Morphological and molecular comparison of host‐derived populations of parasitic Psoroptes mites

Abstract

Infestation by parasitic Psoroptes mites (Acari: Psoroptidae) is an important cause of economic loss and welfare problems in livestock in many areas of the world. At least five species within this genus have been recognized, based on the host infested, the infestation site and differences in length of the opisthosomal setae of adult male mites. Here the integrity of these species is considered by subjecting populations of mites from a range of host species and geographical locations to simultaneous morphological and molecular genetic analyses. Morphological analysis showed that there were significant differences in shape and size between mite populations from different hosts, and that length of the outer opisthosomal setae in males and the homologous seta in females were the most important distinguishing character in adults. However, considerable variation in outer opisthosomal seta length was evident within and between populations of mites, and differences were not clearly related to host-species or geographical origin and did not support the accepted species differences. Molecular characterization using sequence data from the mitochondrial second internal transcribed spacer (ITS-2) region and microsatellite markers found little or no consistent host-related variation between the mite population samples. The results suggest that there is no case for considering the Psoroptes mites from the different hosts examined as separate species and that the morphological variation observed therefore may represent phenotypic adaptation to the local microenvironment on particular species of host.

DNA-barcoding contradicts morphology in quill mite species Torotrogla merulae and T. rubeculi (Prostigmata: Syringophilidae)

“…otsuka et al 1999, van Niekerk et al 2004, otranto et al 2005, Pegler et al 2005, Harper et al 2009, Vrijenhoek 2009, Wilson et al 2010.…”

Population identification and divergence threshold in Psoroptidae based on ribosomal ITS2 and mitochondrial COI genes

“…Thus, cross-contamination between species could not be avoided (Khaing et al 2014); (2) The gene used for molecular identification is usually single. Most studies involve the ITS2 gene (Zahler et al 1998;Essig et al 1999;Ochs et al 1999;Lohse et al 2002;Noge et al 2005;Pegler et al 2005;Hestvik et al 2007;Jia et al 2008), which cannot objectively reflect the evolution between species. The species evolution is imbalance for different genes based on the fact that rDNA ITS2 is not as good as mtDNA COI in the molecular classification and identification of Sarcoptes mites confirmed by our previous studies (Zhao et al 2015); (3) The mtDNA COI is the most common target gene used for identification at species level.…”

“…Several species that could not be classified based on morphology have now been categorized based on their DNA sequences. In Psoroptes, using ribosomal DNA internal transcribed spacers 2 (rDNA ITS2) as a molecular marker, it has been suggested that Psoroptes mites parasitizing domestic rabbit, sheep, alpaca, goat, cow, big-horn sheep, mule deer, elk, and white-tailed deer belong to the same species without host specificity (Pegler et al 2005). Using mitochondrial DNA cytochrome oxidase 1 (mtDNA COI) and 18S rDNA, Wang et al (2012) suggested that Psoroptes mites parasitizing buffalo belonged to a distinct species.…”

Isolation of Scopulariopsis spp. fungi from Psoroptes cuniculi body surface and evaluation of their entomopathogenic role

“…Among the five species of this genus (Sweatman 1958), Psoroptes ovis and Psoroptes cuniculi are of major veterinary importance (Wrenn 1996). Although there are some differences (Ochs et al 1999), at present, P. ovis and P. cuniculi are believed to be conspecific (Bates 1999;Zahler et al 1998Zahler et al , 2000Pegler et al 2005).…”