page_title: Dragonfly
section_title: Reproduction
hierarchical_section_title: Dragonfly / Biology / Reproduction
caption_attribution_description: English: Orthetrum luzonicum, Tricolored Marsh Hawk, is a medium sized dragonfly with blue, yellow and brown markings. Eyes are bluish green with violet or brownish spots. Thorax is pale olivaceous green with brown lateral stripes. Dorsal side has a distinct yellow "Y" shaped mark. In older individuals, brown and yellow markings may be totally replaced by pale blue pruinescence. They look alike Orthetrum glaucum and Orthetrum triangulare. However, the eyes of Orthetrum luzonicum are a vivid blue/green colour and of Orthetrum glaucum eyes are dull in comparison. The male's thorax and abdomen are bright powdery blue and S9-10 can be black, though there are specimens where this turns blue too. The males also have slight yellow/black markings on the abdomen, which seem slightly variable depending on age. Like the male, the female becomes pruinosed. The thoracic markings are different and the eyes are similar in colour to that of the male, making it easily identifiable.
context_page_description: A dragonfly is an insect belonging to the order Odonata, infraorder Anisoptera. Adult dragonflies are characterized by large, multifaceted eyes, two pairs of strong, transparent wings, sometimes with coloured patches, and an elongated body. Dragonflies can be mistaken for the related group, damselflies, which are similar in structure, though usually lighter in build; however, the wings of most dragonflies are held flat and away from the body, while damselflies hold the wings folded at rest, along or above the abdomen. Dragonflies are agile fliers, while damselflies have a weaker, fluttery flight. Many dragonflies have brilliant iridescent or metallic colours produced by structural coloration, making them conspicuous in flight. An adult dragonfly's compound eyes have nearly 24,000 ommatidia each.
  Fossils of very large dragonfly ancestors in the Protodonata are found from 325 million years ago in Upper Carboniferous rocks; these had wingspans up to about 750 mm. There are about 3,000 extant species. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threatens dragonfly populations around the world.
context_section_description: 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. 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"; the pair may also be described as being "in cop".
  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. The male attempts to prevent rivals from removing his sperm and inserting their own, something made possible by delayed fertilisation and driven by sexual selection. If successful, a rival male uses his penis to compress or scrape out the sperm inserted previously; this activity takes up much of the time that a copulating pair remains in the heart posture. 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.
  Egg-laying takes two different forms depending on the species. The female in some families 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. 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.
caption: Mating pair of marsh skimmers, Orthetrum luzonicum, forming a "heart"
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