Soil Acarology (Mites)
Day – 3
Felicity Crotty
>30
taxa
But mostly unknown...
Estimated, undescribed species
Species number
Known species
NE
10 000
1000
NE
NE
75 %
56
162
773
100
3627
70
208 300
9539
9260
10 000
100 000
52 %
NE
NE
83 %
NE
1 000 000
NE
2500
41 %
NE
5000
1600
60 000
600
8800
47 %
50 %
NE
160
730
6500
25 000
54 %
72 %
97 %
99 %
1500
5000
99 %
75 %
10 000 000
10
1
Body size
Source: Decaëns et al. (2006)
What is a Mite?!?
Tiny but diverse arachnids related to
spiders, are some of the most abundant
and diverse groups of invertebrate fauna.
Found in all environments worldwide,
from the deserts to the polar regions and
everything in between .
The are predators, fungivores,
detritivores and even herbivores.
Thus occupying many different niches
and speciating to adapt to the ecosystem
they are inhabiting
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
Parasitiformes
Mesostigmata
Holothyrida
• In leaf litter,
• Cosmopolitan
mosses and
• Most free living
under stones in
predators
moist forests
• Suborders:
• rare
- Sejida
• Families:
- Trigynaspida
- Holothyridae
- Monogynaspida
- Allothyridae
- Neothyridae
Ixodidae
Opilioacaridae
• Obligate blood
sucking parasites
• Common
• Families:
- Ixodidae (Hard)
- Argasidae (Soft)
- Nuttalliellidae
• Look superficially
like harvestmen
• Found in caves,
also under rocks
and litter
• Moderately rare
• 6 genera; 20
species
Parasitiformes
Mesostigmata
Holothyrida
• In leaf litter,
• Cosmopolitan
mosses and
• Most free living
under stones in
predators
moist forests
• Suborders:
• rare
- Sejida
• Families:
- Trigynaspida
- Holothyridae
- Monogynaspida
- Allothyridae
- Neothyridae
Ixodidae
Opilioacaridae
• Obligate blood
sucking parasites
• Common
• Families:
- Ixodidae (Hard)
- Argasidae (Soft)
- Nuttalliellidae
• Look superficially
like harvestmen
• Found in caves,
also under rocks
and litter
• Moderately rare
• 6 genera; 20
species
Acariformes
Sarcoptiformes (Oribatida)
• Mostly Oribatids
(Endeostigmata also a
suborder in this group and
Astigmata a cohort within
Oribatida)
• Oribatids four supercohorts
considered “lower”
oribatids – MACROPYLINE
one supercohort considered
“higher” – BRACHYPYLINE
• Extremely common
Trombidiformes (Prostigmata)
• Mostly Prostigmata
(Sphaerolichida also a
suborder in this group)
• Prostigmata with five
supercohorts (variable
family number within)
• Extremely common
• Mixture of predators and
herbivores/fungivores
• Many have a phoretic
immature stage “chiggers”
Mite Ecology
Day – 3
Felicity Crotty
Almost nothing known of the
biology and basic needs of most
native species
Cyclic interactions
Greater plant yield
(more litter produced)
More efficient moisture
and nutrient uptake
Improved rooting
More food for soil biota
Improved habitat for soil
biota
Improved soil structure
Improved nutrient cycling
Improved water regulation
van Eekeren, Murray & Smeding (2007)
Rhizophagous
aphids
Phytophagous
nematodes
Roots
Collembola
Cryptostig.
mites
Non-cryptostig.
mites
Fungi
Fungivorous
nematodes
Earthworms
Detritus
Predaceous
mites
Predaceous
collembola
Nematode feeding
mites
Predaceous
nematodes
Enchytraeids
Bacteria
Winter Wheat fields:
Netherlands
Adapted from De
Ruiter et al. (1993) J.
Appl. Ecol. 30, 95-106
Bacteriophagous
nematodes
Flagellates
Bacteriophagous
mites
Amoebae
Blue = Bacterial
Green = Fungal
Red = Root
Trophic patterns in Acari
Feeding strategies
Saprophagy
(xylophagy)
– using
woody
structural
tissue /
dead plant
parts e.g.
