Odonata Temporal range: | |
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Aeshna juncea hovering over a pond. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
(unranked): | Dicondylia |
Subclass: | Pterygota |
Division: | Palaeoptera |
Superorder: | Odonatoptera |
Order: | Odonata Fabricius, 1793 |
Suborders | |
For extinct groups, see text |
Odonata is an order of predatory flying insects 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 eyes 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 larvae called naiads or nymphs, 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, tadpoles, and even adult newts. 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. [1]
Johan Christian Fabricius coined the term Odonata in 1793 from the Ancient Greek ὀδώνodṓn (Ionic form of ὀδούςodoús) "tooth". One hypothesis is that it was because their maxillae are notably toothed. [2]
The word dragonfly usually denotes only Anisoptera, but is sometimes used to mean all Odonata. [3] Odonata enthusiasts avoid ambiguity by using the term true dragonfly, [4] or simply anisopteran, [5] when they mean just the Anisoptera. An alternative term warriorfly has been proposed. [6]
The largest living odonate is the giant Central American helicopter damselfly Megaloprepus coerulatus (Zygoptera: Pseudostigmatidae) with a wing span of 191 mm (7.5 in). The heaviest living odonates are Tetracanthagyna plagiata (Anisoptera: Aeshnidae) with a wing span of 165 mm (6.5 in), and Petalura ingentissima (Anisoptera: Petaluridae) with a body length of 117 mm (4.6 in) (some sources 125 mm (4.9 in)) and wing span of 160 mm (6.3 in). The longest extant odonate is the Neotropical helicopter damselfly Mecistogaster linearis (Zygoptera: Pseudostigmatidae) with a body length of 135 mm (5.3 in). [7]
The smallest living dragonfly is Nannophya pygmaea (Anisoptera: Libellulidae) from east Asia, with a body length of 15 mm (0.59 in) and a wing span of 20 mm (0.79 in). The smallest damselflies (and also the smallest odonates) are species of the genus Agriocnemis (Zygoptera: Coenagrionidae) with a wing span of only 17–18 mm (0.67–0.71 in). [8]
These insects characteristically have large rounded heads covered mostly by well-developed, compound eyes, 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 antennae. The mouthparts are on the underside of the head and include simple chewing mandibles in the adult. [9]
Flight in the Odonata is 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. [10]
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. [11]
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. [12] Damselfly nymphs breathe through external gills on the abdomen, while dragonfly nymphs respire through an organ in their rectum. [9]
Members of the crown group Odonata first appeared during the Late Triassic, [14] though members of their total group, Odonatoptera, first appeared in the Late Carboniferous, making them one of the earliest groups of winged insects. [14] 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 71 cm (28 in) and a body length of 43 cm (17 in), making it the largest insect of all time. [15] 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. [16]
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 how the wings are articulated and held in rest. [17]
Tarsophlebiidae is a prehistoric family of Odonatoptera that can be considered either a basal lineage of Odonata or their immediate sister taxon. [18]
The phylogenetic tree of the orders and suborders of odonates according to Bybee et al. 2021: [19]
Odonata |
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In some treatments, [20] 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. [21]
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 ). [22] [23] World Odonata List considers Anisoptera as a suborder along with Zygoptera and Anisozygoptera as well-understood and widely preferred terms. [24] [25]
Cladogram of Epiprocta after Rehn et al. 2003 [26] :
Odonata |
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Cladogram of Odonatoptera including Odonata by Deregnaucourt et al. 2023. [27]
Odonatoptera (Odonata sensu lato) |
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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. [28]
Male Odonata have complex genitalia, different from those found in other insects. These include grasping 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). [29] [30] 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. [31] 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. [9] 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 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. [32] [33]
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 instars with approximately 9–14 molts that are (in most species) voracious predators on other aquatic organisms, including small fishes. The 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 ]
Odonates can act as bioindicators of water quality in rivers 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. [34] 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. [35]
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. [16]
Various lists of Odonata species of different regions:
A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threatens dragonfly populations around the world. Adult dragonflies are characterised by a pair of large, multifaceted, compound eyes, two pairs of strong, transparent wings, sometimes with coloured patches, and an elongated body. 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.
Damselflies are flying insects of the suborder Zygoptera in the order Odonata. They are similar to dragonflies but are usually smaller and have slimmer bodies. Most species fold the wings along the body when at rest, unlike dragonflies which hold the wings flat and away from the body. Damselflies have existed since the Late Jurassic, and are found on every continent except Antarctica.
Calopterygidae is a family of damselflies, in the suborder Zygoptera. They are commonly known as the broad-winged damselflies, demoiselles, or jewelwings. These rather large damselflies have wingspans of 50–80 mm, are often metallic-coloured, and can be differentiated from other damselflies by the broader connection between the wings and the body, as opposed to the abrupt narrowing seen in other damselfly families. The family contains some 150 species.
