New observations on phylogeny of cheyletoid mites (Acari: Prostigmata: Cheyletoidea)

Abstract

The mite superfamily Cheyletoidea (Acari: Prostigmata) includes 5 families: Cheyletidae, Syringophilidae, Harpirhynchidae (including Ophioptinae), Psorergatidae, and Demodicidae. A new hypothesis of cheyletoid phylogeny was carried out with maximum parsimony approach. Raphignathus collegiatus (Raphignathidae) and Storchia robusta (Stigmaeidae) were selected as outgroups. Cheyletoid ingroup species are represented by Eucheyletia asiatica and Cheyletiella parasitivorax (Cheyletidae), Syringophilus bipectinatus and Picobia sturni (Syringophilidae), Harpyrhynchoides columbae, Harpypalpus holopus and Ophioptes parkeri (Harpirhynchidae), Psorobia foinae (Psorergatidae), and Demodex folliculorum (Demodicidae). These species exhibit most characters observed in cheyletoid mites. Their character states were selected on the basis of strong a priori evidence of their being stable or ancestral in respective families or subfamilies. In total, 11 terminal taxa and 127 characters (11 autapomorphies) were included in the analysis. All characters were unordered and unweighted. The exact search option (Branch and Bound) was used. Supports for branches were estimated by Bremer support indices (BS). A single tree revealing the superfamily Cheyletoidea as a monophyletic group (BS 8) splitting onto 2 main lineages was obtained. Lineage I (BS 1): Cheyletidae (BS 2) – Syringophilidae (BS 2); lineage II (BS 15): Harpirhynchidae (BS 3) (Psorergatidae-Demodicidae) (BS 23). The reciprocal exchange of outgroup positions showed the same result. The topology of obtained cladogram corresponds to the phylogenetic hypothesis proposed earlier (Bochkov 2002) with exception for the branch bearing the families Epimyodicidae and Cloacaridae, because they were recently excluded from the superfamily (Bochkov and OConnor 2008).