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'''Opiliones''' are commonly referred to as harvest men, but are also known as daddy long legs, granddaddy long legs, harvest spiders, shepherd spiders, or phalangids.
Opiliones were once scientifically classified as ''phalangida'', which you may see used in older literature. The more common name "daddy long legs" may also be mistakenly used to refer to the unrelated crane fly (''Tipulidae'') and the cellar spider (''Pholcidae'').[http://www.newworldencyclopedia.org/p/index.php?title=Opiliones&oldid=1016769.] They are known for grouping in large masses of unrelated individuals resembling fur.


 
[[File:0 OXzI69wALTmoxvJrPEBFbuOTM OcO0rVvYWw7k5K8.jpg|500px|right|''A Congregation of Opliliones''|thumb]]
== Common Names ==
----
Aka Harvest Men or Daddy Long legs.Daddy-long-legs/Daddy-longlegs/Daddy Long-legs, Granddaddy-long-legs, Harvest Spiders, Shepherd Spiders, Phalangids, Opilionids.
The former scientific name for Opiliones was Phalangida and this name still often appears in the literature. The common name "daddy longlegs" also is used for the crane fly (Tipulidae) and the cellar spider (Pholcidae) (Crawford 2005).[encyclopedia]


== Description ==
== Description ==


<q>Opiliones are delicate, shy forms that are among the largest of arachnids in woodlands.[class book]
Opiliones have been in evolutionary stasis since the early Devonian period.[me] They are delicate, shy forms, and are among the largest of arachnids in woodlands [2]. Like other arachnids, they possess 8 legs, 2 pedipalps and 2 chelicerae.[8]
'''Opiliones''' can be differentiated from spiders by looking closely at what appears to be one body segment, but is actually two fused segments, which is consistent with spiders. Daddy long-legs do not possess silk glands, and can not spin webs. Unlike spiders, harvest men lack venom glands associated with their chelicerae. True of all arachnids, fertilization is by direct contact with female. Males of most taxa possess a penis, which is also referred to as a pene, or an aedagus. [3] Opiliones unlike spiders do not possess a book lung, instead their respiratory system is trachial, similar to [[acari]] and [[solifugea]].[8]


Easily separated from spiders by the broad fusion of the two body segments, so that the body appears to be composed of a singular segment. Harvestmen do not possess silk glands, and can't spin webs. Unlike spiders, harvestmen lack venom glands associated with their chelicerae (mouthparts). Uniquely among the arachnids fertilization is direct: males of most taxa possess a penis (also referred to in the literature as pene, aedagus or intromittent organ).[bug guide]
Harvest men are known for their exceptionally long walking legs compared to body size, although some species do have shorter legs. In more advanced species of harvest men, the first five abdominal segments are often fused into a dorsal shield called the scutum, which is normally fused with the carapace. Sometimes this shield is only present in males.They have a second pair of legs that are longer than the others and work as antennae. This can be hard to see in short-legged species.


Harvestmen are known for their exceptionally long walking legs, compared to body size, although there are also short-legged species. The difference between harvestmen and spiders is that in harvestmen the two main body sections (the abdomen with ten segments and the cephalothorax—or the prosoma and opisthosoma) are broadly joined, so that they appear to be one oval structure; they also have no venom or silk glands. In more advanced species of harvestment, the first five abdominal segments are often fused into a dorsal shield called the scutum, which is normally fused with the carapace. Sometimes this shield is only present in males. The two most posterior abdominal segments can be reduced or separated in the middle on the surface to form two plates lying next to each other. The second pair of legs are longer than the others and work as antennae. This can be hard to see in short-legged species.
Typical body lengths do not exceed 7 millimeters, with some species smaller than one millimeter. The largest species ''Trogulus Torosus'' can reach a length of 22 millimeters. [4] Leg spans are much larger and some species can exceed 160 millimeters. [1]
 
Typical body length does not exceed 7 millimeters (about 5/16 inch), with some species smaller than one millimeter, although the largest species Trogulus torosus (Trogulidae) can reach a length of 22 millimeters (Pinto-da-Rocha et al. 2007). However, leg span is much larger and can exceed 160 millimeters (over 6 inches).[encyclopedia]


== Range and Habitat ==
== Range and Habitat ==


Global, except Antarctica-range
Opiliones are found globally with the exception of Antarctica but are largely restricted to damp shady places. Nymphs are especially susceptible to dehydration. [8]


forests, grasslands, wetlands, mountains, caves, chaparral, and anthropogenic habitats
Forests, grasslands, wetlands, mountains, caves, chaparral, and even human dwellings make for suitable Opilione habitats.