The Cordulegastridae are a family of Odonata (dragonflies) from the suborder Anisoptera. They are commonly known as spiketails. Some vernacular names for the species of this family are biddie and flying adder. They have large, brown or black bodies with yellow markings, and narrow unpatterned wings. Their bright eyes touch at a single point, and they can be found along small, clear, woodland streams, flying slowly 30 to 70 cm above the water. When disturbed, however, they can fly very rapidly. They usually hunt high in forest vegetation, and prefer to capture prey resting on leaves or branches.
Epiophlebia laidlawi, the Himalayan relict dragonfly, is one of four species of Epiprocta in the family Epiophlebiidae. They have at one time been classified as a suborder Anisozygoptera, considered as intermediate between the dragonflies and the damselflies, partly because the hind wings and fore wings are very similar in size and shape, and partly because the insect at rest holds them back over the body as damselflies do. These attributes now are known to be misleading however; the genus Epiophlebia shares a more recent ancestor with dragonflies and became separated from other Anisoptera in and around the uplifting Himalayas.
Epiprocta is one of the two extant suborders of the Odonata, which contains living dragonflies (Anisoptera), as well as Epiophlebioptera, which has a single known living genus Epiophlebia. Crown group Epiprocta first appeared during the Early Jurassic. It was proposed in 1992 by Heinrich Lohmann to accommodate the inclusion of the Anisozygoptera. The latter has been shown to be not a natural suborder, but rather a paraphyletic collection of lineages, so it has been combined with the previous suborder Anisoptera, the well-known dragonflies, into the Epiprocta. The old suborder Anisoptera is proposed to become an infraorder within the Epiprocta, whereas the "anisozygopterans" included here form the infraorder Epiophlebioptera. In Lohmann's original circumscription of the Epiprocta he also included the Tarsophlebiidae in it but Rehn (2003) placed it among the Zygoptera.
Epiophlebia is a genus of damsel-dragonfly native to the Indian subcontinent, East Asia, and Southeast Asia. It is the only living genus of Odonata to neither be a dragonfly nor a damselfly. It is the sole member of the family Epiophlebiidae, which is itself the sole living representative of the infraorder Epiophlebioptera.
Libelluloidea is a superfamily of dragonflies.
Epiophlebia superstes, the Japanese relict dragonfly, is one of the four species of the genus Epiophlebia, belonging to the family Epiophlebiidae, which is itself the sole living representative of the epiproctan infraorder Epiophlebioptera.
Xanthocnemis zealandica, commonly known as common redcoat damselfly, red damselfly, or red coat damselfly, is one of the most common native New Zealand damselflies. Adult damselflies are often seen flying around vegetation close to streams.
The Tarsophlebiidae is an extinct family of medium-sized fossil odonates from the Upper Jurassic and Lower Cretaceous period of Eurasia. They are either the most basal member of the damsel-dragonfly grade ("anisozygopteres") within the stem group of Anisoptera, or the sister group of all Recent odonates. They are characterized by the basally open discoidal cell in both pairs of wings, very long legs, paddle-shaped male cerci, and a hypertrophied ovipositor in females.
Bradinopyga geminata is a species of dragonfly in the family Libellulidae known commonly as the granite ghost. It is native to India, Sri Lanka and Thailand, where it is a common and widespread species.
Odonata are insects with an incomplete metamorphosis (hemimetabolous). The aquatic larva or nymph hatches from an egg, and develops through eight to seventeen instars before leaving the water and emerging as the winged adult or imago.
Calopterygoidea is a superfamily of damselflies in the order Odonata.
Platylestes platystylus, the green-eyed spreadwing, is a damselfly species in the family Lestidae. Although this species appears to be widespread, there are very few recent records. This species is known from old records from West Bengal in India, Myanmar, Thailand and Laos. There are recent records from Thailand, Vietnam, Laos and Kerala, South India.
Okanagrion is an extinct odonate genus in the damselfly-like family Dysagrionidae. The genus was first described in 2021 with a series of eight species included from early Eocene Okanagan Highlands sites in western North America. The genus is known from the Late Ypresian sediments exposed in northeast central Washington at Republic where five species are present, and from the coeval McAbee Fossil Beds near Cache Creek in Central British Columbia, where four species are present. The species richness is attributed to high latitude high alpha diversity resulting from climatic equitability during the Early Eocene in combination with resultant beta diversity between sites due to impassible topographical barriers.
Allenbya is an extinct odonate genus possibly in the damselfly-like family Dysagrionidae with the single included species Allenbya holmesae. The genus was first described in 2022 from an Early Eocene Okanagan Highlands site in western North America. The species is known from the late Ypresian sediments exposed around Princeton in Central British Columbia.
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: CS1 maint: multiple names: authors list (link)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.