| abstract | Ptyctimous mites ar erepresented in the Nearctic region by 108 species including 3 Protoplophoridae, 5 Mesoplophoridae, 40 Phthiracaroidea and 60 Euphthiracaroidea. Twenty species are newly discoverd Oribotritia cherokee sp.nov., Oribotritia henicos sp.nov., Oribotritia opipara sp.nov., Oribotritia oregonensis sp.nov., Mesotritia glabra sp.nov., Mesotritia minima sp.nov., Indotritia missouri sp.nov., Euphthiracarus parafusulus sp.nov., Euphthiracarus spinus sp.nov., Euphthiracarus vicinus sp.nov., Euphthiracarus virgatus sp.nov., Rhysotritia diaphoros sp.nov., Rhysotritia ornata sp.nov., Rhysotritia parareticulata sp.nov., Synichotritia longipila sp.nov., Synichotritia parvipilosa sp.nov., Protophthiracarus cavernosus sp.nov., Protophthiracarus texanus sp.nov., Atropacarus (Atropacarus) ciliosus sp.nov., Atropacarus (Atropacarus) multisetosus sp.nov. Morphological analysis has been performed for 71 types of species and subspecies described from the region. Twenty four species, mainly belonging to Euphthiracaroidea, have been redescribed. Nineteen synonyms have been found.
The most abundant and most frequently found species of the Euphthiracaroidea are the two widespread ones: Rhysotritia ardua (C. L. Koch, 1841) and Rhysotritia curticephala (Jacot, 1938). Widespread Phthiracaroidea include the Nearctic species Phthiracarus cognatus Niedbala, 1988 and the Holarctic Atropacarus (A.) striculus (C. L. Koch, 1835). Knowledge of the zoogeographical distribution of the species has been supplemented by many new localities. The ranges of 34 species have been proven to be greater than hitherto claimed.
The fauna of ptyctimous mites of the Nearctic region is highly specific. Nearly 70% (nearctic and endemic) of the species are restricted to the region, and the number of endemic species is relatively small. Nearctic species dominate in all subregions. There is a large number of widespread and pantropical species. Among the Euphthiracaroidea the contribution of endemic species is greater and that of the widespread species smaller than among the Phthiracaroidea. Only from among the Euphthiracaroidea have species originating probably from neotropic been identified. There is a large number of widespread continous species in the Nearctic region and a small number of endemic species. The typically Nearctic genera are Synichotrichia and Apotritia, while among the genera Oribotritia and Protophthiracarus only species restricted to Nearctic have been found. The Nearctic region is the centre of speciation of the genus Euphthiracarus, encompassing many species, mainly Nearctic elements. The abundant genus Phthiracarus is represented mainly by Nearctic species, although a large number of Holarctic species has been also found, which suggests a relation between the faunas of Nearctic and Palearctic.
The origin of the fauna studied is difficult to determine. Probably the ptyctimous mites of Nearctic are an ancient group developed independently from that of Palearctic and Neotropic, as indicated by a large number of species being nearctic and endemic elements, relative to a small number of holarctic species. The subgenus Steganacarus (Steganacarus), typical of the Ethiopian region and Mediterranean part of Palearctic does not occur in the Nearctic region. Also the genera Austrotritia, Notophthiracarus, Arphthicarus of gondwanian origin are not represented in the area. Another gondwanian genus, Austrophthiracarus is represented by only one species and the subgenus Atropacarus (Hoplophorella) by three widespread species. The ranges of a few species most probably of neotropical origin, reach their limits in Florida. |