Home | Mesostigmata (Monogynaspida) Home | Glossary

Asca

Taxonomic Position

Cohort Gamasina

    Subcohort Dermanyssiae

Superfamily Ascoidea

Family: Ascidae Voigts & Oudemans

Subfamily: Ascinae

Asca von Heyden

 

Diagnostic characters:

Similar taxa. Antennoseius Berlese, Ectoantennoseius Walter, Gamasellodes Athias-Henriot, Protogamasellus Karg, and Diseius Lindquist & Evans lack horns.  Some Digamasellidae have horns, but also have sternal shields bearing setae st4.

 

Key to genera in the subfamily Ascinae

 

1.  With holodorsal shield that captures the R-series ..... 2

-   Dorsal shield divided into two subequal shields; R-series setae in soft cuticle ..... 3

2.  Seta z1 present laterad seta j1 on anterior median region of dorsal shield; femur III with 7 setae; genu I with 13 setae; tibia II with 10 setae ..... Orthadenella (Blattisociidae)

-    Seta z1 absent; femur III with 6 setae; genu I with 12 setae; tibia II with 9 setae ..... Neojordensia

3.   Opisthonotal shield with 12 pairs of setae (J3, Z2, S1 absent); podonotal shield lacking setae j2, z1, z3; adult leg setation strongly neotenous, genua I-II-III-IV with 11-8-7-7 setae, tibiae with 11-7-7-7 setae; female with anal shield ..... Diseius

-     Opisthonotal shield with 15 or more pairs of setae (J3, Z2, S1 present); podonotal shield with setae j2, z3, sometimes z1; adult leg setation not strongly neotenous, minimum number of setae on genua 12-11-8-8, on tibiae 13-10-8-9; female with anal or ventrianal shield ..... 4

4.   Hypostome with corniculi bifid apically; anterior rostral setae thickened, spinelike; dorsal shield setae z1 absent  ..... Anephiasca

-    Hypostome with corniculi entire apically; anterior rostral setae of similar thickness to other hypostomal setae; dorsal shield setae z1 present or absent ..... 5

5.   Female with epigynial shield strongly rounded posteriorly and with small subtriangular ventrianal or anal shield bearing 3-5 setae; male with ventrianal shield united to peritrematal shields; soft body cuticle often with microtuberculate striae ..... 6

-     Female with epigynial shield truncate posteriorly and usually with well developed ventrianal shield (rarely anal shield) bearing 3-9 setae (including circumanal setae); male with ventrianal shield separate from peritrematal shields; soft body cuticle striae without microtubercles ..... 8

6.   Palps elongated, at least half as long as leg I; palp trochanter longer than femur; palp tibia almost 3 times as long as tarsus ..... Anystipalpus

-     Palps of normal length, about one-third as long as leg I; palp trochanter slightly shorter than femur; palp tibia twice as long as tarsus ... 7

7.   Legs I with ambulacra and claws ..... Antennoseius (Vitzthumia)

-     Legs I with out ambulacra and claws ..... Antennoseius (Antennoseius)

8.    Opisthonotal shield with setae Z4 & S5 usually approximate and inserted together on pair of prominent posterolateral tubercles; podonotal shield lacking setae z1j2 well behind level of j1; peritrematal shields of adults broad, truncate posteriorly; genu I with 12 setae (av2 absent) ..... Asca

-     Opisthonotal shield with setae Z4, S5 well separated, not borne on pair of strong tubercles; podonotal shield with setae z1 present; j2 tending to be displaced anteriorly, often in approximately transverse row with z1 and j1; peritrematal shields of adults narrow or of moderate width, tapering posteriorly; genu I with 13 setae (av2 present) ..... 9

9.      Podonotal shield with transverse line extending across surface at level of setae z6, opisthonotal shield with similar line at level of setae J1; paranal setae inserted close to anterior margin of anus; genu IV with 8 setae (pl1 absent); tibia IV with 9 setae (pl2 absent) ..... Protogamasellus

-        Dorsal shields without transverse lines extending completely across surface; paranal setae inserted closer to posterior margin of anus than to anterior margin; genu IV with 9 setae (pl1 present); tibia IV with 10 setae (pl2 present) ..... 10

10.      Sternal pore 3 in soft cuticle; setae r3 and Z5 club-shaped, densely plumose; gnathotectum denticulate; movable digit of chelicerae serrate ..... Ectoantennoseius

-        Sternal pore 3 on sternal shield; setae r3 and Z5 setiform, smooth to barbed; gnathotectum more or less smoothly trifurcate; movable digit of chelicerae usually with 4-6 teeth, not serrate ..... Gamasellodes

 

References

Athias-Henriot C. 1969. Gamasides Chiliens (Acariens Anactinotriches). I - Genre Anephiasca n. g. (Ascidae). Revista de Biologia 7, 123-49

Champ BR. 1966. Insects and mites associated with stored products in Queensland. 4. Acarina and Pseudoscorpiones. Queensland Journal of Agricultural and Animal Sciences 23: 197-210.

