Endeostigmata

t

Taxonomy

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).
(sci) 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.
; naso well developed and bearing setae vi; median and lateral eyes absent. Subcapitulum with 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.
teeth; chelicerae chelate-dentatechelate-dentate:
pincer-like chelicerae with teeth.
, each with one setaseta:
(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.
. Opisthosomal setalsetal:
of or pertaining to a seta.
rows C–D–E–F–H–PS–AD–AN with 4–2–2–3–3–3–4–4 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.
, respectively; PA absent. Genital flaps with 7–10 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.
in 2 rows; 2–3 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).
in adult. All pretarsi with a simplesimple:
unadorned; simple setae are needle-like and without hairs or pectins.
, 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)..
; lateral claws absent. Gut boluses composed of fungal hyphae, spores, and bits of small, soft-bodied invertebrates.

Remarks

Alicorhagia fragilis is omnivorous and readily preys on nematodes. Larvae, protonymphs and deutonymphs spin silken webs before moulting (tritonymphs do not occur). The thelytokousthelytokous:
exhibiting all female parthenogenesis (thelytoky).
females spin silken webs on which the eggs are laid and hatch into an elattostaticelattostase:
(adj. elattostatic) one of the abnormal stases recognized by Grandjean where the mouthparts are not functional but the legs are, e.g., prelarvae of some Anystina and Nanorchestidae; the deutonymph in Astigmata.
prelarva (Walter 1988cWalter 1988c:
Walter DE. 1988c. Predation and mycophagy by endeostigmatid mites (Acariformes: Prostigmata). Experimental and Applied Acarology 4: 159-166.). It’s not clear that the mite so beautifully illustrated by Grandjean is the same as Berlese’s species; however, A. fragilis appears to be widely distributed in the Northern Hemisphere and A. usitata in the Southern Hemisphere.

References

• Evans 1992Evans 1992:
  Evans GO. 1992. Principles of Acarology. CAB International, Wallingford, UK.
• 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.
• Halliday 1998Halliday 1998:
  Halliday B. 1998. Mites of Australia: A checklist and bibliography. Monographs on Invertebrate Taxonomy, Vol. 5. CSIRO Publishing, Collingwood.
• Hirst 1923Hirst 1923:
  Hirst S. 1923. On some arachnid remains from the Old Red Sandstone. Annals and Magazine of Natural History (9th series) 12: 455-474.
• 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.
• Kethley et al. 1989Kethley et al. 1989:
  Kethley JB, Norton RA, Bonamo PM, and Shear WA. 1989. A terrestrial alicorhagiid mite (Acari: Acariformes) from the Devonian of New York. Micropaleontology 35: 367-373.
• Livshits and Mitrofanov 1978aLivshits and Mitrofanov 1978a:
  Livshits IZ and Mitrofanov VI. 1978a. Alicorhagiidae. pp. 97-98. In: Gilyarov MS, ed. Identification key of soil-inhabiting mites, Trombidiformes. Nauka, Moscow.
• Norton et al. 1993Norton et al. 1993:
  Norton RA, Kethley JB, Johnston DE, and O'Connor BM. 1993. Phylogenetic perspectives on genetic systems and reproductive modes of mites. pp. 8-99. In: Wrensch DA and Ebbert MA, eds. Evolution and diversity of sex ratio in insects and mites. Chapman and Hall, New York.
• 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 et al. 1970Theron et al. 1970:
  Theron PD, Meyer MKP, and Ryke PAJ. 1970. The family Alicorhagiidae Grandjean (Acari: Trombidiformes) with descriptions of a new genus and species from South African soils. Acarologia 12: 668-676.
• Walter 1988cWalter 1988c:
  Walter DE. 1988c. Predation and mycophagy by endeostigmatid mites (Acariformes: Prostigmata). Experimental and Applied Acarology 4: 159-166.
• Walter and Proctor 1999Walter and Proctor 1999:
  Walter DE and Proctor HC. 1999. Mites: Ecology, evolution and behaviour. University of NSW Press, Sydney and CABI, Wallingford. 494 pp.
• Zacharda 1978Zacharda 1978:
  Zacharda M. 1978. Terrestrial prostigmatic mites from the Amateur’s Cave, the Moravian Kars, Czechoslovakia. Vestnik Ceskoslovnské Spolecnosti Zoologické 42: 215-240.