Taxonomic Position

Cohort Gamasina

    Subcohort Dermanyssiae

  Superfamily Phytoseioidea

 

Family: Blattisociidae

Subfamily Platyseiinae (formerly Ascidae, Platyseiinae)

Cheiroseiulus Evans & Baker

 

Diagnostic characters:

• Opisthonotal region of dorsal shield with only 5  pairs of setae and J1-4 missing

• Female without metasternal plates and with anal shield

• Male without metasternal setae

• Median lobes of pulvillus of legs II-IV acute

• Genu II with 9 setae (pl2 absent)

• Paranal setae inserted slightly anterior to posterior margin of anal opening

• Legs II-IV with median lobe of pulvillus blunt

• Anterior rostral and internal palp trochanter setae extremely long, whip-like, tapering only near tip

• Phytoseiid-type sperm access system

• Fixed cheliceral digit with a deep receptacle that receives the tip of the movable digit;

• Male lacking metasternal setae

• Post-stigmatic peritrematal extension absent.

Key to females of genera of Platyseiinae

1.     Opisthonotal region of dorsal shield markedly hypotrichous, with only 5 pairs of setae (Z1, Z4, Z5, S4, J5); sternal setae st4 in soft cuticle; with anal shield; median lobes of pulvillus of legs II-IV blunt; ........................ Cheiroseiulus

-     Opisthonotal region of dorsal shield with 12-15 pairs of setae; with metasternal plates bearing st4 and ventrianal shield; median lobes of pulvillus of legs II-IV acute; ..................................................2

2.   Opisthonotal region of dorsal shield with 2-4 pairs of setae in J-series; first pair of sternal setae (st1) distinctly shorter than third pair (st3); distance between fifth and sixth rows of deutosternal denticles nearly twice that between fourth and fifth rows; tibia II with 9 setae (pd1 absent) ......................... Platyseius

-     Opisthonotal region of dorsal shield with 5 pairs of setae in J-series; 1st and 3rd pairs of sternal setae subequal in length; distance between 5th and 6th rows of deutosternal denticles similar to that between 4th and 5th rows; tibia II with 10 setae (pd1 present)..........................................Cheiroseius

 

 

Ecology & Distribution.  Cheiroseiulus reniformis Evans & Baker was collected from a phytotel, a water-filled epiphyte.

 

References

Evans, G.O. and Baker, A.  1991.   A new genus of the mite subfamily Platyseiinae from Jamaica (Parasitiformes: Ascidae). Journal of Zoology-(London) 224(1): 121-126.

Evans, G. O. and Hyatt, K. H. 1960. A revision of the Platyseiinae (Mesostigmata: Aceosejidae) based on material in the collections of the British Museum (Natural History). Bulletin of the British Museum (Natural History) Zoology 6 (2) : 27-101.

Evans EO & 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.

Karg W. 1993. Acari (Acarina), Milben. Parasitiformes (Anactinochaeta). Cohors Gamasina Leach. Raubmilben. (Second Edition). Die Tierwelt Deutschlands 59: 1-523.3.

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, E.E.  2003.  Observations on mites of the subfamily Platyseiinae, with descriptions of two new species of Platyseius from North America (Acari: Mesostigmata: Ascidae).  pp. 155-182 in Smith, Ian M. [Ed.]. An acarological tribute to David R. Cook. Indira Publishing House, West Bloomfield.