Stratiolaelaps

t

Taxonomy

Stratiolaelaps womersleyi Walter & Campbell

Diagnostic characters

Lamington-group species (posteriorposterior:
the back part of the body or towards that region in comparison, e.g., 'posterior to'.
margin of sternal shieldsternal shield:
a shield in the anterior intercoxal region of parasitiform mites that bears one or more pairs of sternal setae.
concave, gnathotectumgnathotectum:
(= epistome, tectum) an often membranous dorsal projection of the anterior margin of the basis capitulum in Mesostigmata; often diagnostic at family-, genus- or species-levels; also often difficult to see without high magnification and good optics.
with median and lateral processes) with serrateserrate:
with closely set teeth that resemble the cutting edge of a saw.
fixed cheliceralcheliceral:
of or pertaining to the chelicera.
digit, genital setaeseta:
(pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
(st5) inserted on margin of genital shieldgenital shield:
a shield or shields covering the genital opening; in female mongynaspine Mesostigmata this shield is usually called the epigynal (epigynial) shield.  
, and normal setation in the marginal-submarginal region.

Similar species

Key to Adult females of Species of Stratiolaelaps (from Walter & Campbell 2002)

1. Fixed digitfixed digit:
   the distal extension of the middle article of the chelicera; usually bearing teeth and a distal hook and opposed to the movable digit in chelate-dentate forms, but often regressed; in Mesostigmata the fixed digit may bear the pilus dentilis.
   of chelicerachelicera:
   a limb on the presumed first body segment in chelicerate arthropods, the primary mouthparts.  In mites the chelicerae are primitively chelate-dentate, but may be modified into almost unrecognizable forms.  In Acariformes, the chelicerae are usually 2-segmented, but in other mites and some basal acariforms they have three segments.  Rarely, in some Uropodoidea (Mesostigmata), a subdivision makes them appear 4-segmented.
   with 2 teeth anterior to pilus dentilispilus dentilis:
   (pl. pili dentilis) a seta-like or membranous sensory organ inserted ventrolaterally on the fixed digit of the chelicera of many Mesostigmata.
   , followed by serrateserrate:
   with closely set teeth that resemble the cutting edge of a saw.
   region; margin of gnathotectumgnathotectum:
   (= epistome, tectum) an often membranous dorsal projection of the anterior margin of the basis capitulum in Mesostigmata; often diagnostic at family-, genus- or species-levels; also often difficult to see without high magnification and good optics.
   denticulate, with longer median and lateral processes; posteriorposterior:
   the back part of the body or towards that region in comparison, e.g., 'posterior to'.
   margin of sternal shieldsternal shield:
   a shield in the anterior intercoxal region of parasitiform mites that bears one or more pairs of sternal setae.
   concave.............................. lamington group (2)
   - Fixed digitfixed digit:
   the distal extension of the middle article of the chelicera; usually bearing teeth and a distal hook and opposed to the movable digit in chelate-dentate forms, but often regressed; in Mesostigmata the fixed digit may bear the pilus dentilis.
   of chelicerachelicera:
   a limb on the presumed first body segment in chelicerate arthropods, the primary mouthparts.  In mites the chelicerae are primitively chelate-dentate, but may be modified into almost unrecognizable forms.  In Acariformes, the chelicerae are usually 2-segmented, but in other mites and some basal acariforms they have three segments.  Rarely, in some Uropodoidea (Mesostigmata), a subdivision makes them appear 4-segmented.
   with 2 teeth to either side of pilus dentilispilus dentilis:
   (pl. pili dentilis) a seta-like or membranous sensory organ inserted ventrolaterally on the fixed digit of the chelicera of many Mesostigmata.
   ; margin of gnathotectumgnathotectum:
   (= epistome, tectum) an often membranous dorsal projection of the anterior margin of the basis capitulum in Mesostigmata; often diagnostic at family-, genus- or species-levels; also often difficult to see without high magnification and good optics.
   denticulate, with single, smooth median process; posteriorposterior:
   the back part of the body or towards that region in comparison, e.g., 'posterior to'.
   margin of sternal shieldsternal shield:
   a shield in the anterior intercoxal region of parasitiform mites that bears one or more pairs of sternal setae.
   irregularly convex or produced medially.............................. miles group (3)

