File:Soilchart.png

2018-05-09T05:19:10Z

Elsbethd:

Silt

2018-05-09T05:15:31Z

Elsbethd: /* Identification */

==Definition==

[[File:Silty.jpg|thumb|right|Silt [6]]]

Silt is a granular sediment that can be transported and deposited by water, ice, and wind. Silt particles are larger than clay, but smaller than sand. To be classified as silt, a particle must be between .002 to .05 mm [1]. Similarly to [[clay]], sand, and gravel, silt is found in [[soil]]. Silt can also occur as sediment mixed in suspension with water. Because of silt’s spherical shape, it retains a large amount of water. Silty soil is known to be more fertile than other soils, and many species of [[organisms]] thrive in it.

==Formation==

Silt-producing mechanisms include frost shattering (Freeze-Thaw Weathering), comminution during transport, eolian abrasion, salt weathering, and glacial grinding. Windblown silt blankets the land in many parts of the world [2]. Large deposits of silt, such as this, are known as loess. Loess landscapes are usually a sign of past glacial activity, including areas such as the Great Plains. Silt can accumulate quickly in areas that lack vegetation, which can disrupt ecosystems. Silt also settles in still water, resulting in build ups like deltas. The main mineral origin of silt is quartz and feldspar [3].

[[File:loess.jpg|thumb|left|Loess [7]]]

==Identification==

Silt soil is fine and feels like flour when dry. When silt is wet it becomes a smooth mud that can be easily molded into shapes. When silt soil is very wet, it blends seamlessly with water, and forms puddles of mud [4]. Silt particles are very small, so they have a very smooth [[soil texture]]. Silty soil drains well, but not as quickly as sand. Silts sparkly appearance can be observed using a hand lens. Pure silts are identified by their lack of cohesion. Silts and clays are distinguished by their plasticity [5].

[[File:identification.jpg|thumb|right|[8]]]

==See also==

*[[Clay]]
*[[Loam]]
*[[Founders of Soil Concepts]]
*[[Humus]]
*[[Microorganisms]]
*[[Pedogenesis]]
*[[Soil]]
*[[Soil Textures]]
*[[Soil Properties]]
*[[Jenny Equation]]

==References==

[1]
National Geographic Society. “Silt.” National Geographic Society, 9 Oct. 2012, www.nationalgeographic.org/encyclopedia/silt/.

[2]
Wright, Janet S. "“Desert” loess versus “glacial” loess: quartz silt formation, source areas and sediment pathways in the formation of loess deposits." Geomorphology 36.3-4 (2001): 231-256.

[3]
Wright, J. S., Smith, B. J. & Whalley, W. B. Mechanisms of loess-sized quartz silt production and their relative effectiveness: Laboratory simulations. Geomorphology 23, 15-34 (1998).

[4]
Wentworth, Chester K. "A scale of grade and class terms for clastic sediments." The journal of geology 30.5 (1922): 377-392.

[5]
NRCS, USDA. "National soil survey handbook, title 430-VI." (2007).

[6]
“Silt: Environmental Impact.” Rashid's Blog: An Educational Portal, 8 May 2016, rashidfaridi.com/2016/03/04/silt-environmental-impact/.

Silt

2018-05-09T05:11:16Z

Elsbethd: /* Formation */

==Definition==

[[File:Silty.jpg|thumb|right|Silt [6]]]

Silt is a granular sediment that can be transported and deposited by water, ice, and wind. Silt particles are larger than clay, but smaller than sand. To be classified as silt, a particle must be between .002 to .05 mm [1]. Similarly to [[clay]], sand, and gravel, silt is found in [[soil]]. Silt can also occur as sediment mixed in suspension with water. Because of silt’s spherical shape, it retains a large amount of water. Silty soil is known to be more fertile than other soils, and many species of [[organisms]] thrive in it.

==Formation==

Silt-producing mechanisms include frost shattering (Freeze-Thaw Weathering), comminution during transport, eolian abrasion, salt weathering, and glacial grinding. Windblown silt blankets the land in many parts of the world [2]. Large deposits of silt, such as this, are known as loess. Loess landscapes are usually a sign of past glacial activity, including areas such as the Great Plains. Silt can accumulate quickly in areas that lack vegetation, which can disrupt ecosystems. Silt also settles in still water, resulting in build ups like deltas. The main mineral origin of silt is quartz and feldspar [3].