As expected, Tropical realms concentrate most of the opilionofauna. The Neotropics and Indo-Malayan are
Tropical systems hold the most '''Opilione''' species. The neo-tropics and Indo-Malayan are
the most diverse realms with respectively 2691 species (41%) and 1337 species (20%). That is, together they
the most diverse realms with respectively 2691 species (41%) and 1337 species (20%). These two tropical regions are then home to
have almost 2/3 of the Opiliones. The third most diverse realm is the Palearctic with 819 species (13%),
almost 2/3 of the Opiliones. The third most diverse realm is the pale arctic with 819 species (13%),
mostly because of its sheer size. Afrotropical has only 745 species (11%). Australasia with 564 species has
mostly because of its sheer size. The African tropics have 745 species (11%). Australasia with 564 species has
9% and Nearctic with 379 species has less than 6%. The total sum of species of all realms is slightly different
9% and Ne-arctic with 379 species has less than 6%. The total sum of species of all realms is slightly different
from the total Opiliones because a few species are shared between realms.[zootaxa correspondence]
from the total Opiliones because a few species are shared between regions. [5]


== Species ==
== Species ==
There are an estimated 6600 species worldwide that are classified in 4 sub-orders and then divided into 45 families.
=== Suborders ===


>6600 species worldwide arranged into ~45 families of 4 suborders (of which Laniatores is by far the largest, with >4100 species) [Bug page]
[[File:Lani.jpg|200px|left|''Laniatore F. Phalangodidae'' [3] |thumb]]


ex.Laniatores: these are the stout, spiny harvestmen found in the Tropics, which may reach very large size.
[[File:Trogulushirtus,adult,Croatia,Konavle4.300a.JPG|200px|right|''Dyspnoi Trogulushirtus'' [2011 Axel Schönhofer] 
Dyspnoi: these are Temperate Old World species, dull-colored and short-legged. Some species may have bizarre ocular ornamentation.
|thumb]]
Eupnoi: these are the daddy-longlegs, familiar to Europeans and Americans. They have coriaceous tegument, delicate pedipalps, legs often very thin and long. There is a a myriad of tropical species (Gagrellinae), which may have mettalic shines, intricate honeycomb patterns of granulation, and striped/dotted multicolored hues of blue, red, green, yellow.
Cyphs: these are the minute acari-like Opiliones which were undersampled until the last decades, when intensive studies made them much better known[museum classification page]


== Activity ==
[[File:Gagrellinae_-_Philippines.jpg|200px|left|''Eupnoi'' Gagrellinae-Phillipines [4]|thumb]]


Most species are nocturnal and colored in hues of brown, although a number of diurnal species are known, some of which have vivid patterns in yellow, green, and black with varied reddish and blackish mottling and reticulation.[wikireal]
[[File:Cymph.jpg|200px|right|''Cyphophthalmi''|thumb]]


They are active predators during the daylight but tend to be crepuscular. [our book]
==== Laniatores ====
 
''Laniatores'' are by far the largest suborder with >4100 species).[3] These stout, spiny '''Opiliones''' are typically short legged with hard plates, with many reaching large sizes. Most species in this sub-order depend on warm moist habitats. Given that majority of ''Laniatores'' prefer the tropic climate, it is not uncommon to find them in temperate forests as well. [7]
==== Dyspnoi ====
The sub-order is divided into 8 families consisting of 340 species. They are temperate old world species that are dull-colored and short-legged. Some species may have odd ocular ornamentation. The small number of species of this sub-order, compared to ''Laniatores'', have a more restricted range and are only found in temperate zones with few exceptions.
==== Eupnoi ====
These are the '''Opiliones''' familiar to Europeans and Americans that have earned them the order the name daddy long legs. Their legs are often very thin and long. Several of the tropical species ex. ''Gagrellinae'', may have metallic shines, intricate honeycomb patterns of vascular tissues, and striped/dotted multicolored hues of blue, red, green, yellow.
==== Cyphophthalmi ====
These Opiliones are smaller than the ''Euponoi'' members and resemble minute [[Acari]]. ''Cyphophthalmi'' is the least studied sub-order with only 200 species, but this is thought to be a major underestimate. [6] Their small size and wide distribution have contributed to their lack of study. ''Cyphophthalmi'' species can tolerate many climate conditions and are found on all the continents except Antarctica.
 
