Editing Odonata

{{short description|Order of insects that includes the dragonflies and damselflies}}
{{Automatic taxobox
| oldest_fossil = Late Triassic
| image = Aeshna juncea hovering.jpg
| image_caption = ''Aeshna juncea'' hovering over a pond.
| display_parents = 4
| taxon = Odonata
| authority = [[Johan Christian Fabricius|Fabricius]], 1793
| subdivision_ranks = Suborders
| subdivision = * [[Epiprocta]]
** [[Epiophlebiidae]]
** [[Anisoptera]] (dragonflies)
* [[Zygoptera]] (damselflies)
For extinct groups, see text
}}

'''Odonata''' is an [[order (biology)|order]] of [[predatory]] [[flying insect]]s that includes the [[dragonflies]] and [[damselflies]] (as well as the ''[[Epiophlebia]]'' damsel-dragonflies). The two major groups are distinguished with dragonflies (Anisoptera) usually being bulkier with large [[compound eye]]s together and wings spread up or out at rest, while damselflies (suborder [[Zygoptera]]) are usually more slender with eyes placed apart and wings folded together along body at rest. Adult odonates can land and perch, but rarely walk.

All odonates have [[aquatic animal|aquatic]] [[larva]]e called [[naiad (insect)|naiad]]s or [[nymph (biology)|nymph]]s, and all of them, larvae and adults, are [[carnivorous]] and are almost entirely [[insectivorous]], although at the larval stage they will eat anything that they can overpower, including small [[fish]], [[tadpole]]s, and even adult [[newt]]s. The adults are superb aerial hunters and their legs are specialised for catching prey in flight.

Odonata in its narrow sense forms a subgroup of the broader [[Odonatoptera]], which contains other dragonfly-like insects.
The scientific study of the Odonata is called odonatology.<ref>{{cite web |url=https://www.collinsdictionary.com/dictionary/english/odonatology |title=Odonatology |website=www.collinsdictionary.com |access-date=19 November 2024 |publisher=Collins }}</ref>

== Etymology and terminology==

[[Johan Christian Fabricius]] coined the term ''Odonata'' in 1793 from the [[Ancient Greek]] {{lang|grc|ὀδών}} {{transliteration|grc|odṓn}} ([[Ionic Greek|Ionic]] form of {{lang|grc|ὀδούς}} {{transliteration|grc|odoús}}) "tooth". One hypothesis is that it was because their [[Insect mouthparts|maxillae]] are notably toothed.<ref>{{cite journal |last1=Mickel |first1=Clarence E. |year=1934 |title=The significance of the dragonfly name "Odonata" |journal=Annals of the Entomological Society of America |volume=27 |issue=3 |pages=411–414 |doi=10.1093/aesa/27.3.411}}</ref>

The word ''dragonfly'' usually denotes only [[Anisoptera]], but is sometimes used to mean all Odonata.<ref>{{MerriamWebsterDictionary|odonate}}</ref> Odonata enthusiasts avoid ambiguity by using the term ''true dragonfly'',<ref>{{cite book |title=Field Guide to Lower Aquarium Animals |year=1939 |publisher=Cranbrook Institute of Science}}</ref> or simply ''anisopteran'',<ref>{{cite book |last=Orr |first=A.G. |year=2005 |title=Dragonflies of Peninsular Malaysia and Singapore |isbn=978-983-812-103-3 |publisher=Natural History Publications |place = Borneo }}</ref> when they mean just the Anisoptera. An alternative term ''warriorfly'' has been proposed.<ref>{{cite book |first1=Philip S. |last1=Corbet |first2=Stephen J. |last2=Brook |year=2008 |title=Dragonflies |publisher=Collins |location=London, UK |isbn=978-0-00-715169-1 }}</ref>

== External morphology ==

{{main|External morphology of Odonata}}

=== Size ===

The largest living odonate is the giant [[Central America]]n helicopter damselfly ''[[Megaloprepus coerulatus]]'' (Zygoptera: Pseudostigmatidae) with a wing span of {{Convert|191|mm|in|abbr=on}}. The heaviest living odonates are ''[[Tetracanthagyna plagiata]]'' (Anisoptera: Aeshnidae) with a wing span of {{Convert|165|mm|in|abbr=on}}, and ''[[Petalura ingentissima]]'' (Anisoptera: Petaluridae) with a body length of {{Convert|117|mm|in|abbr=on}} (some sources {{Convert|125|mm|in|abbr=on}}) and wing span of {{Convert|160|mm|in|abbr=on}}. The longest extant odonate is the Neotropical helicopter damselfly ''[[Mecistogaster]] linearis'' (Zygoptera: Pseudostigmatidae) with a body length of {{Convert|135|mm|in|abbr=on}}.<ref name="y573">{{cite journal| last=Wilson | first=Keith D. P. | title=Dragonfly Giants | journal=Agrion| volume=13 | issue=1 | date=2009-01-01 | url=https://www.researchgate.net/publication/274080561 | access-date=2024-06-04 | pages=29–31}}</ref>

