Mesostigmata

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Taxonomy

updated 2025

Diagnostic characters

• Hypertrichous dermanyssoiddermanyssoid:
  a member of the Dermanyssoidea (Mesostigmata).  Most dermanyssoids are parasitic on vertebrates, but some (e.g., species of Varroa, Tropilaelaps) are parasites of honeybees or other insects.  Members of the Hypoaspidinae (=Hypoaspididae) are primarily free-living predators including species useful in biocontrol in the genera Geolaelaps, Stratiolaelaps, and 'Hypoaspis'.
  mites with very long, 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).
  chelcerae
• Dorsaldorsal:
  relating to the upper or back side; opposed to ventral.
  shield entireentire:
  a shield or sclerite with a continuous margin without incisions.
  or with a single posterior scutellascutella:
  (pl scutellae) small shields or platelets.
  
• Sternal shieldsternal shield:
  a shield in the anterior intercoxal region of parasitiform mites that bears one or more pairs of sternal setae.
  bearing 3 pairs of setae; anal shield relatively large; genital shieldgenital shield:
  a shield or shields covering the genital opening; in female mongynaspine Mesostigmata this shield is usually called the epigynal (epigynial) shield.  
  tongue- to dagger-shaped and bearing 1 pair of setae.
• Peritremes very short or reaching to anterior margin of coxae II
• Tritosternumtritosternum:
  the sternum of the 3rd body segment (between legs I); produced as a biflagellate structure in Mesostigmata, although sometimes the flagellae (laciniae) are partially or completely fused.  
  biflagellate; seta j3 present.

1. Dorsaldorsal:
   relating to the upper or back side; opposed to ventral.
   shield relatively long, without pygidial plate; genital shieldgenital shield:
   a shield or shields covering the genital opening; in female mongynaspine Mesostigmata this shield is usually called the epigynal (epigynial) shield.  
   broadly tongue-shaped.............................. L. intermedius (Evans & Till)
2. Dorsaldorsal:
   relating to the upper or back side; opposed to ventral.
   shield strongly taperingtapering:
   drawn out or with margins converging.
   , with separate pygidial plate; genital shieldgenital shield:
   a shield or shields covering the genital opening; in female mongynaspine Mesostigmata this shield is usually called the epigynal (epigynial) shield.  
   dagger-shaped.............................. L. sanguineus (Hirst)

Similar taxa

Macronyssidae, Dermanyssus

Ecology and distribution

Blood-feeding parasites of vertebrates. Liponyssoides sanguineus (Hirst) feeds on mice, and to a lesser extent other rodents, and is a known vector of rickettsial pox.

References

• Evans and Till 1966Evans and Till 1966:
  Evans GO and Till WM. 1966. Studies on the British Dermanyssidae (Acari: Mesostigmata). Part II. Classification. Bulletin of the British Museum (Natural History) Zoology 14: 107-370.
• Moss 1968Moss 1968:
  Moss WW. 1968. An illustrated key to the species of the acarine genus Dermanyssus (Mesostigmata: Laelapoidea: Dermanyssidae). Journal of Medical Entomology 5: 67-84.