Editing Dragonfly (section)

=== Reproduction ===

[[File:Orthetrum luzonicum mating of Kadavoor.jpg|thumb|upright|Mating pair of marsh skimmers, ''[[Orthetrum luzonicum]]'', forming a "heart"]]
[[File:Dragonflies on pond.webm|thumb|thumbtime=148|right|Dragonflies over a pond (including female inserting eggs below the water surface.]]

Mating in dragonflies is a complex, precisely choreographed process. First, the male has to attract a female to his territory, continually driving off rival males. When he is ready to mate, he transfers a packet of sperm from his primary genital opening on segment 9, near the end of his abdomen, to his secondary genitalia on segments 2–3, near the base of his abdomen. The male then grasps the female by the head with the claspers at the end of his abdomen; the structure of the claspers varies between species, and may help to prevent interspecific mating.<ref name=Cordero>{{cite book |last1=Cordero-Rivera |first1=Adolfo |last2=Cordoba-Aguilar |first2=Alex |title=15. Selective Forces Propelling Genitalic Evolution in Odonata |year=2010 |page=343 |url=http://ecoevo.uvigo.es/pdf/2010/2010-Genital%20evolution%20odonata-lq.pdf}}</ref> The pair flies in tandem with the male in front, typically perching on a twig or plant stem. The female then curls her abdomen downwards and forwards under her body to pick up the sperm from the male's secondary genitalia, while the male uses his "tail" claspers to grip the female behind the head: this distinctive posture is called the "heart" or "wheel";{{sfn|Dijkstra|2006|pages=8–9}}{{sfn|Trueman|Rowe|2009|page=Life Cycle and Behavior}} the pair may also be described as being "in cop".<ref>{{harvnb|Berger|2004|p=39}}: "Romantic souls are pleased to note that at the climactic moment, the two slender bodies form a delicate heart shape. Experts say the pair is now 'in cop'."</ref>

Egg-laying (ovipositing) involves not only the female darting over floating or waterside vegetation to deposit eggs on a suitable substrate, but also the male hovering above her or continuing to clasp her and flying in tandem. This behaviour following the transfer of sperm is termed as mate guarding and the guarding male attempts to increase the probability of his sperm fertilising eggs. [[Sexual selection]] with sperm competition occurs within the spermatheca of the female and sperm can remain viable for at least 12 days in some species.<ref>{{Cite journal |last=Reinhardt |first=Klaus |date=2005 |title=Sperm numbers, sperm storage duration and fertility limitation in the Odonata |url=https://worlddragonfly.org/article/13887890-2005-9748242/ |journal=International Journal of Odonatology |volume=8 |issue=1 |pages=45–58 |doi=10.1080/13887890.2005.9748242 |issn=1388-7890 |doi-access=free |bibcode=2005IJOdo...8...45R }}</ref><ref name=Carde>{{cite book |author1=Cardé, Ring T. |author2= Resh, Vincent H. |title=A World of Insects: The Harvard University Press Reader |url=https://books.google.com/books?id=g28jXs3CVC8C&pg=PA195 |year=2012 |publisher=[[Harvard University Press]] |isbn=978-0-674-04619-1 |pages=195–197}}</ref> Females can fertilise their eggs using sperm from the spermatheca at any time.{{sfn|Dijkstra|2006|pages=8–9}}{{sfn|Trueman|Rowe|2009|page=Life Cycle and Behavior}}<ref name=Cordero/>  Males use their penis and associated genital structures to compress or scrape out sperm from previous matings; this activity takes up much of the time that a copulating pair remains in the heart posture.{{sfn|Berger|2004|p=39}} Flying in tandem has the advantage that less effort is needed by the female for flight and more can be expended on egg-laying, and when the female submerges to deposit eggs, the male may help to pull her out of the water.<ref name=Carde/>

Egg-laying takes two different forms depending on the species. The female in some families (Aeshnidae, Petaluridae) has a sharp-edged ovipositor with which she slits open a stem or leaf of a plant on or near the water, so she can push her eggs inside. In other families such as clubtails (Gomphidae), cruisers (Macromiidae), emeralds (Corduliidae), and skimmers (Libellulidae), the female lays eggs by tapping the surface of the water repeatedly with her abdomen, by shaking the eggs out of her abdomen as she flies along, or by placing the eggs on vegetation.{{sfn|Berger|2004|p=39}} In a few species, the eggs are laid on emergent plants above the water, and development is delayed until these have withered and become immersed.<ref name=Lawlor>{{cite book |last=Lawlor |first=Elizabeth P. |title=Discover Nature in Water & Wetlands: Things to Know and Things to Do |url=https://books.google.com/books?id=Xo83huW7O6YC&pg=PA94 |year=1999 |publisher=Stackpole Books |isbn=978-0-8117-2731-0 |pages=88, 94–96}}</ref>