The smallest living dragonfly is ''[[Nannophya pygmaea]]'' (Anisoptera: Libellulidae) from east Asia, with a body length of {{Convert|15|mm|in|abbr=on}} and a wing span of {{Convert|20|mm|in|abbr=on}}. The smallest damselflies (and also the smallest odonates) are species of the genus ''[[Agriocnemis]]'' (Zygoptera: Coenagrionidae) with a wing span of only {{Convert|17–18|mm|in|abbr=on}}.<ref name="x473">{{cite journal | last1=Kipping | first1=Jens | last2=Martens | first2=Andreas | last3=Suhling | first3=Frank | title=Africa's smallest damselfly—a new Agriocnemis from Namibia (Odonata: Coenagrionidae) | journal=Organisms Diversity & Evolution | volume=12 | issue=3 | date=2012 | issn=1439-6092 | doi=10.1007/s13127-012-0084-4 | pages=301–306| bibcode=2012ODivE..12..301K }}</ref>

=== Description ===

[[File:Common blue damselfly02.jpg|thumb|left|upright|Male [[blue ringtail]] (''Austrolestes annulosus''),  a damselfly ([[Zygoptera]]: [[Lestidae]])]]

[[File:OdonataWings.jpg|thumb|right|Dragonfly (top) and damselfly (bottom) wing shape and venation]]

These insects characteristically have large rounded heads covered mostly by well-developed, [[compound eye]]s, which provide good vision, legs that facilitate catching prey (other insects) in flight, two pairs of long, transparent wings that move independently, and elongated abdomens. They have three [[ocelli]] and short [[antenna (biology)|antennae]]. The [[insect mouthparts|mouthparts]] are on the underside of the head and include simple chewing [[mandible (arthropod)|mandibles]] in the adult.<ref name=IIBD>{{cite book |author=Hoell, H.V., Doyen, J.T. & Purcell, A.H. |year=1998 |title=Introduction to Insect Biology and Diversity |edition=2nd |publisher=Oxford University Press |isbn=978-0-19-510033-4 |pages=355–358}}</ref>

Flight in the Odonata is [[Insect flight#Direct flight|direct]], with flight muscles attaching directly to the wings; rather than indirect, with flight muscles attaching to the thorax, as is found in the [[Neoptera]]. This allows active control of the amplitude, frequency, angle of attack, camber and twist of each of the four wings entirely independently.<ref>{{cite journal |first1 = Richard J. |last1 = Bomphrey |first2 = Toshiyuki |last2 = Nakata |first3 = Per |last3 = Henningsson |first4 = Huai-Ti |last4 = Lin |year = 2016 |title = Flight of the dragonflies and damselflies |journal = [[Philosophical Transactions of the Royal Society B]] |volume = 371 |issue = 1704 |page = 2015.0389 |doi = 10.1098/rstb.2015.0389 |pmid = 27528779 |pmc = 4992713 }}</ref>

In most families, there is a structure on the leading edge near the tip of the wing called the [[pterostigma]]. This is a thickened, [[hemolymph]]–filled and often colorful area bounded by veins. The functions of the pterostigma are not fully known, but it most probably has an aerodynamic effect and may also have a visual function. More mass at the end of the wing may also reduce the energy needed to move the wings up and down. The right combination of wing stiffness and wing mass could reduce the energy consumption of flying. A pterostigma is also found among other insects, such as bees.<ref>{{cite journal |last=Norberg |first=R. Åke |year=1972 |title=The pterostigma of insect wings an inertial regulator of wing pitch |journal=Journal of Comparative Physiology A |volume=81 |issue=1 |pages=9–22 |doi=10.1007/BF00693547 |s2cid=23441098 }}</ref>

The nymphs have stockier, shorter, bodies than the adults. In addition to lacking wings, their eyes are smaller, their antennae longer, and their heads are less mobile than in the adult. Their mouthparts are modified, with the labium being adapted into a unique prehensile organ called a labial mask for grasping prey.<ref>{{cite journal |first1 = S. |last1 = Büsse |first2 = H.-L. |last2 = Tröger |first3 = S.N. |last3 = Gorb |date = 11 August 2021 |title = The toolkit of a hunter – functional morphology of larval mouthparts in a dragonfly |volume = 315 |issue = 4 |pages = 247–260 |journal = [[Journal of Zoology]] |doi = 10.1111/jzo.12923 |doi-access = free }}</ref> Damselfly [[Nymph (biology)|nymph]]s breathe through external [[gill]]s on the abdomen, while dragonfly nymphs respire through an organ in their [[rectum]].<ref name=IIBD />

