Major mite taxa

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Taxonomy

updated 2025

Common names

whirligig mites, footballers, anystids, caeculids, red velvet mites, water mites, scrub itch mites, chiggers

Probability of encounter

high

Quarantine importance

General predators used in biological control occur in the Anystidae and some rarely bite people. Most Parasitengona are parasitic as larvae on insects, but Trombiculoidea attack vertebrates and may cause serious harm to livestock and wildlife through their feeding. Larval trombiculoids (chiggers) also attack people causing a nasty, but transient dermatitis (scrub itch) and may transmit rickettsia that cause scrub typhus.

Diagnosis

Anystina are small to large, subspherical to elongate mites with soft to heavily sclerotized bodies; purple, red, pink or brown in color. Cheliceral bases separate; fixed digit of chelicera reduced or absent, movable digit usually short and hooked. Palps usually raptorial with a well-developed claw-like seta on the tibia; development of the palp tarsus ranges from subterminal and thumb-like or button-like, to terminal, to absent. Peritremes well-developed and may be emergent or adherent to the prodorsal margin. Naso present or absent; one or two pairs of prodorsal trichobothria present; lateral eyes present or absent. Body setae range from short and scanty to long and hypertrichous; genital papillae usually present but often reduced in size and number.

Parasitengona are medium to very large; soft-bodied to heavily sclerotized; primarily red or orange but can be any color. Terrestrial species often conspicuously hypertrichous, displaying a velvety red pelage. Cheliceral bases separate; fixed digit of chelicera absent, movable digit hooked or linear. Palps often raptorial with a well-developed claw-like seta on the tibia; development of the palp tarsus ranges from subterminal and thumblike, to terminal, to absent. Gnathosoma retractile in some species. Stigmata and peritremes, when present, between the cheliceral bases. Terrestrial species usually with one or two pairs of prodorsal trichobothria, often mounted on a linear sclerotised plate (the crista metopica); eye lenses almost always well-developed. Genital papillae usually present but variable in size and number.

Similar taxa

Raphignathina lack prodorsal trichobothria.

Ecology and distribution

Most Anystides are thought to be predators of small arthropods. They are common in dry habitats, including deserts, where they are found in leaf litter and on rock surfaces, bark, and foliage. The Anystidae are known as 'whirligig mites' because of the rapid, spinning style of running exhibited by many species; some are useful biocontrol agents of mite and insect pests. The Caeculidae are also common in dry soils and in rocky habitats. These are distinctive sit-and-wait predators with massive spiny legs I; however, at least one species has been cultured on fungi. The Paratydeidae are small elongate mites with a distinctive idiosomal furrow posterior of legs IV. Their ecology is poorly understood. The same can be said of the less elongate Pseudocheylidae that are characteristic of dry soils. 

The Parasitengona are united on the basis of their complex life cycle. Larvae are parasites of invertebrates or vertebrates and are usually heteromorphic to the nymphal and adult stages. The predatory deutonymphal stage takes place in between the inactive pupa-like proto- and tritonymphal stages. Most postlarval Parasitengona are predators of small invertebrates, particularly arthropods, but a few species are parasitic as adults. The majority of the described species belong to the Hydrachnidiae, or 'water mites'. The approximately 2,000 named species of terrestrial Parasitengona fall into two groups: the Erythraiae, which have chelicerae that can be retracted within the idiosoma; and the Trombidiae, which have non-retractable chelicerae. Members of both groups are often large (5–8 mm), bright red and furry, resulting in the common name 'velvet mites'. They are abundant and diverse inhabitants of leaf litter, moss, the upper layers of soil, and foliage. The families Leeuwenhoekiidae and Trombiculidae are the well known chiggers.

References

• Coineau 1973Coineau 1973:
  Coineau Y. 1973. Les Caeculidae (Acariens Prostigmates) quelques aspects de leurs particularités éco-éthologiques. Bulletin de la Société d'Écologie IV (4): 329–337.
• Kethley 1990aKethley 1990a:
  Kethley JB. 1990a. Acarina: Prostigmata (Actinedida). pp. 667–756. In: Dindal DL, ed. Soil biology guide. John Wiley & Sons, Brisbane.
• Krantz 1978Krantz 1978:
  Krantz GW. 1978. A manual of acarology [2nd ed.]. Oregon State University Book Stores, Corvallis.
• Harvey 1998Harvey 1998:
  Harvey MS. 1998. The Australian water mites: A guide to the families and genera. Monographs on Invertebrate Taxonomy, Vol. 4. CSIRO Publishing, Collingwood.
• Otto 1999Otto 1999:
  Otto JC. 1999. Revision of the genus Erythracarus Berlese (Acarina: Anystidae: Erythracarinae). Journal of Natural History 33: 825–909.
• Proctor et al. 1998Proctor et al. 1998:
  Proctor HC, Harvey M, Walter D, Mckie B. 1998. Key to freshwater arachnids (spiders and mites) of Australia [Lucid multimedia key]. In: An Interactive Guide to Australian Aquatic Invertebrates (Windows ed. 2). CSIRO Publishing, Collingwood. (Original work published on CD-ROM)
• Southcott 1961Southcott 1961:
  Southcott RV. 1961. Studies on the systematics and biology of the Erythraeoidea (Acarina), with a critical revision of the genera and subfamilies. Australian Journal of Zoology 9: 367–610.
• Southcott 1986Southcott 1986:
  Southcott RV. 1986. Studies on the taxonomy and biology of the subfamily Trombidiinae (Acarina: Trombidiidae) with a critical revision of the genera. Australian Journal of Zoology Supplementary Series 123: 1–116.
• Southcott 1987Southcott 1987:
  Southcott RV. 1987. The classification of the mite families Trombellidae and Johnstonianidae and related groups, with the description of a new larva (Acarina: Trombellidae: Nothotrombidium) from North America. Transactions of the Royal Society of South Australia 111: 25–42.
• Walter and Proctor 1999Walter and Proctor 1999:
  Walter DE, Proctor HC. 1999. Mites: Ecology, evolution and behaviour. University of NSW Press, Sydney and CABI, Wallingford. 494 pp.
• Welbourn 1991Welbourn 1991:
  Welbourn WC. 1991. Phylogenetic studies of the terrestrial Parasitengona. pp. 163–170. In: Dusbabek F and Bukva V, eds. Modern Acarology, Vol. 2. Academia, Prague and SPB Academic Publishing, The Hague.