[[File:loess.jpg|thumb|left|Loess [7]]]

==Identification==

Silt soil is fine and feels like flour when dry. When silt is wet it becomes a smooth mud that can be easily molded into shapes. When silt soil is very wet, it blends seamlessly with water, and forms puddles of mud [4]. Silt particles are very small, so they have a very smooth [[soil texture]]. Silty soil drains well, but not as quickly as sand. Silts sparkly appearance can be observed using a hand lens. Pure silts are identified by their lack of cohesion. Silts and clays are distinguished by their plasticity [5].

==See also==

*[[Clay]]
*[[Loam]]
*[[Founders of Soil Concepts]]
*[[Humus]]
*[[Microorganisms]]
*[[Pedogenesis]]
*[[Soil]]
*[[Soil Textures]]
*[[Soil Properties]]
*[[Jenny Equation]]

==References==

[1]
National Geographic Society. “Silt.” National Geographic Society, 9 Oct. 2012, www.nationalgeographic.org/encyclopedia/silt/.

[2]
Wright, Janet S. "“Desert” loess versus “glacial” loess: quartz silt formation, source areas and sediment pathways in the formation of loess deposits." Geomorphology 36.3-4 (2001): 231-256.

[3]
Wright, J. S., Smith, B. J. & Whalley, W. B. Mechanisms of loess-sized quartz silt production and their relative effectiveness: Laboratory simulations. Geomorphology 23, 15-34 (1998).

[4]
Wentworth, Chester K. "A scale of grade and class terms for clastic sediments." The journal of geology 30.5 (1922): 377-392.

[5]
NRCS, USDA. "National soil survey handbook, title 430-VI." (2007).

[6]
“Silt: Environmental Impact.” Rashid's Blog: An Educational Portal, 8 May 2016, rashidfaridi.com/2016/03/04/silt-environmental-impact/.

2018-05-09T04:40:40Z

Elsbethd: /* Formation */

Silt

2018-05-09T04:23:56Z

Elsbethd:

Silt

2018-05-09T04:12:48Z

Elsbethd: /* Definition */

2018-04-20T06:03:25Z

Elsbethd:

==Definition==

[[File:lorryia-formosa-mite.jpg|thumb|right|Lorryia formosa mite [5]]]
Mites are the most diverse of all arachnids, and among the oldest of all terrestrial animals. Fossils date mites from the early Devonian, nearly 400 million years ago [1.] Belonging to the class Archnida, the term "mite" refers to the several groups in the subclass Acari, but it is not a clade, and excludes the ticks. Mites and ticks are similarly characterized by their bodies being divided into two parts, named the gnathosoma and idiosoma. The three major lineages of mites are recognized as Opilioacariformes, Acariformes and Parasitiformes [1]. 45,000 species of mites have been described, which is believed to be only small 5% of the number of species estimated to be alive today.

==Characteristics==

The Acari have been defined by ''A Manual of Acarology'' to have the following characteristics [1]:

*Hexapod prelarva (lost in Parasitiformes and many derived Acariformes)

*Hexapod larval stage

*Three octopod nymphal stages (variously abbreviated in derived taxa)

*Gnathosoma delimited by a circumcapitular suture

*Palpcoxal endites fused medially forming a hypostome

*Hypostome with rutella or corniculi (lost in many derived Acariformes)

*Loss of external evidence of opisthosomal segmentation, i.e. without tergites or sternites

*Ingestion of particulate food (lost in many derived taxa)

==Taxonomy==

[[File:diversity of acari.jpg|thumb|right|Diversity of Acari [6]]]
Acari have been variously ranked as a group made up of one to seven or more distinct orders. The orders comprise approximately half of the described arachnid diversity. Molecular information from ribosomal DNA is used to expose relationships between groups. The 18 S rRNA gene provides information on relationships among phyla and superphyla, while the ITS2, and the 18S ribosomal RNA and 28S ribosomal RNA genes, show relationships at deeper levels [2]. Recent research has suggested that Acari is polyphyletic [3]. ''A Manual of Acarology'' uses a system of six orders, grouped into three superorders to classify Acari [2]:

*Superorder Opilioacariformes – a small order of large mites with about 20 known species
*Superorder Parasitiformes – ticks and a variety of mites
**Holothyrida - predatory mites from the southern hemisphere
**Ixodida – hard ticks and soft ticks
**Mesostigmata – excess of 65 families and 10,000 described species, including bird mites, phytoseiid mites
***Trigynaspida - large, diverse order
***Monogynaspida - diverse order of parasitic and predatory mites
*Superorder Acariformes – contains over 300 families and over 30, 000 described species
**Trombidiformes – plant parasitic mites (spider mites, peacock mites, gall mites, red-legged earth mites, etc.), snout mites, chiggers, hair follicle mites, velvet mites, water mites, etc.
***Sphaerolichida - small order of mites containing two families
***Prostigmata - large order of sucking mites
**Sarcoptiformes
***Oribatida – oribatid mites, beetle mites, armored mites (also cryptostigmata)
***Astigmatina – stored product, fur, feather, dust, and human itch mites, etc.

