Mite preparations for
identifications
Day – 3
Felicity Crotty
Collection
• Most common method for
mite collection is the use of
Tullgren funnels.
• Although others possible –
floatation / pooters.
• Collection / storage in 70%
alcohol best method (unless
want to further experiment)
• Saturated salt solution also
used
Soil Mesofauna = Springtails and Mites
Mites (Acari)
•
•
•
•
Three main orders
Mesostigmata
Oribatids
Prostigmata
• 45,000 described spp
• Approx 64 spp in 1 grassland
Stable Community Composition: Mites
Diversity mites in grassland
(+/- 0.05 s.e.)
Diversity of mites in
willow woodland
(+/- 0.05 s.e.)
9%
11%
16%
31%
23%
14%
61%
35%
ASTIGMATA
MESOSTIGMATA
ASTIGMATA
MESOSTIGMATA
ORIBATID
PROSTIGMATA
ORIBATID
PROSTIGMATA
Preservation
• Dissecting microscope to
sort through fauna
• Compound microscope to
observe external structures
for key
• Highly sclerotised mites need
to be “cleared” and disected
before mounting on slides
• This is to make “permanent”
slides
Mite
stored in
alcohol
Mite soaked
overnight in 90%
lactic acid (on
warmer)
Mite placed on slide
in pva, coverslip
edges sealed with dpx
“Quick”
Preservation
• Mites were left in eppendorfs
on a plate heater (lowest
setting) overnight
• PVA = polyvinyl alcohol (I used
to get mine from Sigma) I used
1 drop ~ 3 µl
• DPX = DPX Mountant (again
from Sigma)
• Nail polish could also be used
instead of DPX, but this does
not last as long
Mite
stored in
alcohol
Mite soaked
overnight in 90%
lactic acid (on
warmer)
Mite placed on slide
in PVA, coverslip
edges sealed with
DPX
Identification
• What level?
- Order (Collembola or Mite)
- Lineage (Mesostigmata/Oribatida)
- Supercohort
(Macropyline/Brachypyline)
- Cohort
(Palaeosomata/Mixonomata)
- Superfamily
(Phthiracaroidea/Lohmannioidea)
Sub-Class
Acari
Super-Order
Order
Parasitiformes
Holothrida
Opilloacarida
Trigynaspida
Acariformes
Mesostigmata
Sub-Order
Sphaerolichida
Endeostigmata
Monogynaspida
Palaeosomata
Eupodides
Parhyposomata
Labidostommatides
Enarthronota
Cohort
Microgynina
Eleutherengonides
Brachypylina
Astigmata
Uropodina
Heterostigmata
Antennophorina
Sub-Cohort /
Infra-Order
Arctacariae
Parasitengonina
Gamasina
Euptyctima
Epicriiae
Parasitiae
Raphignathina
Anystina
Heterozerconina
Heatherellina
Anystides
Desmonomata
Mixonomata
Cercomegistina
Prostigmata
Oribatida
Sejida
Super-Cohort
Trombidiformes
Sarcoptiformes
Ixodida
Dermanyssiae
Dichosomata
Pycnonticae
Poronoticae
Methods of identification
•
•
•
•
Computer based key “Lucid”
Available online
“Major mite taxa” home page
http://itp.lucidcentral.org/id/mites/invasive_mite/I
nvasive_Mite_Identification/key/Major_Mite_taxa/
Media/Html/Home_Major_Mite_Taxa.html
• Unfortunately doesn’t cover that much –
Order: Opilioacarida, Holothyrida, and Ixodida;
Suborder: Mesostigmata;
Supercohort: Oribatida and Prostigmata.
SIMILAR TO ISPOT KEYS – but computer needs Java
Different Lucid Key
Greater scope
- COHORT
Mesostigmata,
Oribatid and
Prostigmata.
http://keys.lucid
central.org/keyserver/player.jsp
?keyId=42
Dichotomous Keys
• Used Tiling Key &
Hopkins
• Paired statements of
either words or images
• Have to follow specific
order
• If character unknown /
can’t see it easy to
make a mistake and
misidentify
Dichotomous keys
• Greater depth
Orders…
Lineages…
Families…
Genus…
Species
Sub-Class
Acari
Super-Order
Order
Parasitiformes
Holothrida
Opilloacarida
Trigynaspida
Acariformes
Mesostigmata
Sub-Order
Sphaerolichida
Endeostigmata
Monogynaspida
Palaeosomata
Eupodides
Parhyposomata
Labidostommatides
Enarthronota
Cohort
Microgynina
Eleutherengonides
Brachypylina
Astigmata
Uropodina
Heterostigmata
Antennophorina
Sub-Cohort /
Infra-Order
Arctacariae
Parasitengonina
Gamasina
Euptyctima
Epicriiae
Parasitiae
Raphignathina
Anystina
Heterozerconina
Heatherellina
Anystides
Desmonomata
Mixonomata
Cercomegistina
Prostigmata
Oribatida
Sejida
Super-Cohort
Trombidiformes
Sarcoptiformes
Ixodida
Dermanyssiae
Dichosomata
Pycnonticae
Poronoticae
Sub-Class
Acari
Super-Order
Order
Parasitiformes
Holothrida
Opilloacarida
Trigynaspida
Acariformes
Mesostigmata
Sub-Order
Sphaerolichida
Endeostigmata
Monogynaspida
Palaeosomata
Eupodides
Parhyposomata
Labidostommatides
Enarthronota
Cohort
Microgynina
Eleutherengonides
Brachypylina
Astigmata
Uropodina
Heterostigmata
Antennophorina
Sub-Cohort /
Infra-Order
Arctacariae
Parasitengonina
Gamasina
Euptyctima
Epicriiae
Parasitiae
Raphignathina
Anystina
Heterozerconina
Heatherellina
Anystides
Desmonomata
Mixonomata
Cercomegistina
Prostigmata
Oribatida
Sejida
Super-Cohort
Trombidiformes
Sarcoptiformes
Ixodida
Dermanyssiae
Dichosomata
Pycnonticae
Poronoticae
Soil Mite or Tick?!
