Morphological, molecular and phylogenetic characterization of Leptopsylla segnis and Leptopsylla taschenbergi (Siphonaptera)

The taxonomic status of Leptopsyllidae family has remained controversial over the years. Thus, some entomologists placed this group of fleas within Ceratophyllidae family, considering it at level of Leptopsyllinae subfamily or even appearing as a paraphyletic group within Siphonaptera phylogeny. This fact is emphasized by the lack of molecular and phylogenetic data of Leptopsyllidae taxa available in public databases. The aim of this study was to carry out a comparative morphological, phylogenetic and molecular study of two species of Leptopsylla genus with zoonotic relevance (Leptopsylla segnis and Leptopsylla taschenbergi) isolated from rodents collected from different geographical areas of Europe in order to molecularly characterize both taxa and to establish their taxonomic and phylogenetic status within Leptopsyllidae family. For this purpose, we have analysed and compared several morphological traits between L. segnis and L. taschenbergi and compared five different molecular markers (ITS2, EF1-alpha, cox1, cox2 and cytb) among these both species and others belonging to Leptopsyllidae family. Based on the morphological results, we found a phenotypic plasticity phenomenon in one female specimen showing morphological characters of L. segnis but molecular sequences distinctive for L. taschenbergi. Furthermore, the molecular and phylogenetic analysis could easily discriminate among both species providing, by the first time, a monophyletic origin of Leptopsyllidae family. Lastly, with this work, we demonstrate one more time, the usefulness of the combination of mitochondrial and nuclear markers to solve taxonomic and phylogenetic issues within Siphonaptera field by the use of concatenated dataset.