 
== Activity & Diet ==
 
Species vary from omnivorous to carnivorous and eat [[insects]], vegetation and fungi, while some are can be [[coprophagous]]. they are by and large opportunistic feeders and will move between habitats looking for food, some species though are predatory
. Most species tend to be nocturnal, although a number of diurnal species have been identified. Some of the predaceous Opiliones are also diurnal, but most are known to be crepuscular.[2] Opiliones feed by ingesting large chunks or particles of prey rather than predigesting or liquefying their prey.[8]


== Reproduction ==
== Reproduction ==


Although parthenogenetic species do occur, most harvestmen reproduce sexually. Mating involves direct copulation, rather than the deposition of a spermatophore. The males of some species offer a secretion from their chelicerae to the female before copulation. Sometimes the male guards the female after copulation, and in many species the males defend territories.
Although parthenogenic species do occur, most harvest men reproduce sexually. Mating involves direct copulation. The males of some species offer a secretion from their chelicerae to the female before copulation. Sometimes the male guards the female after sex.
The females lay eggs shortly after mating, or up to months later. Some species build nests for this purpose. A unique feature of harvestmen is that in some species the male is solely responsible for guarding the eggs resulting from multiple partners, often against egg-eating females, and subjecting the eggs to regular cleaning. The eggs can hatch anytime after the first 20 days, up to almost half a year after being laid. Harvestmen need from four to eight nymphal stages to reach maturity, with six the most common (Pinto-da-Rocha et al. 2007).[encyclopedia]
The females lay eggs shortly after mating, or up to months later. Some species build nests for this purpose. A unique feature of some species is parental care of the offspring, with a few even displaying paternal care. The eggs can hatch anytime after the first 20 days, up to almost half a year after being laid. Daddy long legs need have about four to eight nymphal stages before reaching maturity, but six is the most common. [4]


== Noted ==
== Noted ==


Although harvest men are a fascinating group of arachnids the dramatic increase in environmental disturbance around the world especially in tropical regions may have driven many species to extinction even before there formal description by taxonomists. Human activities including pesticide use forestry operations air and soil pollution fire and even the introduction of domestic animals have a tremendous impact on the habitats they depend on. All formerly considered endangered are most were cave dwellers who are particularly sensitive to disturbances of habitat [Harvard bookHarvestmen: The Biology of Opiliones
Although harvest men are a fascinating group of arachnids, the dramatic increase in environmental disturbances around the world, especially in tropical regions, may have driven many species to extinction even before the formal descriptions by taxonomists. Human activities including pesticide use, forestry operations, air and [[soil]] pollution, fire, and even the introduction of domestic [[animals]] have a tremendous impact on the habitats they depend on. All the formerly considered endangered were cave dwellers who are particularly sensitive to disturbances of habitat. [4]
Ricardo Pinto-Da-Rocha, Glauco Machado, and Gonzalo Giribet (eds.). 2007. Harvard University Press.]
Contrary to popular belief daddy-long legs species do not contain the world's most powerful venom or any at all for that matter! [7]


Myth: The daddy-longlegs has the world's most powerful venom, but fortunately its jaws (fangs) are so small that it can't bite you.
== References ==
Fact: That is a full-fledged Urban Legend, with no basis in fact whatever. This legend is so widespread that many people believe it who should really know better, including some teachers and TV documentary producers.


Three different unrelated groups are called "daddy-longlegs." Harvestmen have no venom of any kind. None at all! Same with crane flies . Pholcid spiders have venom (like almost all spiders) but there's nothing special about it; in fact, a recent study showed that pholcid venom is unusually weak in its effect on insects. This myth is debunked at greater length on Rick Vetter's website.[Burke museum paper]
----
[1] Opiliones. (2018, December 21). New World Encyclopedia, . Retrieved 21:30, April 20, 2019. https://www.newworldencyclopedia.org/p/index.php?title=Opiliones&oldid=1016769.