Evans GO & 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.

Halliday RB, Walter DE & Lindquist EE. 1998. Revision of the Australian Ascidae (Acarina: Mesostigmata). Invertebrate Taxonomy 12: 1-54.

Hurlbutt HW. 1963. The genus Asca von Heyden (Acarina : Mesostigmata) in North America, Hawaii and Europe. Acarologia 5: 480-518.

Karg W. 1993. Acari (Acarina), Milben. Parasitiformes (Anactinochaeta). Cohors Gamasina Leach. Raubmilben. (Second Edition). Die Tierwelt Deutschlands 59: 1-523.

Kinnear A. 1991. Acarine communities of semi-arid soils from the Eastern Goldfields region of Western Australia. Pedobiologia 35: 273-83.

Kitching RL & Callaghan C. 1982. The fauna of water-filled tree holes in box forest in south-east Queensland. Australian Entomological Magazine 8: 61-70.

Krantz GW. 1962. Acari. Free-living Mesostigmata. II. The family Aceosejidae. Parc National de la Garamba. Mission H. de Saeger 34: 3-29.

Krantz GW. 1986. A Manual of Acarology. Second edition, 1978, emended 1986. (Oregon State University Book Stores, Corvallis, Oregon USA).

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

Lindquist EE. 1963. A taxonomic review of the genus Hoploseius Berlese (Acarina: Blattisocidae). Canadian Entomologist 95: 1175-85.

Lindquist EE. & Chant DA. 1964. A redescription of Aceodromus Muma and its transfer to the Blattisociinae (Acarina: Blattisociidae). Canadian Entomologist 96: 500-7.

Lindquist EE & Evans GO. 1965. Taxonomic concepts in the Ascidae, with a modified setal nomenclature for the idiosoma of the Gamasina (Acarina : Mesostigmata). Memoirs of the Entomological Society of Canada 47: 1-64.

Lindquist EE. & Walter DE. 1989. Biology and description of Antennoseius janus, new species (Mesostigmata: Ascidae), a mesostigmatic mite exhibiting adult female dimorphism. Canadian Journal of Zoology 67: 1291-1310.

Walter DE. 1998. Ectoantennoseius kitchingi, n. gen., n. sp. (Acari: Mesostigmata: Ascidae) from the rainforest canopy in Australia and a cladistic hypothesis about its relationships. International Journal of Acarology 24: 45-51.

Walter DE. 1998. Hoploseius australianus, sp. nov. (Acari: Mesostigmata: Ascidae), a unique element in the Australian acarofauna. The Australian Entomologist 25: 69-74.

Walter DE. 1987. Life history, trophic behavior and description of Gamasellodes vermivorax n. sp. (Mesostigmata: Ascidae) a predator of nematodes and arthropods in semiarid grasslands. Canadian Journal of Zoology 65: 1689-1695.

Walter DE, Halliday RB & Lindquist EE. 1993. A review of the genus Asca (Acarina: Ascidae) in Australia, with the description of three new leaf-inhabiting species. Invertebrate Taxonomy 7:1327-1347.

Walter DE & Ikonen EK. 1989. Species, guilds and functional groups: Taxonomy and behavior in nematophagous arthropods. Journal of Nematology 21: 315-327.

Walter, D.E. & Lindquist, E.E. 1989. Life history and behavior of ascid mites in the genus Lasioseius (Acari: Mesostigmata) from grassland soils in Colorado with taxonomic notes and a description of new species. Canadian Journal of Zoology 67: 2797-2813.

Walter DE. & Lindquist EE. 1995. The distribution of asexual ascid mites (Acari: Parasitiformes) does not support the biotic uncertainty hypothesis. Experimental & Applied Acarology 19: 423-442.

Walter DE. & Lindquist EE. 1997. Australian species of Lasioseius (Acari: Mesostigmata: Ascidae): the porulosus group and other species from rainforest canopies. Invertebrate Taxonomy 11: 525-547.

Walter DE. & Lindquist EE. (In press). Arrhenoseius gloriosus n. g., n. sp. (Acari: Mesostigmata: Ascidae), an arrhenotokous mite from rainforests in Queensland, Australia. Acarologia.