==Anatomy==

[[File:mitie.jpg|thumb|right|Basic Mite Anatomy [7]]]
Mite size varies from 0.1 mm to 10 mm in length. They are most closely related to spiders than insects. They have the same characteristics of jointed legs and a chitinous exoskeleton. Acari have an open circulating system, ventral nerve cord, alimentary canal and striated muscles and may also possess Malpighian tubules. Acari lack antennae and mandibles [4]. The acarine body is divided into gnathosoma and idiosoma. The gnathosoma is the part of the body of the Acari comprising the mouth and feeding parts, and the idiosoma bears the legs, the genital and anal openings, and an assortment of tactile and sensory structures.

==References==

[1]
Walter, David Evans, Gerald Krantz, and Evert Lindquist. 1996. Acari. The Mites. Version 13 December 1996. http://tolweb.org/Acari/2554/1996.12.13 inThe Tree of Life Web Project, http://tolweb.org/

[2]
Pepato, Almir R, et al. “Phylogenetic Position of the Acariform Mites: Sensitivity to Homology Assessment under Total Evidence.” BMC Evolutionary Biology, BioMed Central, 2 Aug. 2010, bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-10-235.

[3]
Sanggaard, Kristian W.; Bechsgaard, Jesper S.; Fang, Xiaodong (6 May 2014). "Spider genomes provide insight into composition and evolution of venom and silk". Nature Communications. 5: 3765. Bibcode:2014NatCo...5E3765S. doi:10.1038/ncomms4765. PMC 4273655 Freely accessible. PMID 24801114.

[4]
Dhooria M.S. (2016) Morphology and Anatomy of Acari. In: Fundamentals of Applied Acarology. Springer, Singapore

[5]
“Acari.” Acari - Entomologists' Glossary - Amateur Entomologists' Society (AES), www.amentsoc.org/insects/glossary/terms/acari.

[6]
Wilson, Nixon A. “Acarid.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 27 Dec. 2017, www.britannica.com/animal/acarid.

[7]
NCSU Veterinary Parasitology, parasitology.cvm.ncsu.edu/vmp930/keys/mites/miteterms.html.

Mites

2018-04-20T06:02:22Z

Elsbethd:

==Definition==

[[File:lorryia-formosa-mite.jpg|thumb|right|Lorryia formosa mite [5]]]
Mites are the most diverse of all arachnids, and among the oldest of all terrestrial animals. Fossils date mites from the early Devonian, nearly 400 million years ago [1.] Belonging to the class Archnida, the term "mite" refers to the several groups in the subclass Acari, but it is not a clade, and excludes the ticks. Mites and ticks are similarly characterized by their bodies being divided into two parts, named the gnathosoma and idiosoma. The three major lineages of mites are recognized as Opilioacariformes, Acariformes and Parasitiformes [1]. 45,000 species of mites have been described, which is believed to be only small 5% of the number of species estimated to be alive today.

==Characteristics==

The Acari have been defined by ''A Manual of Acarology'' to have the following characteristics [1]:

*Hexapod prelarva (lost in Parasitiformes and many derived Acariformes)

*Hexapod larval stage

*Three octopod nymphal stages (variously abbreviated in derived taxa)

*Gnathosoma delimited by a circumcapitular suture

*Palpcoxal endites fused medially forming a hypostome

*Hypostome with rutella or corniculi (lost in many derived Acariformes)

*Loss of external evidence of opisthosomal segmentation, i.e. without tergites or sternites

*Ingestion of particulate food (lost in many derived taxa)

==Taxonomy==

[[File:diversity of acari.jpg|thumb|right|Diversity of Acari [6]]]
Acari have been variously ranked as a group made up of one to seven or more distinct orders. The orders comprise approximately half of the described arachnid diversity. Molecular information from ribosomal DNA is used to expose relationships between groups. The 18 S rRNA gene provides information on relationships among phyla and superphyla, while the ITS2, and the 18S ribosomal RNA and 28S ribosomal RNA genes, show relationships at deeper levels [2]. Recent research has suggested that Acari is polyphyletic [3]. ''A Manual of Acarology'' uses a system of six orders, grouped into three superorders to classify Acari [2]:

