Taxonomic Position

Cohort Gamasina

Subcohort Arctacariae

Arctacaridae Evans 1955:295

Arctacarus Evans 1955:299

Diagnostic characters:

• Adult females with a truncate dorsal shield extending somewhat onto the opisthonotal region

• A median double-oval (lazy-8) posterior pygidial sclerite

• Chelicerae enlarged and with a bifurcate pilus dentilis.

 

Similar taxa in key. Species of Proarctacarus have a very short podonotal shield and a series of small mesonotal platelets.  Laelapidae (Hypoaspis, Geolaelaps), Parasitidae, Veigaiidae all are somewhat similar in form to Arctacarus, but none have the posteriorly truncate dorsal shield, lazy-8 pygidium, and bifurcate pilus dentilis, nor males with a mid-coxal genital opening.

 

Known species:

Arctacarus rostratus Evans 1955 [Type]

Arctacarus beringianus Bregetova 1977

Arctacarus dzungaricus Bregetova 1977  

Diagnosis.  Brown and white, with truncate dorsal shield exposing much of opisthosoma of female; opisthonotal region with pairs of small mesonotal scutella and a minute, lazy-8 shaped pygidial sclerite.  Sternal shield large, with 3 pairs of setae (st1-3), 3 pairs of lyrifissures (stp1-3), and fused endopodal elements I-II; st4 in soft cuticle; genital shield axe-shape, nude, flanked by 2 pairs of setae in soft cuticle; inguinal glands on small platelets behind coxae IV; anal opening with 2 valves in small anal shield.  Peritremes relatively short, reaching anterior margin of coxa II, peritrematal shield poorly developed and fused to dorsal shield anteriorly.  Tarsus I with or without claws.  Palp genu with 6 setae; palp apotele with 3 tines.  Tectum mucronate and coarsely denticulate; hypostomal setae in triangular array; subcapitular gutter broad, with denticles; corniculi horn-like.  Chelicerae chelate-dentate to chelate serrate; pilus dentilis short, broad and bifurcate.  Male with holodorsal shield; genital opening on intercoxal shield, valve with a pair of setae; chelicerae not obviously modified for sperm transfer, but legs II and IV with spurs.

 

References

Bregetova, N.G. 1977.  Fam. Arctacaridae Evans, 1955.  In: (Gilyarov, M.S. and N.G. Bregetova eds.)  Key to Soil-inhabiting Mites. Mesostigmata.  Nauka, Leningrad  pp. 145-148. [In Russian]

Evans EO.  1955.  A collection of mesostigmatid mites from Alaska.  Bulletin of the British Museum (Natural History) [Zool.] 2: 285-307.

Makarova, O.L. 2003.  New genus and three new species of mites of the family Arctacaridae (Parasitiformes; Mesostigmata) from North America.  Zool. Zh. 82: 919-936. [In Russian]