Taxonomic Position

Cohort Gamasina

Subcohort Epicriiae

    Superfamily Zerconoidea 

Family: Zerconidae Berlese

Acoesejus Sellnick, Aleksozercon Petrova, Allozercon Blaszak, Amerozercon Halaskova, Aquilonozercon Halaskova, Aspar Halaskova, Bakeras Blaszak, Bledas Halaskova, Carpathozercon Balan, Caurozercon Halaskova, Cosmozercon Blaszak, Echinozercon Blaszak, Eurozercon Halaskova, Hypozercon Blaszak, Icozercon Blaszak, Indozercon Blaszak, Kaikiozercon Halaskova, Koreozercon Halaskova, Krantzas Blaszak, Lindquistas Blaszak, Macrozercon Blaszak, Mesozercon Blaszak, Metazercon Blaszak, Microzercon Blaszak, Mixozercon Halaskova, Monozercon Blaszak, Neozercon Petrova, Paleozercon Blaszak, Cokendolpher & Polyak, Parazercon Trägårdh, Parhozercon Blaszak, Polonozercon Blaszak, Prozercon Sellnick, Rafas Blaszak, Skeironozercon Halaskova, Syskenozercon Athias-Henriot, Triangulazercon Jacot, Trizerconoides Jacot, Xenozercon Blaszak, Zercon Koch

 

Diagnostic characters:

• Adults with 2 dorsal shields, each with serrate to crenulate margins with interspersed marginal setae and usually with 4 deep semi-circular depressions (fossae) on the posterior shield

• Peritrematal shields broad, bearing 1-3 pairs of setae

• Peritremes typically short in adults, often comma-shaped

• Euanal setae may be present.

 

Similar taxa. Heatherellidae have elaborate setae on the margins of the their shields, but also have large, spout-like gland openings and subdivided opisthonotal shielding.  Some ascids (Ascinae) may seem superficially similar to zerconids, but lack deep pits and serrate margins on the dorsal shield, as well as having a reduced chaetotaxy, seta JV5 fully ventral, and a dermanyssine reproductive system.  Adult female Coprozercon (Coprozerconidae) lack a opisthonotal shield.

 

Diagnosis. Brown, yellow or pinkish, oval to subrectangular mites with separate podonotal and opisthosomal shields usually bearing r-R series and often with serrate margins; often somewhat hypertrichous; podonotal shield usually with 4 deep depressions near its posterior margin at the insertion of major dorso-ventral muscles, and bearing ventral seta JV5.  Female sternal shield with 3 pairs of setae (st1-3) and 2 pairs of lyrifissures (stp1-2); st4 and stp3 usually on small metasternal platelets; epigynial shield axe-shape, with 1 pair of setae; inguinal glands on small platelets between base of epigynial shield and coxae IV or in soft cuticle; anal opening with 2 valves (often with a pair of euanal setae) in large ventrianal shield, free from truncate peritrematal shield or fused to peritrematal-metapodal shields.  Peritremes usually short in adults (< anterior margin of coxa II), but longer in deutonymphs, on broad shields bearing 1-3 pairs of setae.  Tarsus I with claws.  Palp genu with 6 setae; palp apotele with 2 tines.  Tectum denticulate to spinose; subcapitular gutter often with pencil-like rows of ridges;  corniculi horn-like; hypostomal setae in triangular array; hypostomal groove broad, with denticles.  Chelicerae chelate-dentate; pilus dentilis setiform.  Male genital opening on intercoxal shield, valve with a pair of setae; neither chelicerae nor legs obviously modified for sperm transfer.

 

References

Blazak C.  1974.  Zerconidae (Acari, Mesostigmata) Polski.  Monografie Fauny Pol. 3: 315 pp.

Blazak C, Cokendolpher JC, and Polyak VJ.  1995.  Paleozercon cavernicolous, n. gen., n. sp., fossil mite from a cave in the southwestern USA (Acari, Gamasida: Zerconidae), with a key to Nearctic genera of Zerconidae.  International Journal of Acarology 21: 253-259.

Evans EO and Till WM.  1979.  Mesostigmatic mites of Britain and Ireland (Chelicerata: Acari-Parasitiformes).  An introduction to their external morphology and classification.  Transactions of the Zoological Society of London 35 (2): 145-270.

Halaskova V.  1969.  Zerconidae of Czechoslovakia (Acari: Mesostigmata).  Acta Univ. Carol. (Biologica) 3, 4: 175-352.

Gilyarov MS & Bregatova NG (eds)  1977.  Handbook for the Identification of Soil-inhabiting Mites, Mesostigmata.  Zoological Institute of the Academy of Sciences: Petrograd [In Russian]

Johnston, D.E.  1982.  Mesostigmata.  In: Parker, S.P. (ed.)  Synopsis and classification of living organisms.  McGraw-Hill, New York, p. 112-116.

Krantz GW.  1978.  A Manual of Acarology.  OSU Bookstores: Corvallis.

Krantz, GW & Ainscough, B.  1990.  Mesostigmata.  pp. 583-665, in DL Dindal (ed) Soil Biology Guide.  John Wiley & Sons: Brisbane.

Moraza ML and Lindquist EE.  2000.  Coprozerconidae, a new family of zerconoid mites from North America.  Acarologia in press.

Walter, D.E.  1988a.  Nematophagy by soil arthropods from the shortgrass steppe, Chihuahuan desert, and Rocky Mountains of the central United States.  Agriculture, Ecosystems & Environment 24: 307-316.