Editing Plecoptera

{{Short description|Order of insects}}
{{For |the genus of moths |Plecoptera (moth){{!}}''Plecoptera'' (moth)}}
{{Automatic taxobox
| fossil_range = {{fossil_range|299|0}} [[Permian]]–Recent
| image = Eusthenia sp.jpg
| image_caption = ''[[Eusthenia]]'' sp.
| display_parents = 4
| taxon = Plecoptera
| authority = [[Hermann Burmeister|Burmeister]], 1839
| subdivision_ranks = Suborders
| subdivision = mostly [[Arctoperlaria]]: see [[#Systematics|text]]
}}

'''Plecoptera''' is an [[order (biology)|order]] of [[insect]]s, commonly known as '''stoneflies'''. Some 3,500 species are described worldwide,<ref>{{cite book |author=Romolo Fochetti |author2=José Manuel Tierno de Figueroa |date=2008|name-list-style=amp |chapter=Global diversity of stoneflies (Plecoptera; Insecta) in freshwater |series=Developments in Hydrobiology|orig-date=Originally published in ''Hydrobiologia'' Vol. 595 in 2008|volume=198|pages=365–377 |doi=10.1007/978-1-4020-8259-7_39 |title=Freshwater Animal Diversity Assessment |hdl=2067/1437 |editor1=E. V. Balian |editor2=C. Lévêque |editor3=H. Segers |editor4=K. Martens |isbn=978-1-4020-8258-0 }}</ref> with new species still being discovered. Stoneflies are found worldwide, except Antarctica.<ref>Brittain, 1987</ref> Stoneflies are believed to be one of the most primitive groups of [[Neoptera]], with close relatives identified from the [[Carboniferous]] and Lower [[Permian]] geological periods, while true stoneflies are known from fossils only a bit younger. Their modern diversity, however, apparently is of [[Mesozoic]] origin.<ref name="Zwick">{{cite journal |author=Peter Zwick |year=2000 |title=Phylogenetic system and zoogeography of the Plecoptera |journal=[[Annual Review of Entomology]] |volume=45 |pages=709–746 |doi=10.1146/annurev.ento.45.1.709|pmid=10761594}}</ref>

Plecoptera are found in both the [[Southern hemisphere|Southern]] and [[Northern Hemisphere]]s, and the populations are quite distinct, although the [[evolution]]ary evidence suggests species may have crossed the [[equator]] on a number of occasions before once again becoming geographically isolated.<ref name="Zwick"/><ref>{{cite book |author=H. B. N. Hynes |year=1993 |title=Adults and Nymphs of British Stoneflies |publisher=[[Freshwater Biological Association]] |isbn=978-0-900386-28-2}}</ref>

All species of Plecoptera are intolerant of [[water pollution]], and the presence of their [[nymph (biology)|nymph]]s in a stream or still water is usually an indicator of good or excellent water quality.<ref>{{cite web|last=Nelson|first=Riley|title=Clean water has bugs in it, says BYU Biology Professor Riley Nelson|url=http://news.byu.edu/archive13-may-stoneflies.aspx|access-date=16 May 2013|archive-url=https://web.archive.org/web/20150906131524/http://news.byu.edu/archive13-may-stoneflies.aspx|archive-date=6 September 2015|url-status=dead}}</ref>  

==Description and ecology==
[[File:SteinfliegenLarve2.JPG|left|thumb|[[nymph (biology)|Nymph]] of a golden stonefly, Plecoptera, Perlidae]] 
[[File:Stonefly - dinotoperla.jpg|thumb|left|''[[Dinotoperla]]'' [[imago]] (adult)<br />([[Gripopterygidae]]: [[Dinotoperlinae]])]]

Stoneflies have a generalized anatomy, with few specialized features compared to other insects. They have simple [[insect mouthparts|mouthparts]] with chewing [[mandible (arthropod)|mandibles]], long, multiple-segmented [[antenna (biology)|antennae]], large [[compound eye]]s, and two or three [[ocelli]]. The legs are robust, with each ending in two claws. The [[abdomen]] is relatively soft, and may include remnants of the nymphal gills even in the adult. Both [[Nymph (biology)|nymph]]s and adults have long, paired [[cercus|cerci]] projecting from the tip of their abdomens.<ref name=IIBD>{{cite book |author= Hoell, H.V. |author2= Doyen, J.T. |author3= Purcell, A.H. |name-list-style=amp |year=1998 |title=Introduction to Insect Biology and Diversity |edition=2nd |publisher= Oxford University Press |pages= 383–386|isbn= 978-0-19-510033-4}}</ref>

The name "Plecoptera" literally means "[[braid]]ed-wings", from the [[Ancient Greek]] ''plekein'' (πλέκειν, "to braid") and ''pteryx'' (πτέρυξ, "wing").<ref>{{cite book |author=S. C. Woodhouse |year=1910 |title=English-Greek Dictionary - a Vocabulary of the Attic Language |publisher=George Routledge & Sons |location=London |url=https://www.lib.uchicago.edu/efts/Woodhouse/}}</ref> This refers to the complex venation of their two pairs of [[insect wings|wings]], which are [[biological membrane|membranous]] and fold flat over their backs. Stoneflies are generally not strong fliers, and some species are entirely wingless.