== References ==
[2] Coleman, David C., et al. Fundamentals of Soil [[Ecology]]. Academic Press, 2018. {{ISBN 978-0-12-805251-8}}
 
[3] Bartlett, Troy. “Order Opiliones - Harvestmen.” Order Opiliones - Harvestmen - BugGuide.Net, 16 Feb. 2004, bugguide.net/node/view/2405#id.
https://bugguide.net/node/view/2405#id
[4] Pinto-da-Rocha, Ricardo, et al. Harvestmen: the Biology of Opiliones. Harvard University Press, 2007.
[5] Kury, Adriano. (2013). Order Opiliones Sundevall, 1833. Zootaxa. 3703. 27-33. https://www.researchgate.net/publication/293635734_Order_Opiliones_Sundevall_1833
 
[6] Kury, A.B. (2000 onwards) Classification of Opiliones. Museu Nacional/UFRJ website. Online at: http://www.museunacional.ufrj.br/mndi/Aracnologia/opiliones.html
 
[7] “Myth: Daddy-Longlegs Would Be Deadly but...” Burke Museum, 8 Apr. 2016,
https://www.burkemuseum.org/blog/myth-daddy-longlegs-would-be-deadly.
 
[8] Cowles, J. 2018. Harvestmen:: Opiliones. Pages 102–113 Amazing Arachnids. Princeton University Press.
 
 
== External Links ==


----
'''Opiliones Wiki Site''' https://opiliones.fandom.com/wiki/Adriano_B._Kury

Latest revision as of 11:04, 5 May 2021

Opiliones are commonly referred to as harvest men, but are also known as daddy long legs, granddaddy long legs, harvest spiders, shepherd spiders, or phalangids. Opiliones were once scientifically classified as phalangida, which you may see used in older literature. The more common name "daddy long legs" may also be mistakenly used to refer to the unrelated crane fly (Tipulidae) and the cellar spider (Pholcidae).[1] They are known for grouping in large masses of unrelated individuals resembling fur.

A Congregation of Opliliones

Description

Opiliones have been in evolutionary stasis since the early Devonian period.[me] They are delicate, shy forms, and are among the largest of arachnids in woodlands [2]. Like other arachnids, they possess 8 legs, 2 pedipalps and 2 chelicerae.[8] Opiliones can be differentiated from spiders by looking closely at what appears to be one body segment, but is actually two fused segments, which is consistent with spiders. Daddy long-legs do not possess silk glands, and can not spin webs. Unlike spiders, harvest men lack venom glands associated with their chelicerae. True of all arachnids, fertilization is by direct contact with female. Males of most taxa possess a penis, which is also referred to as a pene, or an aedagus. [3] Opiliones unlike spiders do not possess a book lung, instead their respiratory system is trachial, similar to acari and solifugea.[8]

Harvest men are known for their exceptionally long walking legs compared to body size, although some species do have shorter legs. In more advanced species of harvest men, the first five abdominal segments are often fused into a dorsal shield called the scutum, which is normally fused with the carapace. Sometimes this shield is only present in males.They have a second pair of legs that are longer than the others and work as antennae. This can be hard to see in short-legged species.

Typical body lengths do not exceed 7 millimeters, with some species smaller than one millimeter. The largest species Trogulus Torosus can reach a length of 22 millimeters. [4] Leg spans are much larger and some species can exceed 160 millimeters. [1]

Range and Habitat

Opiliones are found globally with the exception of Antarctica but are largely restricted to damp shady places. Nymphs are especially susceptible to dehydration. [8]

Forests, grasslands, wetlands, mountains, caves, chaparral, and even human dwellings make for suitable Opilione habitats.

Tropical systems hold the most Opilione species. The neo-tropics and Indo-Malayan are the most diverse realms with respectively 2691 species (41%) and 1337 species (20%). These two tropical regions are then home to almost 2/3 of the Opiliones. The third most diverse realm is the pale arctic with 819 species (13%), mostly because of its sheer size. The African tropics have 745 species (11%). Australasia with 564 species has 9% and Ne-arctic with 379 species has less than 6%. The total sum of species of all realms is slightly different from the total Opiliones because a few species are shared between regions. [5]

Species

There are an estimated 6600 species worldwide that are classified in 4 sub-orders and then divided into 45 families.