== Evolution ==

=== Fossil history ===

[[File:Meganeura monyi au Museum de Toulouse.jpg|thumb|The giant [[Upper Carboniferous]] dragonfly ancestor, ''[[Meganeura]] monyi'', had a wingspan of about {{convert|680|mm|in|abbr=on}},<ref>{{cite book |title=The Biology of Dragonflies |url=https://books.google.com/books?id=J584AAAAIAAJ&pg=PA324 |publisher=Cambridge University Press Archive |date=2018 |page=324 |id=GGKEY:0Z7A1R071DD |quote=No Dragonfly at present existing can compare with the immense ''[[Meganeura monyi]]'' of the [[Upper Carboniferous]], whose expanse of wing was somewhere about twenty-seven inches.}}</ref>]]

Members of the [[crown group]] Odonata first appeared during the [[Late Triassic]],<ref name=palaeo-electronica>{{cite journal |last1=Kohli |first1=Manpreet Kaur |last2=Ware |first2=Jessica L. |last3=Bechly |first3=Günter |year=2016 |title=How to date a dragonfly: Fossil calibrations for odonates |journal=Palaeontologia Electronica |volume=19 |issue=1 |page=576 |doi=10.26879/576 |doi-access=free |url=http://palaeo-electronica.org/content/fc-8 }}</ref> though members of their [[Crown group|total group]], [[Odonatoptera]], first appeared in the [[Late Carboniferous]], making them one of the earliest groups of winged insects.<ref name=palaeo-electronica/> The fossils of odonates and their cousins, including [[Paleozoic]] "giant dragonflies" like ''[[Meganeuropsis]] permiana'' from the [[Permian]] of North America, reached wing spans of up to {{convert|71|cm|in|abbr=on}} and a body length of {{convert|43|cm|in|abbr=on}}, making it the largest insect of all time.<ref>{{cite book |last1=Mitchell |first1=F.L. |last2=Lasswell |first2=J. |year=2005 |title=A Dazzle of Dragonflies |publisher=Texas A&M University Press |page=47}}</ref> This insect belonged to the order [[Meganisoptera]], the griffinflies, related to odonates but not part of the modern order Odonata in the restricted sense. They have one of the most complete fossil records going back 319 million years.<ref name=Bybee-CórdbAglr-etal-2016>{{Cite journal |last1=Bybee |first1=Seth |last2=Córdoba-Aguilar |first2=Alex |last3=Duryea |first3=M. Catherine |last4=Futahashi |first4=Ryo |last5=Hansson |first5=Bengt |last6=Lorenzo-Carballa |first6=M. Olalla |last7=Schilder |first7=Ruud |last8=Stoks |first8=Robby |last9=Suvorov |first9=Anton |display-authors=3 |date=December 2016 |title=Odonata (dragonflies and damselflies) as a bridge between ecology and evolutionary genomics |journal=Frontiers in Zoology |volume=13 |issue=1 |page=46 |doi=10.1186/s12983-016-0176-7 |doi-access=free |issn=1742-9994 |pmc=5057408 |pmid=27766110 }}</ref>

The Odonata is closely related to [[mayflies]] and several extinct orders in a group called the [[Palaeoptera]], but this grouping might be [[paraphyletic]]. What they do share with mayflies is the nature of [[insect flight|how the wings are articulated and held in rest]].<ref name="k975">{{cite journal | last1=Ninomiya | first1=Tomoya | last2=Yoshizawa | first2=Kazunori | title=A revised interpretation of the wing base structure in Odonata | journal=Systematic Entomology | volume=34 | issue=2 | date=2009 | issn=0307-6970 | doi=10.1111/j.1365-3113.2008.00455.x | pages=334–345| bibcode=2009SysEn..34..334N | hdl=2115/42988 | hdl-access=free }}</ref>

[[Tarsophlebiidae]] is a prehistoric family of Odonatoptera that can be considered either a basal lineage of Odonata or their immediate [[sister taxon]].<ref name="x206">{{cite journal| last1=Fleck | first1=G. | last2=Bechly | first2=G. | last3=Martinez-Delclòs | first3=X. | last4=Jarzembowski | first4=E.A. | last5=Nel | first5=A. | title= A revision of the Mesozoic dragonfly family Tarsophlebiidae, with a discussion on the phylogenetic positions of the Tarsophlebiidae and Sieblosiidae (Odonatoptera: Panodonata). | journal=Geodiversitas | date=2004-06-01 | url=https://www.researchgate.net/publication/278817520 | access-date=2024-06-04}}</ref>

