Parasitiformes

Introduction

The Parasitiformes is one of the three major lineages of chelicerate arthropods that are called mites. Ticks are among the most economically important parasitiform mites, but numerous Mesostigmata, especially in the Dermanyssoidea are also debilitating parasites of mammals, birds, and reptiles. The phytoseiid mites used in biological control belong to the Mesostigmata, as do numerous species of predators that inhabit soil-litter systems. Currently, both the Ixodida (ticks) and Holothyrida consist of three families; the Mesostigmata contains approximately 70 family-level taxa.

Characteristics

Parasitiform mites have free coxae, a ventral anal opening covered by a pair of plates, corniculli on the hypostome (lost in ticks), a sclerotised ring surrounding the gnathosoma (capitulum), and usually a biflagellate tritosternum (lost in ticks, many holothyrids, and some parasitic Mesostigmata).

Discussion of Phylogenetic Relationships

The hypothesis by Lehtinen (1991) supports a sistergroup relationship between Holothyrida and Ixodida; however, other acarologists have suggested that ticks and Mesostigmata are sistergroups. Phylogenetic analyses addressing the proper placement of ticks are underway in Queensland and Ohio.

Other Names for Parasitiformes

• Holothyrans, ticks and mesostigmatic mites

References

Lehtinen, P.T. 1991. Phylogeny and zoogeography of the Holothyrida. In: Dusabek, F. and Bukva, V. (eds.) Modern Acarology, Volume 2. SPB Academic Publishers, The Hague, pp. 101-113.

Title Illustrations

SEM of Allothyrus sp. from Queensland (D.E. Walter)

About This Page

University of Alberta, Edmonton, Alberta, Canada

Correspondence regarding this page should be directed to David Evans Walter at

Page copyright © 1996

Page: Tree of Life Parasitiformes. Holothyrans, ticks and mesostigmatic mites. Authored by David Evans Walter. The TEXT of this page is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.

• First online 13 December 1996
• Content changed 13 December 1996