Endeostigmata

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Taxonomy

Terpnacaridae Grandjean, 1939Grandjean, 1939:
Grandjean F. 1939. Quelques genres d’acariens appartenant au groupe des Endeostigmata. Annales des Sciences Naturelles, Zoologie 11 (ser. 2): 1–122.

Diagnosis

Prodorsumprodorsum:
the dorsal surface of the propodosoma.
with 1 pair of filiform 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).
(bo) and 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.
, mostly expanded to foliosefoliose:
leaf-like; usually describing flattened, oval to rectangular setae with or without other ornamentation.
; naso well developed and bearing setae ro, and on its underside, the median eye; lateral eyes absent. 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 5–6 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.
; rutellarutellum:
(pl. rutella) In Sarcoptiformes, the hypertrophied setae on the hypostome, often toothed; not to be confused with a corniculus (although possibly a homologue).  In Astigmata, the rutellum may be referred to as a pseudorutellum, although it is the same structure.  Various forms of rutella are recognized, including the atelebasic and pantelebasic.
slender, with distaldistal:
towards the free end of an appendage.
shear-like blade; chelicerae chelate-dentatechelate-dentate:
pincer-like chelicerae with teeth.
, each with 2 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.
. Adults with 28–35 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.
on segments C–PA, mostly expanded, foliosefoliose:
leaf-like; usually describing flattened, oval to rectangular setae with or without other ornamentation.
or subrectangular; 10–16 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.
in 2 rows; 3 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).
; ovipositorovipositor:
an extrusible organ for laying eggs.  Female oribatids have a well developed ovipositor that ends in three finger-like projections.  Ovipositors are less well developed or absent in other mites.
, 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.
present. All pretarsi with a pair of simplesimple:
unadorned; simple setae are needle-like and without hairs or pectins.
claws and a clawclaw:
like - having a distal hook; resembling a claw.
-like empodiumempodium:
(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)..
with a setulate (rayed) basebase:
the usually columnar basal part of the tritosternum; sometimes expanded and rectangular or otherwise modified; the most basal part of any structure.
. Gut boluses with fungal hyphae and spores. No males described.

Remarks

Little is known about these extremely tiny but ornately ornamented mites.

References

• Grandjean 1939Grandjean 1939:
  Grandjean F. 1939. Quelques genres d’acariens appartenant au groupe des Endeostigmata. Annales des Sciences Naturelles, Zoologie 11 (ser. 2): 1-122.
• 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.
• Theron 1976Theron 1976:
  Theron PD. 1976. Three new species of the genus Alycosmesis (Acari: Terpnacaridae) from South Africa. Journal of the Entomological Society of Southern Africa 38: 289-296.