=== Phylogeny ===

The phylogenetic tree of the orders and suborders of odonates according to Bybee et al. 2021:<ref name="Bybee 2021">{{cite journal | last1=Bybee | first1=Seth M. | last2=Kalkman | first2=Vincent J. | last3=Erickson | first3=Robert J. | last4=Frandsen | first4=Paul B. | last5=Breinholt | first5=Jesse W. | last6=Suvorov | first6=Anton | last7=Dijkstra | first7=Klaas-Douwe B. | last8=Cordero-Rivera | first8=Adolfo | last9=Skevington | first9=Jeffrey H. | last10=Abbott | first10=John C. | last11=Sanchez Herrera | first11=Melissa | last12=Lemmon | first12=Alan R. | last13=Moriarty Lemmon | first13=Emily | last14=Ware | first14=Jessica L. |display-authors=3 | title=Phylogeny and classification of Odonata using targeted genomics | journal=Molecular Phylogenetics and Evolution | publisher=Elsevier BV | volume=160 | year=2021 | issn=1055-7903 | doi=10.1016/j.ympev.2021.107115 | page=107115| pmid=33609713 | doi-access=free | bibcode=2021MolPE.16007115B | hdl=11093/2768 | hdl-access=free }}</ref>

{{clade
|style=font-size:100%;line-height:110%
|label1 =Odonata
|1={{clade
   |label1 =
   |1={{clade
   |label1 =
      |1 =[[Zygoptera]] (damselflies) [[File:Megaloprepus coerulatus Drury.png|100px]]
      |2={{clade
         |label1 =[[Epiprocta]]
         |1={{clade
            |label1 =
            |1={{clade
               |label1 =
               |1 =[[Anisozygoptera]]  [[File:Epiophlebia_superstes_f.png|70px]]
               |2 =[[Anisoptera]] (dragonflies) [[File:Illustrations of Exotic Entomology II 47 ('LIBELLULA AXILENA').jpg|100px]]
               }}
            }}
         }}
      }}
   }}
}}

=== Taxonomy ===
In some treatments,{{sfnp|Trueman|Rowe|2008}} the Odonata are understood in an expanded sense, essentially synonymous with the [[superorder]] [[Odonatoptera]], but not including the prehistoric [[Protodonata]]. In this approach, instead of Odonatoptera, the term Odonatoidea is used. The [[systematics]] of the "Palaeoptera" are by no means resolved; what can be said however is that regardless of whether they are called "Odonatoidea" or "Odonatoptera", the Odonata and their extinct relatives do form a [[clade]].{{sfnp|Trueman|2008}}

The [[Anisoptera]] was long treated as a suborder, with a third suborder, the Anisozygoptera (ancient dragonflies). However, the combined suborder [[Epiprocta]] (in which Anisoptera is an infraorder) was proposed when it was thought that the "Anisozygoptera" was paraphyletic, composed of mostly extinct offshoots of dragonfly evolution. The four living [[species]] placed in that group are (in this treatment) in the infraorder [[Epiophlebioptera]], whereas the fossil [[taxa]] that were formerly there are now dispersed about the Odonatoptera (or Odonata ''[[sensu lato]]'').{{sfnp|Lohmann|1996}}{{sfnp|Rehn|2003}} World Odonata List considers [[Anisoptera]] as a suborder along with [[Zygoptera]] and [[Anisozygoptera]] as well-understood and widely preferred terms.<ref>{{World Odonata List}}</ref><ref name=Bybee-Kalkman-etal-2021>{{cite journal |last1=Bybee |first1=Seth M. |last2=Kalkman |first2=Vincent J. |last3=Erickson |first3=Robert J. |last4=Frandsen |first4=Paul B. |last5=Breinholt |first5=Jesse W. |last6=Suvorov |first6=Anton |last7=Dijkstra |first7=Klaas-Douwe B. |last8=Cordero-Rivera | first8=Adolfo |last9=Skevington |first9=Jeffrey H. |last10=Abbott |first10=John C. |last11=Sanchez Herrera | first11=Melissa |last12=Lemmon |first12=Alan R. |last13=Moriarty Lemmon | first13=Emily |last14=Ware |first14=Jessica L. |display-authors=6 |year=2021a |title=Phylogeny and classification of Odonata using targeted genomics |journal=Molecular Phylogenetics and Evolution |volume=160 |page=107115 |issn=1055-7903 |doi=10.1016/j.ympev.2021.107115 |doi-access=free |pmid=33609713 |bibcode=2021MolPE.16007115B |hdl=11093/2768 | hdl-access=free }}</ref>

Cladogram of Epiprocta after Rehn et al. 2003{{sfnp|Rehn|2003|pages=181–240}}:{{clade|{{clade
|1=[[Zygoptera]] (damselflies)
|label2='''Epiprocta'''
|2={{clade
|1=[[Epiophlebioptera]]
|2={{clade
|1={{extinct}}[[Isophlebioptera]]
|2={{clade
|1={{extinct}}[[Heterophlebioptera]]
|2={{clade
|1={{extinct}}[[Stenophlebioptera]]
|2={{clade
|1={{extinct}}[[Aeschnidioptera]]
|2=[[Anisoptera]] (dragonflies)
}}}}}}}}}}}}|label1=Odonata}}Cladogram of [[Odonatoptera]] including Odonata by Deregnaucourt et al. 2023.<ref>{{Cite journal |last1=Deregnaucourt |first1=Isabelle |last2=Bardin |first2=Jérémie |last3=Villier |first3=Loïc |last4=Julliard |first4=Romain |last5=Béthoux |first5=Olivier |date=August 2023 |title=Disparification and extinction trade-offs shaped the evolution of Permian to Jurassic Odonata |journal=iScience |language=en |volume=26 |issue=8 |pages=107420 |doi=10.1016/j.isci.2023.107420 |pmc=10424082 |pmid=37583549}}</ref>

