, resulting in hybridization around the Mediterranean Sea as they repeatedly intermingled. Comparison of the phylogeny with food plant affiliations leads us to hypothesize that Euphorbia monophagy evolved at least two times independently within Hyles.