Editing Odonata (section)

=== 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 />