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Exotic mite taxa—Key feature pages

Prodorsal shield and setation

Most adult female mites have 4 pairs of legs (octopod), as do the nymphal stages, and only the larva (or prelarvaprelarva:
(also deutovum, prolarva) the first instar in acariform mites having a complete ontogenetic sequence, but absent in derived Prostigmata and Parasitiformes (except Opilioacarida); incompletely formed, without functional mouthparts, often retained within the egg shell or just extruding from it, and usually inactive; hexapod or apodous.
 when present) have 3 pairs of legs (hexapodhexapod:
with three pairs of legs (i.e. 6 legs), as in the larvae of mites or the larviform stages of others.
). Exceptions do occur, especially among the plant-parasitic mites.

  • The Penthaleidae (Eupodoidea) have a prodorsumprodorsum:
    the dorsal surface of the propodosoma.
     with 4 pairs of setae (sometimes with extra setae), including one pair formed as filiformfiliform:
    thread-like; long and narrow.
     or ciliated 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).
     (the internal scapular setaescapular seta:
    2 pairs of setae (sci, sce) on the prodorsum of Prostigmata, often inserted on either side of the eyes; see Vertical-scapular system.
    , sci) and a lobe over the capitulumgnathosoma:
    (= capitulum) the anteriormost part of a mite or ricinuleid, composed of the cheliceral and pedipalpal segments and separated from the body (idiosoma) by a ring of soft cuticle.
     called a naso that bears the internal vertical setae, vi.

  • Eriophyideriophyid:
    (eriophyoid) of or relating to a member of the family Eriophyidae (superfamily Eriophyoidea) which contains minute, worm-like and quadripod mites that cause galls, erinea, and other damage to plants.
     or diptilomiopid Eriophyoidea usually have a distinct prodorsal shieldprodorsal shield:
    a shield on the anterior dorsal surface of acariform mites.
     that is nude or bears only 1 pair of setae (the scapulars, sc). In the Phytoptidae, however, a single, unpaired median internal vertical seta (vi) or a pair of external vertical setae (ve)—or both are always present, with or without the presence of the scapular setaescapular seta:
    2 pairs of setae (sci, sce) on the prodorsum of Prostigmata, often inserted on either side of the eyes; see Vertical-scapular system.
     (sc).

  • Members of the Tetranychoidea usually have the basic 4 pairs of prodorsal setaeprodorsal setae:
    the setae on the prodorsum of acariform mites.  Two competing chaetotactic systems are used for designations: the Rostral-lamellar and Vertical-scapular systems.  
     (vi, ve, sci, sce), but some Tenuipalpidae have suppressed one of these pairs.

  • Adult female Tarsonemidae (TarsonemoideaTarsonemoidea:
    (also Tarsonemina) a superfamily within Prostigmata > infraorder Eleutherengona > hyporder Heterostigmata consisting of two families: Tarsonemidae and Podapolipidae.
    ) have 3 pairs of prodorsal setaeprodorsal setae:
    the setae on the prodorsum of acariform mites.  Two competing chaetotactic systems are used for designations: the Rostral-lamellar and Vertical-scapular systems.  
     (vi, sce, sci, while males have all 4 pairs), but appear to have only 2 pairs of prodorsal setaeprodorsal setae:
    the setae on the prodorsum of acariform mites.  Two competing chaetotactic systems are used for designations: the Rostral-lamellar and Vertical-scapular systems.  
    , because the capitiate 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) are usually placed under the margin of the prodorsumprodorsum:
    the dorsal surface of the propodosoma.
    . The external vertical setae (ve) are reduced to a pit. Both 2 and 4 pairs of prodorsal setaeprodorsal setae:
    the setae on the prodorsum of acariform mites.  Two competing chaetotactic systems are used for designations: the Rostral-lamellar and Vertical-scapular systems.  
     are accepted in this key if 'Mistakes allowed' (the default option) is turned on.

Feature pages