{{clade|{{clade
 |label1=†[[Meganisoptera]]
 |1=†[[Meganeuridae]]
 |label2=[[Nodialata]]
 |2={{clade
  |label1=†[[Protanisoptera]]
  |1={{clade
   |1=†[[Polytaxineuridae]]
   |2={{clade
    |1=†[[Permaeschnidae]]
    |2={{clade
     |1=†[[Callimokaltaniidae]]
     |2={{clade
      |1=†[[Hemizygopteridae]]
      |2=†[[Ditaxineuridae]] }} }} }} }}
  |label2=[[Discoidalia]]
  |2={{clade
   |label1=†[[Triadophlebiomorpha]]
   |1={{clade
    |1=†''[[Iverya]]''
    |2={{clade
     |1=†[[Pirouteliidae]]
     |2={{clade
      |1=†[[Kargalotypidae]]
      |label2=†[[Zygophlebiida]]
      |2={{clade
       |1=†[[Zygophlebiidae]]
       |2=†[[Moltenophlebiidae]]
       |3={{clade
        |1=†[[Permophlebiidae]]
        |2=†[[Xamenophlebiidae]] }} }}
      |label3=†[[Triadophlebiida]]
      |3={{clade
       |1=†[[Triassologus]]
       |2=†[[Sinotriadophlebiidae]]
       |3=†[[Mitophlebiidae]]
       |4={{clade
        |1=†[[Paurophlebiidae]]
        |2=†[[Triadophlebiidae]] }} }} }} }} }}
   |label2=[[Stigmoptera]]
   |2={{clade
    |1=†[[Permagrionidae]]
    |2={{clade
     |label1=†[[Archizygoptera]]
     |1={{clade
      |1=†[[Bakteniidae]]
      |2=†[[Kennedyidae]]
      |3=†[[Oboraneuridae]]
      |4=†[[Kaltanoneuridae]]
      |5=†[[Lodeviidae]]
      |6=†[[Luiseiidae]]
      |7=†[[Permepallagidae]]
      |8={{clade
       |1=†[[Voltzialestidae]]
       |label2=†[[Terskejoptera]]
       |2={{clade
        |1=†''[[Terskeja]]''
        |2={{clade
         |1=†[[Protomyrmeleontidae]]
         |2=†[[Moltenagrionidae]] }} }} }} }}
     |label2=[[Panodonata]]
     |2={{clade
      |1=†[[Triassolestidae]] (in part)
      |label2=[[Lobodonata]]
      |2={{clade
       |1=†[[Mesophlebiidae]]
       |2=†[[Triassolestidae]] (in part)
       |3={{clade
        |1=†[[Tarsophlebiidae]]
|label2='''Odonata''' crown group
        |2={{clade
         |1=[[Zygoptera]] (damselflies)
         |label2=[[Epiproctophora]]
         |2={{clade
          |1={{clade
           |1=†[[Euthemistidae]]
           |2=†[[Selenothemistidae]]
           |3={{clade
            |1=†[[Archithemistidae]]
            |2={{clade
             |1=†[[Campterophlebiidae]]
             |2=†[[Isophlebiidae]] }} }}
           |4={{clade
            |1=†[[Sphenophlebiidae]]
            |2={{clade
             |1=†[[Asiopteridae]]
             |2=†[[Cyclothemistidae]] }} }} }}
          |2={{clade
           |1=†[[Erichschmidtiidae]]
           |2={{clade
            |1=†[[Liassostenophlebiidae]]
            |2={{clade
             |1=†[[Prostenophlebiidae]]
             |2=†[[Stenophlebiidae]] }} }}
           |3={{clade
            |1=†[[Myopophlebiidae]]
            |2={{clade
             |1=†[[Heterophlebiidae]]
             |2={{clade
              |1=†[[Liassophlebiidae]]
              |2=†[[Parastenophlebiidae]] }} }} }}
           |4={{clade
            |1=†[[Juragomphidae]]
            |2=†[[Liassogomphidae]]
            |3={{clade
             |1=†[[Aeschnidiidae]]
             |2=[[Anisoptera]] (modern dragonflies) }} }} }} }} }} }} }} }} }} }} }} }} }}|style=font-size:85%; line-height:85%;|label1=[[Odonatoptera]] (Odonata ''sensu lato'')}}