Mixonomata
species
Saprophagy
(phyllophagy)
– using
parenchymous
tissue of dead
leaves
R. Norton
R. Norton
Saprophagy (Phyllo / Xylo)
Energy Flow
DIRECT: Assimilation of energy from plant materials
(BUT low quality food – high C:N; produce large
faecal pellets – little of C is used)
INDIRECT: Production of faecal pellets with greater
surface area – “material going through digestive
tract of total mite population in 1 year, apx equal to
50% of annual litter fall!” Berthet 1964
Nutrient Cycling
DIRECT: Assimilation of nutrients from plant
materials; Concentration of nutrients (and heavy
metals)
INDIRECT: Shredding increases nutrient leaching
Feeding strategies
Mycophagy –
feeding on
fungal
hyphae or
spores
(usually
growing on
decaying
plant
material)
Other strategies include:
- Necrophagy
- Coprophagy
- Bacteriophagy
- Nematophagy
- Protistivory
- Herbivory (root /
living tissue)
- Algivory
- Omnivory
- Predation
Mycophagy / Bacteriophagy
Energy Flow
DIRECT: Assimilation of energy from microflora
INDIRECT: Stimulation / suppression of
microfloral activities. Dispersal of
hyphae/spores. Selective grazing.
Nutrient Cycling
DIRECT: Assimilation of nutrients from plant
materials; Concentration of nutrients (and heavy
metals)
INDIRECT: Stimulation or suppression of
microfloral activities
Functional groups of mites
(cf. Moore et al. 1988)
Functional Group
Description
Taxa
General predators
Attack anything smaller
Mesostigmata
Arthropod predators
Attack only Arthropods
Many Prostigmata
Nematode Predators
Only nematodes
Mesostigmata
Some Oribatida
Fluid feeding fungivore
Pierce and suck fluids of
fungi, protists
Prostigmata
Engulfing fungivores
Ingest bits of fungi,
hyphae, algae, spores
Oribatida
Astigmata
Root fluid feeders
(Herbivores)
Pierce roots and suck fluids Some Prostigmata
Detritivores
Ingest dead plant material
Oribatida
Astigmata
Coprophagous
Ingest faecal / exoskeleton
material
Oribatida
Astigmata
Aboveground communities are affected by both direct and indirect
consequences of soil food web.
- Indirect (R) detritus food web stimulate nutrient turnover
improving plant performance.
- Direct (L) soil biota feed on roots and form antagonistic /
mutualistic relationships
Wardle et al., Science 2004
Microhabitats
•
•
•
•
•
•
•
•
Burrowers
Soil dwellers
Lichen associates
Saxicoles (rock dwellers)
Arboreal – “island soil colonies”
Marine littoral
Fresh water
Insect Associates
Biology
• The majority of the Mesostigmata and
Prostigmata are r-strategists with fast
reproductive cycles, short lifespans and quick
recovery times to perturbations
• Majority of the Oribatids are k-strategists with
slow reproductive cycles, long lifespans and
are slow to recover to perturbations – may
therefore be a good indication group
Mite Glossary
http://itp.lucidcentral.org/id/mi
tes/invasive_mite/Invasive_Mite
_Identification/key/0_Glossary/
Mite_Glossary.htm
JARGON
Body Regions
•
•
•
•
•
•
-soma = body
Pro- = front
Opistho- = back
Podo- = foot
Gnatho- = jaw/mouth/head
Idio- = distinct / unique
Different order = different words
OR even different key
• Prosoma = front body
- carapace?
- prodorsal
- pronotal ≠ notum = back
- podonotal
• Opisthosoma = back body
- Opisthonotal
- Opisthogaster (gaster =
stomach)
Mite arbitrary body divisions (JARGON)
Mouth
parts/head
Legs I & II
Legs III & IV
Abdomen
region
Gnathosoma
(sometimes referred to
as capitulum)
Propodosoma
(dorsal surface =
prodorsum)
Podosoma
Proterosoma
Prosoma
(= cephalothorax)
Aspidosoma is
anterior dorsal
region
Metapodosoma
Idiosoma (body)
Opisthosoma
(Opisthonotal if dorsal)
Gaster if ventral or
notum if dorsal
(Anterior of
sejugal furrow)
Hysterosoma
(Rear of sejugal
furrow)
Dorsally called
notogaster
JARGON… It’s getting “trichy”
- CHAETOTAXY (setal position / hairs)
• Holotrichy – complete complement of setae
thought to be present in ancestral group
- Unideficient – lost one setae (f1)
• Neotrichy – setae not in ancestral condition
(new hairs)
• Hypertrichy – extra setae