*Superorder Opilioacariformes – a small order of large mites with about 20 known species
*Superorder Parasitiformes – ticks and a variety of mites
**Holothyrida - predatory mites from the southern hemisphere
**Ixodida – hard ticks and soft ticks
**Mesostigmata – excess of 65 families and 10,000 described species, including bird mites, phytoseiid mites
***Trigynaspida - large, diverse order
***Monogynaspida - diverse order of parasitic and predatory mites
*Superorder Acariformes – contains over 300 families and over 30, 000 described species
**Trombidiformes – plant parasitic mites (spider mites, peacock mites, gall mites, red-legged earth mites, etc.), snout mites, chiggers, hair follicle mites, velvet mites, water mites, etc.
***Sphaerolichida - small order of mites containing two families
***Prostigmata - large order of sucking mites
**Sarcoptiformes
***Oribatida – oribatid mites, beetle mites, armored mites (also cryptostigmata)
***Astigmatina – stored product, fur, feather, dust, and human itch mites, etc.

==Anatomy==

[[File:mitie.jpg|thumb|right|Lorryia formosa mite [5]]]
Mite size varies from 0.1 mm to 10 mm in length. They are most closely related to spiders than insects. They have the same characteristics of jointed legs and a chitinous exoskeleton. Acari have an open circulating system, ventral nerve cord, alimentary canal and striated muscles and may also possess Malpighian tubules. Acari lack antennae and mandibles [4]. The acarine body is divided into gnathosoma and idiosoma. The gnathosoma is the part of the body of the Acari comprising the mouth and feeding parts, and the idiosoma bears the legs, the genital and anal openings, and an assortment of tactile and sensory structures.

==References==

[1]
Walter, David Evans, Gerald Krantz, and Evert Lindquist. 1996. Acari. The Mites. Version 13 December 1996. http://tolweb.org/Acari/2554/1996.12.13 inThe Tree of Life Web Project, http://tolweb.org/

[2]
Pepato, Almir R, et al. “Phylogenetic Position of the Acariform Mites: Sensitivity to Homology Assessment under Total Evidence.” BMC Evolutionary Biology, BioMed Central, 2 Aug. 2010, bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-10-235.

[3]
Sanggaard, Kristian W.; Bechsgaard, Jesper S.; Fang, Xiaodong (6 May 2014). "Spider genomes provide insight into composition and evolution of venom and silk". Nature Communications. 5: 3765. Bibcode:2014NatCo...5E3765S. doi:10.1038/ncomms4765. PMC 4273655 Freely accessible. PMID 24801114.

[4]
Dhooria M.S. (2016) Morphology and Anatomy of Acari. In: Fundamentals of Applied Acarology. Springer, Singapore

[5]
“Acari.” Acari - Entomologists' Glossary - Amateur Entomologists' Society (AES), www.amentsoc.org/insects/glossary/terms/acari.

[6]
Wilson, Nixon A. “Acarid.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 27 Dec. 2017, www.britannica.com/animal/acarid.

[7]
NCSU Veterinary Parasitology, parasitology.cvm.ncsu.edu/vmp930/keys/mites/miteterms.html.

File:Mitie.jpg

2018-04-20T06:00:28Z

Elsbethd:

Mites

2018-04-20T05:58:41Z

Elsbethd:

==Definition==

[[File:lorryia-formosa-mite.jpg|thumb|left|Lorryia formosa mite [5]]]
Mites are the most diverse of all arachnids, and among the oldest of all terrestrial animals. Fossils date mites from the early Devonian, nearly 400 million years ago [1.] Belonging to the class Archnida, the term "mite" refers to the several groups in the subclass Acari, but it is not a clade, and excludes the ticks. Mites and ticks are similarly characterized by their bodies being divided into two parts, named the gnathosoma and idiosoma. The three major lineages of mites are recognized as Opilioacariformes, Acariformes and Parasitiformes [1]. 45,000 species of mites have been described, which is believed to be only small 5% of the number of species estimated to be alive today.