== Ecology and life cycle ==
[[File:070526 142326 Libellen cr.jpg|thumb|Ovipositing flight of two pairs of azure damselflies (''[[Coenagrion puella]]'') ]]

Odonates are aquatic or semi-aquatic as juveniles. Thus, adults are most often seen near bodies of water and are frequently described as aquatic insects. However, many species range far from water. They are [[carnivorous]] (or more specifically [[insectivorous]]) throughout their life, mostly feeding on smaller insects.<ref>{{cite journal |last1=May |first1=ML |title=Odonata: Who They Are and What They Have Done for Us Lately: Classification and Ecosystem Services of Dragonflies. |journal=Insects |date=28 February 2019 |volume=10 |issue=3 |page=62 |doi=10.3390/insects10030062 |doi-access=free |pmid=30823469 |pmc=6468591 }}</ref>

Male Odonata have complex genitalia, different from those found in other insects. These include grasping [[Cercus|cerci]]  at the tip of the abdomen for holding the female, and a secondary set of copulatory organs located between the second and third abdominal segment in which the [[spermatozoa]] are stored after being produced by the primary genitals— whose external opening is known as the genital pore, on the ninth abdominal segment. This process is called intra-male sperm translocation (ST).<ref>{{cite journal |first1 = Jagbir S. |last1 = Kirti |first2 = Archana |last2 = Singh |date = June 2004 |title = Studies on the secondary male Genitalia of the type species of some dragonflies (Odonata: Anisoptera: Libellulidae) |department = Case report |journal = Zoos' Print Journal |volume = 19 |issue = 6 |pages = 1505–1511 |doi = 10.11609/JoTT.ZPJ.984.1505-11 |url = https://www.zoosprint.zooreach.org/index.php/zpj/article/view/6295/5712 |url-status = dead |access-date = 2024-05-06 |archive-url = https://web.archive.org/web/20240228041645/https://zoosprint.zooreach.org/index.php/zpj/article/download/6295/5712 |archive-date = 2024-02-28}}</ref><ref>{{cite report |title = Evolution and diversity of intra-male sperm translocation in Odonata: A unique behaviour in animals |year = 2019 |website = agris.fao.org |publisher = [[United Nations]] |series = U.N. [[Food and Agriculture Organization]] |url = https://agris.fao.org/agris-search/search.do?recordID=US201900218669 }}</ref> Because the male copulatory organ has evolved independently from that in other insects, it has been suggested the stem-group dragonflies had external sperm transfer.<ref>{{cite journal |first1 = Rolf G. |last1 = Beutel |first2 = Margarita I. |last2 = Yavorskaya |first3 = Yuta |last3 = Mashimo |first4 = Makiko |last4 = Fukui |first5 = Karen |last5 = Meusemann |year = 2017 |title = The phylogeny of Hexapoda (Arthropoda) and the evolution of megadiversity |journal = Proceedings of the Arthropod and Embryological Society of Japan |volume = 51 |pages =  1–15 |issn = 1341-1527 |url = http://aesj.co-site.jp/Vol51/2017_Vol.51_1.pdf }}</ref> To mate, the male claspers grasps the female by the thorax (Zygoptera) or head (Anisoptera) while the female bends her abdomen so that her own genitalia can be grasped by the copulatory organ holding the sperm. This is known as the "wheel" position.<ref name=IIBD/> In Anisoptera, males often mate while flying, lifting the females in the air, which typically last from a couple of seconds to a minute or two, whereas the males in Zygoptera mate while perched. They might even move to different spots during the mating process, which can make it last longer, anywhere between five and ten minutes. Male Odonata are very competitive when it comes to mating that in some species, the males use the [[Cercus|cerci]] located at the tip of the abdomen to remove the sperm of a rival male's from the female and put in his own.<ref>{{Cite web |title=Mating and Reproduction in Odonata |url=https://www.brisbaneinsects.com/brisbane_dragons/Mating.htm |access-date=2024-10-02 |website=www.brisbaneinsects.com}}</ref><ref>{{Cite web |title=Odonata: Dragonflies and Damselflies |url=https://ucmp.berkeley.edu/arthropoda/uniramia/odonatoida.html |access-date=2024-10-02 |website=ucmp.berkeley.edu}}</ref>

Eggs are laid in water or on vegetation near water or wet places, and hatch to produce pronymphs which live off the nutrients that were in the egg. They then develop into [[instar]]s with approximately 9–14 [[Moult|molts]] that are (in most species) voracious [[predator]]s on other aquatic organisms, including small [[fish]]es. The [[Nymph (biology)|nymphs]] grow and molt, usually in dusk or dawn, into the flying teneral immature adults, whose color is not yet developed. These transform into reproductive adults.{{citation needed|date=September 2023}}

