Host habitat and position on host affecting the evolution of chewing lice (Phthiraptera): Phylogenetic analysis of Ischnocera in Saudi Arabia

There are very few reports discussing the higher level phylogeny of the chewing lice (Phthiraptera) and their roles in the evaluation of these insects. So, the aim of this work is to study the phylogeny of genera of the suborder Ischnocera in Saudi Arabia using morphological, ecological and molecular criteria trying to answer a very important question about ecological factors that affecting their evolution. The results show high degree of similarity between phylograms produced by morphological and ecological criteria and that produced by genes sequencing data of Cytochrome Oxidase Subunit I (COI) and elongation factor-1 alpha (EF-1). The rooted trees showed several clusters for head chewing lice and this indicated that the phenomenon of parasitizing birds’ heads evolved several times in the clade of chewing louse. This is also indicating that the position on host played a very important role in shaping the diversity of these insects. The unrooted tree which produced by analysis of COI and (EF-1) also supports the previous conclusion but added to it the impact of host habitat on such diversity. The evolutionary distance between marine birds’ chewing lice was very small and all of them appear in single line or group which far from that of terrestrial taxa of the chewing lice. Both the host habitat and the feeding position of chewing lice on their hosts played a very important role in the way by which this group of insects evolved.