==Characteristics==

The Acari have been defined by ''A Manual of Acarology'' to have the following characteristics [1]:

*Hexapod prelarva (lost in Parasitiformes and many derived Acariformes)

*Hexapod larval stage

*Three octopod nymphal stages (variously abbreviated in derived taxa)

*Gnathosoma delimited by a circumcapitular suture

*Palpcoxal endites fused medially forming a hypostome

*Hypostome with rutella or corniculi (lost in many derived Acariformes)

*Loss of external evidence of opisthosomal segmentation, i.e. without tergites or sternites

*Ingestion of particulate food (lost in many derived taxa)

==Taxonomy==

[[File:diversity of acari.jpg|thumb|right|Diversity of Acari [6]]]
Acari have been variously ranked as a group made up of one to seven or more distinct orders. The orders comprise approximately half of the described arachnid diversity. Molecular information from ribosomal DNA is used to expose relationships between groups. The 18 S rRNA gene provides information on relationships among phyla and superphyla, while the ITS2, and the 18S ribosomal RNA and 28S ribosomal RNA genes, show relationships at deeper levels [2]. Recent research has suggested that Acari is polyphyletic [3]. ''A Manual of Acarology'' uses a system of six orders, grouped into three superorders to classify Acari [2]:

*Superorder Opilioacariformes – a small order of large mites with about 20 known species
*Superorder Parasitiformes – ticks and a variety of mites
**Holothyrida - predatory mites from the southern hemisphere
**Ixodida – hard ticks and soft ticks
**Mesostigmata – excess of 65 families and 10,000 described species, including bird mites, phytoseiid mites
***Trigynaspida - large, diverse order
***Monogynaspida - diverse order of parasitic and predatory mites
*Superorder Acariformes – contains over 300 families and over 30, 000 described species
**Trombidiformes – plant parasitic mites (spider mites, peacock mites, gall mites, red-legged earth mites, etc.), snout mites, chiggers, hair follicle mites, velvet mites, water mites, etc.
***Sphaerolichida - small order of mites containing two families
***Prostigmata - large order of sucking mites
**Sarcoptiformes
***Oribatida – oribatid mites, beetle mites, armored mites (also cryptostigmata)
***Astigmatina – stored product, fur, feather, dust, and human itch mites, etc.

==Anatomy==

Mite size varies from 0.1 mm to 10 mm in length. They are most closely related to spiders than insects. They have the same characteristics of jointed legs and a chitinous exoskeleton. Acari have an open circulating system, ventral nerve cord, alimentary canal and striated muscles and may also possess Malpighian tubules. Acari lack antennae and mandibles [4]. The acarine body is divided into gnathosoma and idiosoma. The gnathosoma is the part of the body of the Acari comprising the mouth and feeding parts, and the idiosoma bears the legs, the genital and anal openings, and an assortment of tactile and sensory structures.

==References==

[1]
Walter, David Evans, Gerald Krantz, and Evert Lindquist. 1996. Acari. The Mites. Version 13 December 1996. http://tolweb.org/Acari/2554/1996.12.13 inThe Tree of Life Web Project, http://tolweb.org/

[2]
Pepato, Almir R, et al. “Phylogenetic Position of the Acariform Mites: Sensitivity to Homology Assessment under Total Evidence.” BMC Evolutionary Biology, BioMed Central, 2 Aug. 2010, bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-10-235.

[3]
Sanggaard, Kristian W.; Bechsgaard, Jesper S.; Fang, Xiaodong (6 May 2014). "Spider genomes provide insight into composition and evolution of venom and silk". Nature Communications. 5: 3765. Bibcode:2014NatCo...5E3765S. doi:10.1038/ncomms4765. PMC 4273655 Freely accessible. PMID 24801114.

[4]
Dhooria M.S. (2016) Morphology and Anatomy of Acari. In: Fundamentals of Applied Acarology. Springer, Singapore

[5]
“Acari.” Acari - Entomologists' Glossary - Amateur Entomologists' Society (AES), www.amentsoc.org/insects/glossary/terms/acari.

[6]
Wilson, Nixon A. “Acarid.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 27 Dec. 2017, www.britannica.com/animal/acarid.

Mites

2018-04-20T05:57:38Z

Elsbethd:

==Definition==

[[File:lorryia-formosa-mite.jpg|thumb|right|Lorryia formosa mite [5]]]
Mites are the most diverse of all arachnids, and among the oldest of all terrestrial animals. Fossils date mites from the early Devonian, nearly 400 million years ago [1.] Belonging to the class Archnida, the term "mite" refers to the several groups in the subclass Acari, but it is not a clade, and excludes the ticks. Mites and ticks are similarly characterized by their bodies being divided into two parts, named the gnathosoma and idiosoma. The three major lineages of mites are recognized as Opilioacariformes, Acariformes and Parasitiformes [1]. 45,000 species of mites have been described, which is believed to be only small 5% of the number of species estimated to be alive today.

