Soil Acarology (Mites)Day – 3

Felicity Crotty

>30taxa

5000

1500

25 0

00

6500

730

160 60

0

60 0

00

1600 88

00

5000

2500 10

000

9260

9539

208

300

70

3627

162 77

3

56

52 %

75 %

47 %

50 %

54 %

99 %

NE

NE

NE

NE

NE

NE

NE

1

10

100

1000

10 000

100 000

1 000 000

10 000 000

Nemat

oda

Prot

ozoa

Acar

iCo

llem

bola

Dipl

ura

Sym

phyla

Ench

ytra

eida

eDi

pter

aIs

opte

raFo

rmico

idea

Isop

oda

Chilo

poda

Dipl

opod

a

Oth

er A

rach

nida

Aran

eae

Cole

opte

raM

ollu

sca

Olig

ocha

eta

Caec

ilian

Sqam

ata

Mam

mal

ia

Estimated, undescribed species

Known species

NE

83 %

41 %

75 %

NE

97 %

99 %

72 %

Species number

Body size Source: Decaëns et al. (2006)

But mostly unknown...

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

Acari

Parasitiformes Acariformes

Sub-Class

Super-Order

Order Opilloacarida Holothrida Mesostigmata Ixodida Sarcoptiformes Trombidiformes

Sub-Order Sejida

Trigynaspida Monogynaspida Endeostigmata

Oribatida

Sphaerolichida

Prostigmata

Super-Cohort

Palaeosomata

Parhyposomata

BrachypylinaEnarthronota

Mixonomata Desmonomata

Cohort

Cercomegistina

Antennophorina

Microgynina

Heatherellina

HeterozerconinaUropodina

Gamasina

Astigmata

Labidostommatides

Eupodides

AnystidesEleutherengonides

Anystina

Parasitengonina

Raphignathina

Heterostigmata

Sub-Cohort /Infra-Order

ArctacariaeParasitiae

Epicriiae

Dermanyssiae

Pycnonticae

Poronoticae

Euptyctima

Dichosomata

ParasitiformesMesostigmata

• Cosmopolitan• Most free living

predators• Suborders:

- Sejida-

Trigynaspida-

Monogynaspida

Holothyrida

• In leaf litter, mosses and under stones in moist forests

• rare• Families:

- Holothyridae

- Allothyridae-

Neothyridae

Ixodidae

• Obligate blood sucking parasites

• Common• Families:

- Ixodidae (Hard)

- Argasidae (Soft)

- Nuttalliellidae

Opilioacaridae

• Look superficially like harvestmen

• Found in caves, also under rocks and litter

• Moderately rare• 6 genera; 20

species

ParasitiformesMesostigmata

• Cosmopolitan• Most free living

predators• Suborders:

- Sejida-

Trigynaspida-

Monogynaspida

Holothyrida

• In leaf litter, mosses and under stones in moist forests

• rare• Families:

- Holothyridae

- Allothyridae-

Neothyridae

Ixodidae

• Obligate blood sucking parasites

• Common• Families:

- Ixodidae (Hard)

- Argasidae (Soft)

- Nuttalliellidae

Opilioacaridae

• 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

van Eekeren, Murray & Smeding (2007)

Cyclic interactions

More food for soil biotaImproved habitat for soil biota

Improved soil structureImproved nutrient cyclingImproved water regulation

Greater plant yield (more litter produced)More efficient moisture and nutrient uptakeImproved rooting

Blue = BacterialGreen = FungalRed = Root

Adapted from De Ruiter et al. (1993) J. Appl. Ecol. 30, 95-106

Roots

Phytophagous nematodes

Rhizophagousaphids

Detritus

Fungi

Collembola

Cryptostig.mites

Non-cryptostig.mites

Fungivorousnematodes

Earthworms

Enchytraeids

Bacteriophagousnematodes

Flagellates

Bacteriophagousmites

Amoebae

Predaceousnematodes

Nematode feedingmites

Predaceouscollembola

Predaceousmites

Winter Wheat fields:Netherlands

Bacteria

Trophic patterns in Acari

(Ticks)

(Similar to

harvestm

en)(ra

re)

(macro

pyline)

(brachypyline)

(mainly predators)

Feeding strategies

Saprophagy (phyllophagy) – using parenchymous tissue of dead leaves

Saprophagy (xylophagy) – using woody structural tissue / dead plant parts e.g. Mixonomata species

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

DIRECT: Assimilation of nutrients from plant materials; Concentration of nutrients (and heavy metals)INDIRECT: Shredding increases nutrient leaching

Nutrient Cycling

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 / BacteriophagyEnergy Flow

DIRECT: Assimilation of energy from microfloraINDIRECT: Stimulation / suppression of microfloral activities. Dispersal of hyphae/spores. Selective grazing.

DIRECT: Assimilation of nutrients from plant materials; Concentration of nutrients (and heavy metals)INDIRECT: Stimulation or suppression of microfloral activities

Nutrient Cycling

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 MesostigmataSome Oribatida

Fluid feeding fungivore Pierce and suck fluids of fungi, protists

Prostigmata

Engulfing fungivores Ingest bits of fungi, hyphae, algae, spores

OribatidaAstigmata

Root fluid feeders (Herbivores)

Pierce roots and suck fluids Some Prostigmata

Detritivores Ingest dead plant material OribatidaAstigmata

Coprophagous Ingest faecal / exoskeleton material

OribatidaAstigmata

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/mites/invasive_mite/

Invasive_Mite_Identification/key/0_Glossary/

Mite_Glossary.htm

JARGONBody 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)

Mouth parts/head

Legs I & II

Legs III & IV

Abdomen region

Gnathosoma (sometimes referred to as capitulum)

Propodosoma (dorsal surface = prodorsum)

Metapodosoma

Opisthosoma(Opisthonotal if dorsal)

Podosoma

Idiosoma (body)Gaster if ventral or notum if dorsal

Prosoma (= cephalothorax)Aspidosoma is anterior dorsal region

Proterosoma(Anterior of sejugal furrow)

Hysterosoma(Rear of sejugal furrow)Dorsally called notogaster

Mite arbitrary body divisions (JARGON)

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