Taxonomic Position

Cohort Gamasina

Subcohort Dermanyssiae

    Superfamily Phytoseioidea

Phytoseiidae Berlese

Subfamily Amblyseiinae Muma 

Phytoseiulus Evans

(=Mesoseiulus Gonzalez & Schuster)

 

Diagnostic characters:

• Dorsal shield entire with 12-14 pairs of setae; present = j1, 3, 4, 5, 6; J5; z2, 4, 5; Z1, 4, 5; s4); j5, S5 present or absent (j1 absent on some individuals in cultures).

• Setae r3 and R1 present in the soft cuticle. 

• Setae Z1, Z4, Z5 and s4 along margin of dorsal shield very long and barbed. 

• Sternal shield with 2-3 pairs of setae, st4 +/- st3 on small plates. 

• Anal opening small, on anal (3 setae) or small ventrianal shield (4-5 setae). 

• Movable digit of chelicerae with 3 teeth, fixed digit chelate-serrate with 7-9 teeth or more stubby and chelate-dentate with only 3 teeth and terminal hook.

• Spermatheca funnel-like, either broadly tapering or with narrow neck and basal swelling.

• Tibia I setation: 2-2/2, 2/1-2

 

Similar taxa.  Ascids usually have dorsal shields with 22 or more pairs of setae.  Blattisociidae may have  have phytoseioid-like corniculi (e.g. Blattisocius), but usually have much fuller dorsal shield setation (Lasioseius phytoseioides group excepted).  Most other species of Amblyseiinae have ventrianal shields.

 

Ecology & Distribution. Species of Phytoseiulus are widely established around the world because of their use as biological control agents.  They are specialist predators of spider mites that produce dense webbing, especially species of Tetranychus.

        

References

Schicha e.  1987.  Phytoseiidae of Australia and Neighbouring Areas.  (Indira Publishing House, Oak Park, Michigan, USA.)

Schuster RO & Pritchard EA.  1963.  Phytoseiid mites of California.  Hilgardia 43: 191-285.

Takahashi F & Chant DA.  1993.  Phylogenetic relationships in the genus Phytoseiulus Evans (Acari: Phytoseiidae).  II. Taxonomic Review.  International Journal of Acarology 19: 23-37.

Tseng YH.  1976.  Systematics of the mite family Phytoseiidae from Taiwan, with a revised key to the genera of the world (II).  Journal of the Agricultural Association of China 94: 86-128. 

Evans, G. O., and Till, W. M.  1966.  Studies on the British Dermanyssidae (Acari: Mesostigmata).  Part II.  Classification.  Bull. Br. Mus. Nat. Hist. (Zool.) 14, 107-370.

Tenorio, J. M.  1982.  Hypoaspidinae (Acari: Gamasida: Laelapidae) of the Hawaiian Islands.  Pac. Insects 24, 259-274.

Wright, E.M., and Chambers, R.J..  1994. The biology of the predatory mite Hypoaspis miles (Acari: Laelapidae), a potential biological control agent of Bradysia paupera (Dipt.: Sciardiae).  Entomophaga 39, 225-235.

Womersley, H. 1956. On some new Acarina-Mesostigmata from Australia, New Zealand and New Guinea. J. Linn. Soc. (Zool.) 42, 505-599.

Zumpt, F., and Patterson, P. M.  1951.  Further notes on laelaptid mites parasitic on vertebrates.  A preliminary study to the Ethiopian fauna.  J. Entomol. Soc. Sth Afr. 14, 63-93.

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]

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

Walter DE, Campbell NJH.  2003.  Exotic vs endemic biocontrol agents: Would the real Stratiolaelaps miles (Berlese) (Acari: Mesostigmata: Laelapidae) please stand up?  Biological Control 26: 253-269.