==Characteristics==

The Acari have been defined by ''A Manual of Acarology'' to have the following characteristics [1]:

*Hexapod prelarva (lost in Parasitiformes and many derived Acariformes)

*Hexapod larval stage

*Three octopod nymphal stages (variously abbreviated in derived taxa)

*Gnathosoma delimited by a circumcapitular suture

*Palpcoxal endites fused medially forming a hypostome

*Hypostome with rutella or corniculi (lost in many derived Acariformes)

*Loss of external evidence of opisthosomal segmentation, i.e. without tergites or sternites

*Ingestion of particulate food (lost in many derived taxa)

==Taxonomy==

[[File:diversity of acari.jpg|thumb|left|Diversity of Acari [6]]]
Acari have been variously ranked as a group made up of one to seven or more distinct orders. The orders comprise approximately half of the described arachnid diversity. Molecular information from ribosomal DNA is used to expose relationships between groups. The 18 S rRNA gene provides information on relationships among phyla and superphyla, while the ITS2, and the 18S ribosomal RNA and 28S ribosomal RNA genes, show relationships at deeper levels [2]. Recent research has suggested that Acari is polyphyletic [3]. ''A Manual of Acarology'' uses a system of six orders, grouped into three superorders to classify Acari [2]:

*Superorder Opilioacariformes – a small order of large mites with about 20 known species
*Superorder Parasitiformes – ticks and a variety of mites
**Holothyrida - predatory mites from the southern hemisphere
**Ixodida – hard ticks and soft ticks
**Mesostigmata – excess of 65 families and 10,000 described species, including bird mites, phytoseiid mites
***Trigynaspida - large, diverse order
***Monogynaspida - diverse order of parasitic and predatory mites
*Superorder Acariformes – contains over 300 families and over 30, 000 described species
**Trombidiformes – plant parasitic mites (spider mites, peacock mites, gall mites, red-legged earth mites, etc.), snout mites, chiggers, hair follicle mites, velvet mites, water mites, etc.
***Sphaerolichida - small order of mites containing two families
***Prostigmata - large order of sucking mites
**Sarcoptiformes
***Oribatida – oribatid mites, beetle mites, armored mites (also cryptostigmata)
***Astigmatina – stored product, fur, feather, dust, and human itch mites, etc.

==Anatomy==

Mite size varies from 0.1 mm to 10 mm in length. They are most closely related to spiders than insects. They have the same characteristics of jointed legs and a chitinous exoskeleton. Acari have an open circulating system, ventral nerve cord, alimentary canal and striated muscles and may also possess Malpighian tubules. Acari lack antennae and mandibles [4]. The acarine body is divided into gnathosoma and idiosoma. The gnathosoma is the part of the body of the Acari comprising the mouth and feeding parts, and the idiosoma bears the legs, the genital and anal openings, and an assortment of tactile and sensory structures.

==References==

[1]
Walter, David Evans, Gerald Krantz, and Evert Lindquist. 1996. Acari. The Mites. Version 13 December 1996. http://tolweb.org/Acari/2554/1996.12.13 inThe Tree of Life Web Project, http://tolweb.org/

[2]
Pepato, Almir R, et al. “Phylogenetic Position of the Acariform Mites: Sensitivity to Homology Assessment under Total Evidence.” BMC Evolutionary Biology, BioMed Central, 2 Aug. 2010, bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-10-235.

[3]
Sanggaard, Kristian W.; Bechsgaard, Jesper S.; Fang, Xiaodong (6 May 2014). "Spider genomes provide insight into composition and evolution of venom and silk". Nature Communications. 5: 3765. Bibcode:2014NatCo...5E3765S. doi:10.1038/ncomms4765. PMC 4273655 Freely accessible. PMID 24801114.

[4]
Dhooria M.S. (2016) Morphology and Anatomy of Acari. In: Fundamentals of Applied Acarology. Springer, Singapore

[5]
“Acari.” Acari - Entomologists' Glossary - Amateur Entomologists' Society (AES), www.amentsoc.org/insects/glossary/terms/acari.

[6]
Wilson, Nixon A. “Acarid.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 27 Dec. 2017, www.britannica.com/animal/acarid.