Odonates can act as [[bioindicators]] of water quality in [[river]]s because they rely on high quality water for proper development in early life. Since their diet consists entirely of insects, odonate density is directly proportional to the population of prey, and their abundance indicates the abundance of prey in the examined [[ecosystem]].<ref>{{cite journal |last1=Golfieri |first1=Bruno |last2=Hardersen |first2=Sönke |last3=Maiolini |first3=Bruno |last4=Surian |first4=Nicola |title=Odonates as indicators of the ecological integrity of the river corridor: Development and application of the Odonate River Index (ORI) in northern Italy |journal=Ecological Indicators |volume=61 |year=2016 |issn=1470-160X |doi=10.1016/j.ecolind.2015.09.022 |pages=234–247|bibcode=2016EcInd..61..234G }}</ref> [[Species richness]] of vascular plants has also been positively correlated with the species richness of dragonflies in a given habitat. This means that in a location such as a lake, if one finds a wide variety of odonates, then a similarly wide variety of plants should also be present. This correlation is not common to all bioindicators, as some may act as indicators for a different environmental factor, such as the [[pool frog]] acting as a bioindicator of water quality due to its high quantity of time spent in and around water.<ref>{{cite journal |last1=Sahlén |first1=Göran |last2=Ekestubbe |first2=Katarina |title=Identification of dragonflies (Odonata) as indicators of general species richness in boreal forest lakes |journal=[[Biodiversity and Conservation]] |date=16 May 2000 |volume=10 |issue=5 |pages=673–690 |doi=10.1023/A:1016681524097 |s2cid=40735036}}</ref>

In addition, odonates are very sensitive to changes to average temperature. Many species have moved to higher elevations and latitudes as global temperature rises and habitats dry out. Changes to the life cycle have been recorded with increased development of the instar stages and smaller adult body size as the average temperature increases. As the territory of many species starts to overlap, the rate hybridization of species that normally do not come in contact is increasing. If global climate change continues many members of Odonata will start to disappear. Because odonates are such an old order and have such a complete fossil record they are an ideal species to study insect evolution and adaptation. For example, they are one of the first insects to develop flight and it is likely that this trait only evolved once in insects, looking at how flight works in odonates, the rest of flight can be mapped out.<ref name=Bybee-CórdbAglr-etal-2016/>

=== Cannibalism ===
[[Cannibalism]] has been recorded in many species of odonates, at both the larval and adult stages. Cannibalism is caused by either errors in species recognition, intrasexual competition for mating, or prevention of mating harassment.<ref>{{Citation |last=Payra |first=Arajush |title=Cannibalism in adult odonates (dragonflies and damselflies): an intriguing but unexplored behavior |date=2024-08-23 |url=https://www.authorea.com/users/817151/articles/1217677-cannibalism-in-adult-odonates-dragonflies-and-damselflies-an-intriguing-but-unexplored-behavior?commit=ef438aa11da1b0cc93b4832b790ffbc2ee4431e3 |access-date=2024-12-10 |doi=10.22541/au.172444978.81732780/v1 |last2=Khan |first2=Kawsar |last3=Koparde |first3=Pankaj}}</ref><gallery mode="packed" heights="160" caption="Cannibalism in odonates">
File:Eastern Pondhawk imported from iNaturalist photo 17394744 on 2 December 2024 (cropped).jpg|Female [[Erythemis simplicicollis|eastern pondhawk]] eating a young male
File:Slender Skimmer, Jatinangor, Sumedang Regency, West Java, Indonesia imported from iNaturalist photo 352693004.jpg|[[Orthetrum sabina|Slender skimmer]]
File:Small Red Damselfly, 86210 Vouneuil-sur-Vienne, France imported from iNaturalist photo 137623526.jpg|[[Small red damselfly]]
File:Orange-tailed Marsh Dart, Kaoh Kong, Kaôh Kong, Cambodia imported from iNaturalist photo 75689717.jpg|[[Ceriagrion cerinorubellum|Orange-tailed marsh dart]]
</gallery>

== Gallery ==

<gallery mode=packed widths=150px heights=150px>
File:Ceriagrion cerinorubellum-Kadavoor-2016-04-11-002 (cropped).jpg|A pair of ''[[Ceriagrion cerinorubellum]]'' mating
File:Small pincertail (Onychogomphus forcipatus) male Bulgaria (cropped).jpg|''[[Onychogomphus forcipatus]]'' male
File:Libellula depressa.jpg|''[[Libellula depressa]]'' resting
File:Odonata nymph 1 (6016609118).png|Nymph
File:Anax imperator 2015 11 23 6807 (cropped).jpg|[[Emperor (dragonfly)|''Anax imperator'']] in flight
</gallery>

