Phylogeny and host-parasite associations of feather mites of the Pteroherpus generic group (Astigmata: Pteronyssidae)

Cladistic reconstruction of phylogenetic relationships within the Pteroherpus generic group, consisting of the genera Dicrurobius, Micropteroherpus, Pteroherpus, and Vanginyssus, has been carried out, here, for the first time. This analysis was based on 46 morphological characters and 29 operational taxonomic units, including 21 species of the Pteroherpus group (ingroup), eight species representing three pteronyssid genera known from passeriforms and piciforms (close outgroups), and two species of the family Avenzoariidae (distant outgroups). Maximum parsimony analysis confirmed monophyly of the Pteroherpus group and four of its genera. The analysis also revealed four distinct lineages within the genus Pteroherpus that we treat as species groups: hoplophorus, diploplax, nicator, and josephi. The Pteroherpus group displays two contrasting tendencies in morphological modifications: (1) reduction of shield areas in the posterior part of the female opisthosoma by splitting the hysteronotal shield into fragments and decreasing their size; this trend has been realized to various extents in all genera of the group, and (2) development of additional sclerotization in the sejugal area in both sexes of the most derived species of the holoplax and diploplax groups of Pteroherpus. Based on phylogenetic relationships within the Pteroherpus generic group and among their avian hosts, and on parasite-host associations, we conclude that co-speciation with their hosts was the main mode of diversification although in a few cases host shift has taken place.