A few wingless species, such as the [[Lake Tahoe benthic stonefly]] (''[[Capnia lacustra|"Capnia" lacustra]]''{{#tag:ref|The genus ''[[Capnia]]'' is not [[monophyletic]] and this species is suspected to belong elsewhere.<ref>{{cite web |author=C. Riley Nelson |work=[[Tree of Life Web Project]] |url=http://tolweb.org/Capniidae/13943/1996.01.01 |title=Capniidae. Winter Stoneflies |date=January 1, 1996 |access-date=July 31, 2008}}</ref>|group=Note}}) or ''[[Baikaloperla]]'', are the only known insects, perhaps with the exception of ''[[Halobates]]'', that are exclusively aquatic from birth to death.<ref>{{cite book |author=E. M. Holst |year=2000 |chapter=Lake Tahoe benthic stonefly (''Capnia lacustra'') |editor1=D. D. Murhy |editor2=C. M. Knopp |url=http://www.fs.fed.us/psw/publications/documents/gtr-175/ |title=Lake Tahoe Watershed Assessment |pages=O–118 – O–120 |publisher=[[United States Department of Agriculture]] |chapter-url=http://www.fs.fed.us/psw/publications/documents/gtr-175/gtr-175-appendixO.pdf |format=[[PDF]]}}</ref> Some [[true water bug]]s (Nepomorpha) may also be fully aquatic for their entire lives, but can leave the water to travel.

The nymphs (technically, "naiads") are aquatic and live in the [[benthic zone]] of well-oxygenated lakes and streams. A few species found in New Zealand and nearby islands have terrestrial nymphs, but even these inhabit only very moist environments. The nymphs physically resemble wingless adults, but often have external gills, which may be present on almost any part of the body. Nymphs can acquire oxygen via diffusing through the exoskeleton, or through gills located on behind the head, on the thorax, or around the anus.<ref>{{Cite web|title = ENT 425 {{!}} General Entomology {{!}} Resource Library {{!}} Compendium [plecoptera]|url = https://www.cals.ncsu.edu/course/ent425/library/compendium/plecoptera.html|website = www.cals.ncsu.edu|access-date = 2016-02-23}}</ref> Due to their nymph's requirement for well oxygenated water, the species is very sensitive to water pollution. This makes them important indicators for water quality.<ref>{{Cite web|title = Plecoptera - Stoneflies -- Discover Life|url = http://www.discoverlife.org/mp/20q?search=Plecoptera|website = www.discoverlife.org|access-date = 2016-02-23}}</ref> Most species are herbivorous as nymphs, feeding on submerged leaves and benthic algae, but many are hunters of other aquatic arthropods.<ref name="IIBD" />
{{Further|Mesoleuctra}}

== Life cycle ==
The female can lay up to one thousand eggs. It will fly over the water and drop the eggs in the water. It also may hang on a rock or branch. Eggs are covered in a sticky coating which allows them to adhere to rocks without being swept away by swift currents.<ref name=":0">{{Cite web|url=https://www.cals.ncsu.edu/course/ent425/library/compendium/plecoptera.html|title=ENT 425 {{!}} General Entomology {{!}} Resource Library {{!}} Compendium [plecoptera]|website=www.cals.ncsu.edu|access-date=2016-04-12}}</ref> The eggs typically take two to three weeks to hatch, but some species undergo [[diapause]], with the eggs remaining dormant throughout a dry season, and hatching only when conditions are suitable.<ref name="IIBD" />

The insects remain in the nymphal form for one to four years, depending on species, and undergo from 12 to 36 [[ecdysis|molts]] before emerging and becoming terrestrial as adults.<ref>{{Cite web|url=http://bugguide.net/node/view/76|title=Order Plecoptera - Stoneflies - BugGuide.Net|website=bugguide.net|access-date=2016-04-12}}</ref> Before becoming adults, nymphs will leave the water, attach to a fixed surface and molt one last time.