== See also ==
Various lists of Odonata species of different regions:
{{div col begin|colwidth=10em}}
* [[List of Odonata species of Australia|Australia]]
* [[List of Odonata species of Great Britain|Britain]]
* [[List of Canadian dragonflies|Canadian dragonflies]]
* [[List of Canadian damselflies|Canadian damselflies]] 
* [[List of Odonata species of Estonia|Estonia]]
* [[List of Odonata species of Finland|Finland]]
* [[List of Odonata species of Metropolitan France|France]]
* [[List of odonates of India|India]]
* [[List of Odonata species of Ireland|Ireland]]
* [[List of Odonata species of Slovenia|Slovenia]]
* [[List of Odonata species of South Africa|South Africa]]
* [[List of odonates of Sri Lanka|Sri Lanka]]
* [[List of Odonata species of Taiwan|Taiwan]]
{{div col end}}

== References ==
{{reflist|25em}}

== Cited sources ==
* {{cite journal | last1 = Lohmann | first1 = H. | year = 1996 | title = Das phylogenetische System der Anisoptera (Odonata) | url = | journal = [[Deutsche Entomologische Zeitschrift]] | volume = 106 | issue = 9| pages = 209–266 }}
* {{cite journal|last=Rehn|first= A.|year=2003|title= Phylogenetic analysis of higher-level relationships of Odonata.|journal= Systematic Entomology |volume=28|issue=2|pages= 181–240|doi= 10.1046/j.1365-3113.2003.00210.x|bibcode= 2003SysEn..28..181R}}
* {{cite web|last=Trueman|first=John W. H.|year=2008|website=[[Tree of Life Web Project]]|url=http://www.tolweb.org/accessory/Pterygote_Higher_Relationships?acc_id=450|title=Pterygote Higher Relationships|access-date=15 December 2008}}
* {{cite web|last1=Trueman|first=John W. H.|last2=Rowe|first2=Richard J.|date=20 March 2008|website=[[Tree of Life Web Project]]|url=http://tolweb.org/Odonata/8266/2008.03.20|title=Odonata. Dragonflies and damselflies|access-date=15 December 2008}}

== External links ==

{{Commons category|Odonata}}

{{Wikispecies|Odonata}}
{{Wikibooks|Dichotomous Key|Odonata}}

* {{cite web |title = Anatomy of Odonata |series = Aquatic invertebrates |website = sunsite.ualberta.ca |publisher = [[University of Alberta]]  |url = http://sunsite.ualberta.ca/Projects/Aquatic_Invertebrates/?Page=37 |url-status = dead <!-- presumed -->  |archive-url = https://web.archive.org/web/20080917033039/http://sunsite.ualberta.ca/Projects/Aquatic_Invertebrates/?Page=37 |archive-date = 2008-09-17}}
* {{cite web |title = Dragonflies and damselflies |publisher = [[University of Florida]] |series = [[Institute of Food and Agricultural Sciences|IFAS]] |website = Featured Creatures |url = http://entomology.ifas.ufl.edu/creatures/misc/odonata/odonata.htm}}
* {{cite web |title = Dragonflies and Damselflies (Odonata) of the United States |publisher = [[U.S. Geological Survey]] |website = npwrc.usgs.gov |url = http://www.npwrc.usgs.gov/resource/distr/insects/dfly/dflyusa.htm |url-status = dead <!-- presumed --> |archive-url = https://web.archive.org/web/20060813080200/http://www.npwrc.usgs.gov/resource/distr/insects/dfly/dflyusa.htm |archive-date = 2006-08-13 }} — U.S. state-by-state listing with distribution maps, images
* {{cite web |title = International Journal of Odonatology |url = https://www.tandfonline.com/loi/TIJO20 }}
* {{cite web |title = IORI species list, photos, and social media links |website = iodonata.net |url = http://www.iodonata.net/ |url-status = dead <!-- presumed --> |archive-url=https://web.archive.org/web/20070529185130/http://www.iodonata.net/ |archive-date=2007-05-29 }}
* {{cite web |title = Journal of the Entomological Research Society |type = main page |url = http://www.entomol.org/journal/index.php?journal=JERS}}
* {{cite web |title = Odonata Central |website = odonatacentral.org |type = main page |url = https://odonatacentral.org }}
* {{cite web |title = Odonatologica |website = odonatologica.com |type = main page |url = http://www.odonatologica.com/ }}
* {{World Odonata List}}
* {{cite web |url = https://worlddragonfly.org |title = Worldwide Dragonfly Association }}

{{Odonata}}
{{Orders of Insects}}

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{{DEFAULTSORT:Odonata}}
[[Category:Odonata| ]]
[[Category:Insect orders]]
[[Category:Articles containing video clips]]
[[Category:Insects used as insect pest control agents]]
[[Category:Triassic insects]]
[[Category:Extant Late Triassic first appearances]]
[[Category:Taxa named by Johan Christian Fabricius]]
[[Category:Aquatic insects]]
[[Category:Odonatoptera]]