Parasitiformes
Mesostigmata
Ixodida
Soil Mite or Tick?!
Parasitiformes
Mesostigmata
- Smaller than ~ 5mm
- Peritremes and stigmatal opening
present (at level of coxae II-IV)
- Four pairs of setae on subcapitulum
- Apotele with 2 or 3 tines
- Tritosternum present
- Female covered by 1-4 epigynal
shields
Ixodida
- Greater than ~5mm
- Peritremes and stigmatal opening
absent
- Subcapitulum with denticulate
hypostome
- Palps usually 4 or fewer segments,
without apotele
- Tritosternum absent
Soil Mite or Tick?!
Parasitiformes
Mesostigmata
Ixodida
Acari Key to main groups
• Stigmata usually without noticeable peritremes, and
not situated at each side of the body near coxae I-IV.
FEMALES: Genital shield jointed to open at one lateral
edge of shield …………………………………………………..(next)
• Stigmata, one on each side of the body, situated in the
region of coxae I-IV and usually provided with an
elongate peritreme; chelicerae chelate-dentate mainly.
FEMALES: Genital shield jointed to open at base. –
Mesostigmata (or Parasitiformes) (Figure)
Chelicerae
Chelate-dentate
6 free segments: Tarsus, tibia, genu,
femur, trochanter, coxae
Stigmata and peritreme
Probably
male as
epigynal
shield not
distinct, or
hinged
Acari Key to main groups
• Gnathosoma with conspicuous rutella; chelicerae
chelate, rarely modified; pedipalps simple.
Tracheal system opening through stigmata or
‘pores’ on various parts of the body or absent;
Body weakly OR strongly sclerotized. – Oribatida
• Tracheal system opening through a pair of
stigmata situated on or near the base of the
gnathosoma; chelicerae and pedipalps usually
strongly modified. Body usually poorly
sclerotized. – Prostigmata
Figure 1 Oribatida
Rutella
Chelicerae Chelate
Tracheal system
Oxotaxic pores
Genital and anal
shields
But this is also an Oribatid…
AND this is an Oribatid too!
Prostigmata
Chelicerae and
pedipalps
modified
Stigmata at base
of gnathosoma
Body weakly
sclerotised
5 free segments:
Tarsus, tibia,
genu, femur,
trochanter.
CHARACTER
PARASITIFORMES
(MESOSTIGMATA)
SARCOPTIFORMES
(ORIBATIDS & ASTIGS)
TROMBIDIFORMES
(PROSTIGMATA)
Chelicerae
Chelate-dentate (except parasites)
Usually chelate-dentate
Often modified (spikes, stylets)
Hypostomal groove
Present
Absent
Absent
Tritosternum
Usually present
Absent
Absent
Gnathosomal tectum
Present
Absent
Absent
Palps
Usually well developed, limb-like
5-segmented in Oribatida;
2-segmented in Astigmata
Often reduced or modified
Palp apotele
Present
Absent
Absent
Palp thumbclaw
Present
Absent
Sometimes present
Dorso-sejugal suture
Absent
Present
Often indistinct
Eyes
Absent (except Allothyridae)
Absent (rare exceptions)
Sometimes present
Trichobothria
Absent
Present (except Nothroidea)
Often present
Dorsal & ventral plates
Usually 1 or 2 dorsal plates and
various ventral plates
Usually well developed dorsal and
ventral plates
Often absent or small (numerous
exceptions)
Colour
Usually brown to red-brown
Usually brownish to black
Often white, yellow, green, red
Genital & anal openings
Genital plate undivided, anal plate
divided
With divided plates
Usually without plates
Genital papillae
Absent
Present
Often present
Lateral peritreme
Usually present
Absent
Absent
Lateral opisthosomal gland
Absent
Usually present
Absent
Coxae
free
Fused to ventral body
Fused to body
CHARACTER
PARASITIFORMES
(MESOSTIGMATA)
SARCOPTIFORMES
(ORIBATIDS & ASTIGS)
TROMBIDIFORMES
(PROSTIGMATA)
Chelicerae
Chelate-dentate
Usually chelate-dentate
Often modified (spikes, stylets)
Hypostomal groove
Present
Absent
Absent
Tritosternum
Usually present
Absent
Absent
Gnathosomal tectum
Present
Absent
Absent
Palps
Usually well developed,
limb-like
5-segmented in Oribatida;
2-segmented in Astigmata
Often reduced or modified
Palp apotele
Present
Absent
Absent
Palp thumbclaw
Present
Absent
Sometimes present
Dorso-sejugal suture
Absent
Present
Often indistinct
