Soil Acarology (Mites) Day – 3 Felicity Crotty Mite Phylogeny Day – 3 Felicity Crotty >30 taxa 5000 99 % Known species Known 1500 99 % species undescribed Estimated, 25 000 97 % 6500 72 % 730 54 % Body size Body 160 NE 600 50 % 60 000 75 % 1600 47 % 8800 41 % 5000 NE 2500 NE But mostlyunknown... 10 000 83 % 9260 NE 9539 NE 208 300 NE 70 75 % Source: Decaëns et al.et (2006) DecaënsSource: 3627 52 % 162 NE 773 NE Species number 56 NE 10 1 000 000 0001 1 1000 10 000 000 100 000 100 10 00010 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 Parasitiformes – 4 orders Mesostigmata Holothyrida Ixodidae Opilioacaridae • Cosmopolitan • In leaf litter, • Obligate blood • Look superficially • Most free living mosses and sucking parasites like harvestmen predators under stones in • Common • Found in caves, moist forests • Suborders: • Families: also under rocks • rare and litter - Sejida - Ixodidae (Hard) • Families: • Moderately rare - Trigynaspida - Argasidae (Soft) - Holothyridae • 6 genera; 20 - Monogynaspida - Nuttalliellidae - Allothyridae species - Neothyridae Parasitiformes Mesostigmata Holothyrida Ixodidae Opilioacaridae • Cosmopolitan • In leaf litter, • Obligate blood • Look superficially • Most free living mosses and sucking parasites like harvestmen predators under stones in • Common • Found in caves, moist forests • Suborders: • Families: also under rocks • rare and litter - Sejida - Ixodidae (Hard) • Families: • Moderately rare - Trigynaspida - Argasidae (Soft) - Holothyridae • 6 genera; 20 - Monogynaspida - Nuttalliellidae - Allothyridae species - Neothyridae Acariformes 2 orders Sarcoptiformes (Oribatida) Trombidiformes (Prostigmata) • Mostly Oribatids • Mostly Prostigmata (Endeostigmata also a (Sphaerolichida also a suborder in this group and suborder in this group) Astigmata a cohort within • Prostigmata with five Oribatida) supercohorts (variable • Oribatids four supercohorts family number within) considered “lower” • Extremely common oribatids – MACROPYLINE • Mixture of predators and one supercohort considered herbivores/fungivores “higher” – BRACHYPYLINE • Many have a phoretic • Extremely common immature stage “chiggers” UK MESOSTIGMATA = 501 SPECIES (more now?) UK ORIBATIDS = 311 SPECIES ASTIGMATINA = 278 SPECIES UK PROSTIGMATA = 910 SPECIES Mite Ecology Day – 3 Felicity Crotty Active layer • Most of the action occurs in the first 2cm of soil • All invertebrates living in top 10 cm of soil • (Some worms and mammals further down than this) Not just earthworms affecting soil structure! Abundance! Grassland soils: We have apx 23,000 “Mesofauna” springtails and 41,000 (springtails & mites) mites per m2. = found between 64,000 per m2 60,000 – 100,000 m2. Almost nothing known of the biology and basic needs of most native species Cyclic interactions van Eekeren, Murray & Smeding (2007) Greater plant yield More food for soil biota (more litter produced) Improved habitat for soil More efficient moisture biota and nutrient uptake Improved rooting Improved soil structure Improved nutrient cycling Improved water regulation Trophic patterns in Acari Feeding strategies Saprophagy Saprophagy (phyllophagy) (xylophagy) – using – using parenchymous woody tissue of dead structural leaves 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 Nutrient Cycling DIRECT: Assimilation of nutrients from plant materials; Concentration of nutrients (and heavy metals) INDIRECT: Shredding increases nutrient leaching Feeding strategies Mycophagy – Other strategies include: feeding on - Necrophagy fungal - Coprophagy hyphae or - Bacteriophagy spores - Nematophagy (usually - Protistivory growing on - Herbivory (root / decaying living tissue) plant - Algivory material) - 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 Prostigmata fungi, protists Engulfing fungivores Ingest bits of fungi, Oribatida hyphae, algae, spores Astigmata Root fluid feeders Pierce roots and suck fluids Some Prostigmata (Herbivores) Detritivores Ingest dead plant material Oribatida Astigmata Coprophagous Ingest faecal / exoskeleton Oribatida material Astigmata 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 Electronic Glossary http://itp.lucidcentral.org/id/mi tes/invasive_mite/Invasive_Mi te_Identification/key/0_Gloss ary/Mite_Glossary.htm OR back of mite key JARGON Different order = different words Body Regions OR even different key • -soma = body • Prosoma = front body • Pro- = front - carapace? • Opistho- = back - prodorsal • Podo- = foot - pronotal ≠ notum = back • Gnatho- = jaw/mouth/head - podonotal • Idio- = distinct / unique • Opisthosoma = back body - Opisthonotal - Opisthogaster (gaster = stomach) Mite arbitrary body divisions (JARGON) Mouth Gnathosoma Proterosoma (sometimes referred to parts/head Prosoma (Anterior of as capitulum) sejugal furrow) (= cephalothorax) Propodosoma Aspidosoma is Legs I & II (dorsal surface = Podosoma anterior dorsal prodorsum) region Hysterosoma Metapodosoma (Rear of sejugal Legs III & IV furrow) Idiosoma (body) Dorsally called Abdomen Opisthosoma Gaster if ventral or notogaster region (Opisthonotal if dorsal) notum if dorsal JARGON… It’s getting “trichy” - CHAETOTAXY (setal position / hairs) • Holotrichy – full set of setae thought to be present in ancestral group - Unideficient – lost one setae (f1) • Neotrichy – setae not in ancestral formation (new hairs) • Hypertrichy – extra setae Acknowledgments Soil Mite Experts Cal Welbourne Valerie Behan-Pelletier Roy Norton David Walter.