Suborders

Laniatore F. Phalangodidae [3]
Dyspnoi Trogulushirtus [2011 Axel Schönhofer]
Eupnoi Gagrellinae-Phillipines [4]
Cyphophthalmi

Laniatores

Laniatores are by far the largest suborder with >4100 species).[3] These stout, spiny Opiliones are typically short legged with hard plates, with many reaching large sizes. Most species in this sub-order depend on warm moist habitats. Given that majority of Laniatores prefer the tropic climate, it is not uncommon to find them in temperate forests as well. [7]

Dyspnoi

The sub-order is divided into 8 families consisting of 340 species. They are temperate old world species that are dull-colored and short-legged. Some species may have odd ocular ornamentation. The small number of species of this sub-order, compared to Laniatores, have a more restricted range and are only found in temperate zones with few exceptions.

Eupnoi

These are the Opiliones familiar to Europeans and Americans that have earned them the order the name daddy long legs. Their legs are often very thin and long. Several of the tropical species ex. Gagrellinae, may have metallic shines, intricate honeycomb patterns of vascular tissues, and striped/dotted multicolored hues of blue, red, green, yellow.

Cyphophthalmi

These Opiliones are smaller than the Euponoi members and resemble minute Acari. Cyphophthalmi is the least studied sub-order with only 200 species, but this is thought to be a major underestimate. [6] Their small size and wide distribution have contributed to their lack of study. Cyphophthalmi species can tolerate many climate conditions and are found on all the continents except Antarctica.


Activity & Diet

Species vary from omnivorous to carnivorous and eat insects, vegetation and fungi, while some are can be coprophagous. they are by and large opportunistic feeders and will move between habitats looking for food, some species though are predatory . Most species tend to be nocturnal, although a number of diurnal species have been identified. Some of the predaceous Opiliones are also diurnal, but most are known to be crepuscular.[2] Opiliones feed by ingesting large chunks or particles of prey rather than predigesting or liquefying their prey.[8]

Reproduction

Although parthenogenic species do occur, most harvest men reproduce sexually. Mating involves direct copulation. The males of some species offer a secretion from their chelicerae to the female before copulation. Sometimes the male guards the female after sex. The females lay eggs shortly after mating, or up to months later. Some species build nests for this purpose. A unique feature of some species is parental care of the offspring, with a few even displaying paternal care. The eggs can hatch anytime after the first 20 days, up to almost half a year after being laid. Daddy long legs need have about four to eight nymphal stages before reaching maturity, but six is the most common. [4]

Noted

Although harvest men are a fascinating group of arachnids, the dramatic increase in environmental disturbances around the world, especially in tropical regions, may have driven many species to extinction even before the formal descriptions by taxonomists. Human activities including pesticide use, forestry operations, air and soil pollution, fire, and even the introduction of domestic animals have a tremendous impact on the habitats they depend on. All the formerly considered endangered were cave dwellers who are particularly sensitive to disturbances of habitat. [4] Contrary to popular belief daddy-long legs species do not contain the world's most powerful venom or any at all for that matter! [7]

References

[1] Opiliones. (2018, December 21). New World Encyclopedia, . Retrieved 21:30, April 20, 2019. https://www.newworldencyclopedia.org/p/index.php?title=Opiliones&oldid=1016769.

[2] Coleman, David C., et al. Fundamentals of Soil Ecology. Academic Press, 2018. Template:ISBN 978-0-12-805251-8

[3] Bartlett, Troy. “Order Opiliones - Harvestmen.” Order Opiliones - Harvestmen - BugGuide.Net, 16 Feb. 2004, bugguide.net/node/view/2405#id. https://bugguide.net/node/view/2405#id

[4] Pinto-da-Rocha, Ricardo, et al. Harvestmen: the Biology of Opiliones. Harvard University Press, 2007.

[5] Kury, Adriano. (2013). Order Opiliones Sundevall, 1833. Zootaxa. 3703. 27-33. https://www.researchgate.net/publication/293635734_Order_Opiliones_Sundevall_1833

[6] Kury, A.B. (2000 onwards) Classification of Opiliones. Museu Nacional/UFRJ website. Online at: http://www.museunacional.ufrj.br/mndi/Aracnologia/opiliones.html

[7] “Myth: Daddy-Longlegs Would Be Deadly but...” Burke Museum, 8 Apr. 2016, https://www.burkemuseum.org/blog/myth-daddy-longlegs-would-be-deadly.

[8] Cowles, J. 2018. Harvestmen:: Opiliones. Pages 102–113 Amazing Arachnids. Princeton University Press.


External Links

Opiliones Wiki Site https://opiliones.fandom.com/wiki/Adriano_B._Kury

Retrieved from "http://soil.evs.buffalo.edu/index.php?title=Opiliones&oldid=6683"