The adults generally only survive for a few weeks, and emerge only during specific times of the year when resources are optimal. Some do not feed at all, but those that do are herbivorous.<ref name="IIBD" /> Adults are not strong fliers and generally stay near the stream or lake they hatched from.<ref name=":0" />

==Phylogeny==

A summary of the phylogeny of stoneflies is shown below. While the Antarctoperlaria, Arctoperlaria, Euholognatha, Systellognatha are well supported, several further relationships are disputed.<ref>{{cite journal |last1=Ding |first1=Shuangmei |last2=Li |first2=Weihai |last3=Wang |first3=Ying |last4=Cameron |first4=Stephen L. |last5=Murányi |first5=Dávid |last6=Yang |first6=Ding |title=The phylogeny and evolutionary timescale of stoneflies (Insecta: Plecoptera) inferred from mitochondrial genomes |journal=Molecular Phylogenetics and Evolution |date=June 2019 |volume=135 |pages=123–135 |doi=10.1016/j.ympev.2019.03.005 |pmid=30876966 |bibcode=2019MolPE.135..123D }}</ref><ref>{{cite journal |last1=South |first1=Eric J. |last2=Skinner |first2=Rachel K. |last3=DeWalt |first3=R. Edward |last4=Kondratieff |first4=Boris C. |last5=Johnson |first5=Kevin P. |last6=Davis |first6=Mark A. |last7=Lee |first7=Jonathan J. |last8=Durfee |first8=Richard S. |title=Phylogenomics of the North American Plecoptera |journal=Systematic Entomology |date=January 2021 |volume=46 |issue=1 |pages=287–305 |doi=10.1111/syen.12462 |bibcode=2021SysEn..46..287S }}</ref><ref>{{cite journal |last1=Zhao |first1=Meng-Yuan |last2=Huo |first2=Qing-Bo |last3=Du |first3=Yu-Zhou |title=Molecular phylogeny inferred from the mitochondrial genomes of Plecoptera with Oyamia nigribasis (Plecoptera: Perlidae) |journal=Scientific Reports |date=December 2020 |volume=10 |issue=1 |page=20955 |doi=10.1038/s41598-020-78082-y |pmid=33262442 |pmc=7708463 }}</ref> Some families have only been analyzed by one study (indicated by dashed lines) and their placement may change in the near future.

{{clade
|label1='''Plecoptera'''
|1={{clade
   |label1=Antarctoperlaria
   |1={{clade
      |1={{clade
         |1=[[Austroperlidae]] [[File:Austroperla cyrene.jpg|60px]]
         |state1=dashed
         |2=[[Gripopterygidae]] [[File:Stonefly - dinotoperla.jpg|60px]]
         }}
      |2={{clade
         |1=[[Diamphipnoidae]] [[File:Diamphipnopsis virescentipennis CCDB-32127-G03+1551475506.jpg|30px]]
         |2=[[Eustheniidae]] [[File:Eusthenia nothofagi.jpg|Austroperla_cyrene|50px]]
         }}
      }}
   |label2=[[Arctoperlaria]]
   |2={{clade
      |label1=Euholognatha
      |1={{clade
         |1=[[Leuctridae]] [[File:Leuctra.inermis.-.lindsey.jpg|60px]]
         |2={{clade
            |1=[[Taeniopterygidae]] [[File:Taeniopteryx nebulosa2.jpg|60px]]
            |2=[[Scopuridae]]
            |state2=dashed
            }}
         |3=[[Capniidae]] [[File:Capnopsis schilleri.jpg|60px]]
         |4={{clade
            |1=[[Nemouridae]] [[File:Amphinemura albicauda (10.3897-zookeys.808.29433) Figure 1.jpg|60px]]
            |2=[[Notonemouridae]]
            }}
         }}
      |label2=Systellognatha
      |2={{clade
         |1=[[Peltoperlidae]] [[File:Soliperla sierra.jpg|60px]]
         |2=[[Pteronarcyidae]] [[File:Pteronarcyidae a.JPG|60px]]
         |3=[[Styloperlidae]]
         |4={{clade
            |1=[[Perlidae]] [[File:Perlidae P1400217a.jpg|50px]]
            |2={{clade
               |1=[[Chloroperlidae]] [[File:Xanthoperla apicalis 01.JPG|60px]]
               |2=[[Perlodidae]] [[File:Perlodes sp.jpg|60px]]
               }}
            }}
         }}
      }}
   }}
}}

==Notes==
{{Reflist|group=Note}}

==References==
{{Reflist|32em}}

==External links==
* {{Commons category-inline}}
* {{Wikispecies-inline}}
* Plecoptera Species File: [http://plecoptera.speciesfile.org/Common/basic/Taxa.aspx?TaxonNameID=1152749 order Plecoptera (Version 5.0/5.0)]
{{Orders of Insects}}
{{Plecoptera}}
{{Taxonbar|from=Q203547}}
{{Authority control}}

{{DEFAULTSORT:Plecoptera}}
[[Category:Plecoptera| ]]
[[Category:Insect orders]]
[[Category:Extant Permian first appearances]]
[[Category:Taxa named by Hermann Burmeister]]
[[Category:Symbols of Delaware]]
[[Category:Aquatic insects]]
[[Category:Polyneoptera]]