2. Dorsaldorsal:
   relating to the upper or back side; opposed to ventral.
   shield with 39 pairs of spatulatespatulate:
   (Latin spatula = spoon) spatula-shaped; variously interpreted, but usually referring to setae that are flattened and somewhat expanded distally.
   -mucronate setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   , paired accessory setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   px2, px3 present; postanal setapostanal seta:
   the unpaired median seta inserted posterior to the anal opening in the Mesostigmata; usually designated po or POS.
   and marginal setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   r6 and R1 spatulatespatulate:
   (Latin spatula = spoon) spatula-shaped; variously interpreted, but usually referring to setae that are flattened and somewhat expanded distally.
   ..............................S. lamington
   - Dorsaldorsal:
   relating to the upper or back side; opposed to ventral.
   shield with 37 pairs of spatulatespatulate:
   (Latin spatula = spoon) spatula-shaped; variously interpreted, but usually referring to setae that are flattened and somewhat expanded distally.
   -acuminate setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   , paired accessory px setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   absent; postanal setapostanal seta:
   the unpaired median seta inserted posterior to the anal opening in the Mesostigmata; usually designated po or POS.
   and marginal setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   r6 and R1 acicular.............................. S. womersleyi

3. Most dorsaldorsal:
   relating to the upper or back side; opposed to ventral.
   shield setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   relatively short, tips not exceeding next setaseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   in series; setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   J4 and J5 subequal, Z5 20–40% longer.............................. 4
   - Most dorsaldorsal:
   relating to the upper or back side; opposed to ventral.
   shield setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   relatively long (e.g., all podonotal setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   except z1 are 51–65 µm), tips approaching or passing insertion of next setaseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   in series; setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   J4 and Z5 much longer than J5 (50–60% and 60–100% longer, respectively).............................. S. marilyn

4. Setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   r6 similar toothers; dorsal setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   of femorafemur:
   (pl. femora) major leg segment between trochanter and genu; often subdivided into a basifemur and a telofemur.
   and genuagenu:
   (pl. genua) (= patella) the 4th leg segment, between the femur and tibia.
   of legs II and IV mostly spatulatespatulate:
   (Latin spatula = spoon) spatula-shaped; variously interpreted, but usually referring to setae that are flattened and somewhat expanded distally.
   ; dorsaldorsal:
   relating to the upper or back side; opposed to ventral.
   shield 585–690 µm long; fixed digitfixed digit:
   the distal extension of the middle article of the chelicera; usually bearing teeth and a distal hook and opposed to the movable digit in chelate-dentate forms, but often regressed; in Mesostigmata the fixed digit may bear the pilus dentilis.
   of male chelicerachelicera:
   a limb on the presumed first body segment in chelicerate arthropods, the primary mouthparts.  In mites the chelicerae are primitively chelate-dentate, but may be modified into almost unrecognizable forms.  In Acariformes, the chelicerae are usually 2-segmented, but in other mites and some basal acariforms they have three segments.  Rarely, in some Uropodoidea (Mesostigmata), a subdivision makes them appear 4-segmented.
   with one tooth posteriorposterior:
   the back part of the body or towards that region in comparison, e.g., 'posterior to'.
   to pilus dentilispilus dentilis:
   (pl. pili dentilis) a seta-like or membranous sensory organ inserted ventrolaterally on the fixed digit of the chelicera of many Mesostigmata.
   .............................. 5
   - Setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   r6 simplesimple:
   unadorned; simple setae are needle-like and without hairs or pectins.
   ; dorsal setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   of femorafemur:
   (pl. femora) major leg segment between trochanter and genu; often subdivided into a basifemur and a telofemur.
   and genuagenu:
   (pl. genua) (= patella) the 4th leg segment, between the femur and tibia.
   of legs II and IV simplesimple:
   unadorned; simple setae are needle-like and without hairs or pectins.
   ; dorsaldorsal:
   relating to the upper or back side; opposed to ventral.
   shield 540–590 µm long; fixed digitfixed digit:
   the distal extension of the middle article of the chelicera; usually bearing teeth and a distal hook and opposed to the movable digit in chelate-dentate forms, but often regressed; in Mesostigmata the fixed digit may bear the pilus dentilis.
   of male chelicerachelicera:
   a limb on the presumed first body segment in chelicerate arthropods, the primary mouthparts.  In mites the chelicerae are primitively chelate-dentate, but may be modified into almost unrecognizable forms.  In Acariformes, the chelicerae are usually 2-segmented, but in other mites and some basal acariforms they have three segments.  Rarely, in some Uropodoidea (Mesostigmata), a subdivision makes them appear 4-segmented.
   with 3–5 teeth posteriorposterior:
   the back part of the body or towards that region in comparison, e.g., 'posterior to'.
   to pilus dentilispilus dentilis:
   (pl. pili dentilis) a seta-like or membranous sensory organ inserted ventrolaterally on the fixed digit of the chelicera of many Mesostigmata.
   .............................. S. lorna