Eyes
Absent (except Allothyridae)
Absent (rare exceptions)
Sometimes present
Trichobothria
Absent
Present (except Nothroidea)
Often present
Dorsal & ventral plates
Usually 1 or 2 dorsal plates and
various ventral plates
Usually well developed dorsal
and ventral plates
Often absent or small (numerous
exceptions)
Colour
Usually brown to red-brown
Usually brownish to black
Often white, yellow, green, red
Genital & anal openings
Genital plate undivided,
anal plate divided
With divided plates
Usually without plates
Genital papillae
Absent
Present
Often present
Lateral peritreme
Usually present
Absent
Absent
Lateral opisthosomal gland
Absent
Usually present
Absent
Coxae
Free
Fused to ventral body
Fused to body
CHARACTER
PARASITIFORMES
(MESOSTIGMATA)
SARCOPTIFORMES
(ORIBATIDS & ASTIGS)
TROMBIDIFORMES
(PROSTIGMATA)
Chelicerae
Chelate-dentate
Usually chelate-dentate
Often modified (spikes, stylets)
Hypostomal groove
Present
Absent
Absent
Tritosternum
Usually present
Absent
Absent
Gnathosomal tectum
Present
Absent
Absent
Palps
Usually well developed, limb-like
5-segmented in Oribatida;
2-segmented in Astigmata
Often reduced or modified
Palp apotele
Present
Absent
Absent
Palp thumbclaw
Present
Absent
Sometimes present
Dorso-sejugal suture
Absent
Present
Often indistinct
Eyes
Absent (except Allothyridae)
Absent (rare exceptions)
Sometimes present
Trichobothria
Absent
Present
Often present
Dorsal & ventral plates
Usually 1 or 2 dorsal plates and
various ventral plates
Usually well developed
dorsal and ventral plates
Often absent or small (numerous
exceptions)
Colour
Usually brown to red-brown
Usually brownish to black
Often white, yellow, green, red
Genital & anal
openings
Genital plate undivided, anal plate
divided
With divided plates
Usually without plates
Genital papillae
Absent
Present
Often present
Lateral peritreme
Usually present
Absent
Absent
Lateral opisthosomal gland
Absent
Usually present
Absent
Coxae
free
Fused to ventral body
Fused to body
CHARACTER
PARASITIFORMES
(MESOSTIGMATA)
SARCOPTIFORMES
(ORIBATIDS & ASTIGS)
TROMBIDIFORMES
(PROSTIGMATA)
Chelicerae
Chelate-dentate
Usually chelate-dentate
Often modified
Hypostomal groove
Present
Absent
Absent
Tritosternum
Usually present
Absent
Absent
Gnathosomal tectum
Present
Absent
Absent
Palps
Usually well developed, limb-like
5-segmented in Oribatida;
2-segmented in Astigmata
Often reduced or modified
Palp apotele
Present
Absent
Absent
Palp thumbclaw
Present
Absent
Sometimes present
Dorso-sejugal suture
Absent
Present
Often indistinct
Eyes
Absent (except Allothyridae)
Absent (rare exceptions)
Sometimes present
1 to 2 pairs)
Trichobothria
Absent
Present (except Nothroidea)
Often present
Dorsal & ventral plates
Usually 1 or 2 dorsal plates and
various ventral plates
Usually well developed dorsal and
ventral plates
Often absent or small (numerous
exceptions)
Colour
Usually brown to red-brown
Usually brownish to black
Often white, yellow, green, red
Genital & anal openings
Genital plate undivided, anal plate
divided
With divided plates
Usually without plates
Genital papillae
Absent
Present
Often present
Lateral peritreme
Usually present
Absent
Absent
Opisthosomal gland
Absent
Usually present
Absent
Coxae
free
Fused to ventral body
Fused to body
Best Keys?
• Mesostigmatic mites of Britain and Ireland –
Evans and Till (1979) Trans. Zool. Soc. Lond. 35,
139-270
• Oribatida – Norton and Behan-Pelletier (2009) In
A manual of acarology. Krantz and Walter.
• OR: Acarina: Oribatida – Norton (1990) In Soil
Biology. Dindal
• Acarina: Prostigmata – Kethley (1990) In Soil
Biology. Dindal
• Acarina: Astigmata – Philips (1990) In Soil Biology.
Dindal
Soil Acarology 3 week course
Summer 2014
http://www.biosci.ohiostate.edu/~acarolog/summerProgram/index.html
Acknowledgments
Soil Mite Experts
Cal Welbourne
Valerie Behan-Pelletier
Roy Norton
David Walter