Endeostigmata

t

Taxonomy

Sphaerolichidae Grandjean

Diagnosis

Prodorsumprodorsum:
the dorsal surface of the propodosoma.
with 2 pairs of filamentous trichobothriatrichobothrium:
(pl. trichobothria) (= bothridial sensillum) an often elaborately modified seta set in a cup-like base; forms include filiform, ciliate, pectinate or variously thickened or clubbed (bat-like to globose or capitate).
, 4 pairs of setaeseta:
(pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
, well developed naso (often with median eye on its underside), and usually a pair of lateral eyes +/- a pair of posteriorposterior:
the back part of the body or towards that region in comparison, e.g., 'posterior to'.
'ocular tubercles'. Subcapitulumsubcapitulum:
(also infracapitulum) the venter of the capitulum; the ventral faces of the fused palpcoxae; apparently formed independently in the two superorders of mites.
with 5 pairs of setaeseta:
(pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
; chelicerae chelatechelate:
pincer-like, as in a crab's claws, a scorpion's pedipalps or many chelicerae; in water mites (Hydrachnida), chelate palps have a dorsal palptibial process opposed to a ventral movable palptarsus (opposed to uncate).
, with 2 pairs of setaeseta:
(pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
, fixed digitfixed digit:
the distal extension of the middle article of the chelicera; usually bearing teeth and a distal hook and opposed to the movable digit in chelate-dentate forms, but often regressed; in Mesostigmata the fixed digit may bear the pilus dentilis.
with median process, movable digit bearing two lobe-like teeth; palps with 5 free segments. Bodybody:
the idiosoma of mites.
globular, with 8 pairs of dorsal setaeseta:
(pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
, c3–4, f3 absent; 5–7 pairs of genital setaeseta:
(pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
; 2 pairs of genital papillaegenital papillae:
 1-3 pairs of extrusible finger-like to button-like projections, usually retracted into in the genital vestibule of acariform mites; sometimes formed as sessile disks around the genital opening; thought to be osmoregulatory structures; modified or multiplied and dispersed over the body in many freshwater mites.  Genital papillae are absent in the larva, but may be added ontogenetically: protonymphs have one pair, deutonymphs two pairs, and tritonymphs (and adults) three pairs.  The tritonymphal pair of papillae is often lost.  The serially homologous Claparède's organ is usually present in the larvae (and prelarvae) of mites exhibiting genital papillae in nymphs and adults (Oudeman's Rule).
; eugenital setaeseta:
(pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
absent; 2–3 pairs of anal setaeseta:
(pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
; coxal bases continuous. Coxal fieldscoxal fields:
the venter of acariform mites where the coxae have fused to the body wall covering the sternal region.
I–IV contiguous; all pretarsi with paired claws, empodiaempodium:
(pl. empodia) an unpaired structure arising between the tarsal claws, ranging from pad-like to claw-like and often bearing structures such as tenent hairs, dense setulae, or taking the form of a featherclaw (Eriophyoidea)..
claw-like (II–III–IV), but absent from tarsustarsus:
(pl. tarsi) the subdistal leg segment between the tibia and the pretarsus (apotele).
I; front legs used as antennae and often bizarrely modified; tibiaetibia:
(pl. tibiae) the leg segment between the genu and the tarsus.
I with trichobothriatrichobothrium:
(pl. trichobothria) (= bothridial sensillum) an often elaborately modified seta set in a cup-like base; forms include filiform, ciliate, pectinate or variously thickened or clubbed (bat-like to globose or capitate).
.

Similar taxa

Grandjeanicus

Ecology and distribution

This genus is distinctive and common in many types of litter worldwide. Australian species of Sphaerolichus are a bright pink in colour in life and move slowly while waving the highly modified front legs. They climb readily and may be ambush predators (Walter unpublished), although South African species have been reported to contain fungal material (Theron 1979Theron 1979:
Theron PD. 1979. The functional morphology of the gnathosoma of some liquid and solid feeders in the Trombidiformes, Cryptostigmata and Astigmata (Acarina). pp. 575–579. In: Piffl E, ed. Proceedings of the 4th International Congress of Acarology. Akadémiai Kiadó, Budapest.).

References

• Kethley 1982dKethley 1982d:
  Kethley JB. 1982d. Endeostigmata. pp. 118-120. In: Parker SP, ed. Synopsis and classification of living organisms, Vol. 2. McGraw-Hill, New York.
• Kethley 1990aKethley 1990a:
  Kethley JB. 1990a. Acarina: Prostigmata (Actinedida). pp. 667-756. In: Dindal DL, ed. Soil biology guide. John Wiley & Sons, Brisbane.
• OConnor 1984cOConnor 1984c:
  OConnor BM. 1984c. 1. Speciation and evolution in Acari 1.2 Phylogenetic relationships among higher taxa in the Acariformes, with particular reference to the Astigmata. pp. 19-27. In: Griffiths DA and Bowman CE, eds. Acarology VI, Vol. I. Ellis Horwood Ltd, Chichester.
• Theron 1979Theron 1979:
  Theron PD. 1979. The functional morphology of the gnathosoma of some liquid and solid feeders in the Trombidiformes, Cryptostigmata and Astigmata (Acarina). pp. 575-579. In: Piffl E, ed. Proceedings of the 4th International Congress of Acarology. Akadémiai Kiadó, Budapest.
• Theron and Ryke 1975bTheron and Ryke 1975b:
  Theron PD and Ryke PAJ. 1975. Three new species of the family Sphaerolichidae (Acari: Endeostigmata) from South Africa. Acarologia 17: 220-235.
• Walter 1988cWalter 1988c:
  Walter DE. 1988c. Predation and mycophagy by endeostigmatid mites (Acariformes: Prostigmata). Experimental and Applied Acarology 4: 159-166.