5. Dorsaldorsal:
   relating to the upper or back side; opposed to ventral.
   shield taperingtapering:
   drawn out or with margins converging.
   gradually after level of setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   S2; postanal setapostanal seta:
   the unpaired median seta inserted posterior to the anal opening in the Mesostigmata; usually designated po or POS.
   short, only about 60% length of paranal setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   ; palp apotelepalptarsal apotele:
   (= palp apotele, palptarsal claw) the most distal segment of the palp; absent in Acariformes, claw-like in Opilioacarida, and a subdistal, tined structure in the Mesostigmata.
   with 2 subequal tines.............................. S. miles Evans and Till 1966Evans and Till 1966:
   Evans GO, Till WM. 1966. Studies on the British Dermanyssidae (Acari: Mesostigmata). Part II. Classification. Bulletin of the British Museum (Natural History) Zoology 14: 107–370.
   - Dorsaldorsal:
   relating to the upper or back side; opposed to ventral.
   shield taperingtapering:
   drawn out or with margins converging.
   sharply after level of setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   S2; middle article of chelicerachelicera:
   a limb on the presumed first body segment in chelicerate arthropods, the primary mouthparts.  In mites the chelicerae are primitively chelate-dentate, but may be modified into almost unrecognizable forms.  In Acariformes, the chelicerae are usually 2-segmented, but in other mites and some basal acariforms they have three segments.  Rarely, in some Uropodoidea (Mesostigmata), a subdivision makes them appear 4-segmented.
   >260 µm long; postanal and paranal setaeseta:
   (pl. setae, from L. = bristle) cuticular process composed of a hollow shaft (sometimes filled with a refractive material) produced from a membranous socket (the alveolus); the hair-like, spine-like, branched or variously expanded structures on the surfaces of the legs and body.  Most setae function as mechanoreceptors, but others (e.g., solenidia) are chemoreceptors or have unknown or ambiguous functions.
   subequal in length; palp apotelepalptarsal apotele:
   (= palp apotele, palptarsal claw) the most distal segment of the palp; absent in Acariformes, claw-like in Opilioacarida, and a subdistal, tined structure in the Mesostigmata.
   with 2 subequal tines and a small basalbasal:
   towards the base of a structure; on a limb, towards the insertion on the body.
   tine.............................. S. scimitus (Womersley)

Ecology and distribution

Species of Stratiolaelaps are predatory and some are used in greenhouses against thrips and fungus gnats; S. womersleyi inhabits forest floor litter in rainforests in eastern Australia.

References

• Aswegen and Loots 1970Aswegen and Loots 1970:
  Aswegen PIM van, Loots GC. 1970. A taxonomic study of the genus Hypoaspis Canestrini sens. lat. (Acari: Laelapinae) in the Ethiopian region. Publicações Culturais da Companhia de Diamantes de Angola, Lisboa 82: 167–214.
• Berlese 1979 [1892]Berlese 1979 [1892]:
  Berlese A. 1979. Acari, Myriopoda et Scorpiones hucusque in Italia reperta, 63, 17 pp. + Plates 1-10. Junk, The Hague and Antiquariaat Junk, Amsterdam. (Original work published 1892)
• Berlese 1916Berlese 1916:
  Berlese A. 1916. Centuria seconda di Acari nuovi. Redia 12: 125–177.
• Chambers et al. 1993Chambers et al. 1993:
  Chambers RJ, Wright EM, Lind RJ. 1993. Biological control of glasshouse sciarid flies (Bradysia spp.) with the predatory mite, Hypoaspis miles, on cyclamen and poinsettia. Biocontrol Science and Technology 3: 285–293.
• Evans and Till 1966Evans and Till 1966:
  Evans GO, Till WM. 1966. Studies on the British Dermanyssidae (Acari: Mesostigmata). Part II. Classification. Bulletin of the British Museum (Natural History) Zoology 14: 107–370.
• Gilyarov and Bregatova 1977Gilyarov and Bregatova 1977:
  Gilyarov MS, Bregatova NG, eds. 1977. Handbook for the identification of soil-inhabiting mites, Mesostigmata. Zoological Institute of the Academy of Sciences, Petrograd.
• Karg 1993Karg 1993:
  Karg W. 1993. Acari (Acarina), Milben Parasitiformes (Anactinochaeta) Cohors Gamasina Leach, Raubmilben. Die Tierwelt Deutschlands 59: 1–523.
• Tenorio 1982Tenorio 1982:
  Tenorio JM. 1982. Hypoaspidinae (Acari: Gamasida: Laelapidae) of the Hawaiian Islands. Pacific Insects 24: 259–274.
• Walter and Campbell 2003Walter and Campbell 2003:
  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.
• Wright and Chambers 1994Wright and Chambers 1994:
  Wright EM, Chambers RJ. 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 1956Womersley 1956:
  Womersley H. 1956. On some new Acarina-Mesostigmata from Australia, New Zealand and New Guinea. Journal of the Linnean Society of London, Zoology 42: 505–599.
• Zumpt and Patterson 1951Zumpt and Patterson 1951:
  Zumpt F, Patterson PM. 1951. Further notes on laelaptid mites parasitic on vertebrates. A preliminary study to the Ethiopian fauna. Journal of the Entomological Society of Southern Africa 14: 63–93.