Endeostigmata

t

Taxonomy

Alycidae Canestrini & Fanzago 1877 (=Pachygnathidae Kramer 1877, Bimichaeliidae Womersley 1944Womersley 1944:
Womersley H. 1944. Australian Acarina, families Alycidae and Nanorchestidae. Transactions of the Royal Society of South Australia 68: 133–143.)

Diagnosis

Prodorsumprodorsum:
the dorsal surface of the propodosoma.
with posteriorposterior:
the back part of the body or towards that region in comparison, e.g., 'posterior to'.
pair of 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 = bo) capitatecapitate:
with a terminal knob or head-like swelling; clavate; globose.
and anterioranterior:
the front part of the body or towards that region in comparison, e.g., 'anterior to'.
pair (ve = le) filiformfiliform:
thread-like; long and narrow.
and with 4 or more pairs of barbed to stellate 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.
(prodorsal hypertrichy sometimes present); naso with median eye; lateral eyes absent. 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.
present; chelicerae attenuate-edentateedentate:
with out teeth; usually referring to chelicerae.
(stylet-likestylet-like:
referring to chelicerae or movable digits that are slender, elongate, and usually acuminate.  Stylet-like chelicerae may be composed of the entire chelicera (as in some parasitic Dermanyssoidea or the endeostigmatan genus Bimichaelia) or only the movable digits (as in many Prostigmata).  If the cheliceral stylets are especially elongate, they may be called whip-like stylets (e.g., in spider mites and their relatives).
) and nude. Opisthosomaopisthosoma:
(= abdomen) the posterior body division in arachnids; usually not distinct in mites because of the fusion of the opisthosoma with part of the prosoma to form the idiosoma.
usually hypertrichous and often with stellatestellate:
star-like.  
integument; 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).
. Leg IV not modified for jumping.

Remarks

These are among the most common and largest of endeostigmatans found in forest soil and litter and are also common in grasslands. Nothing is known about their biology, but because of their stylet-likestylet-like:
referring to chelicerae or movable digits that are slender, elongate, and usually acuminate.  Stylet-like chelicerae may be composed of the entire chelicera (as in some parasitic Dermanyssoidea or the endeostigmatan genus Bimichaelia) or only the movable digits (as in many Prostigmata).  If the cheliceral stylets are especially elongate, they may be called whip-like stylets (e.g., in spider mites and their relatives).
mouthparts, some authors have suggested that they may feed on plant roots or mycorrhizae.

Similar taxa

Species of Petralycus have the anterior pair of trichobothria capitate and the posterior pair filiform.

References

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