Difference between revisions of "Damselfly" - New World Encyclopedia

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* Lohmann, H. 1996. Das phylogenetische system der Anisoptera (Odonata). ''Deutsche Entomologische Zeitschrift'' 106(9): 209-266.
 
* Lohmann, H. 1996. Das phylogenetische system der Anisoptera (Odonata). ''Deutsche Entomologische Zeitschrift'' 106(9): 209-266.
 
* Rehn, A. C. 2003. [http://www.blackwell-synergy.com/doi/pdf/10.1046/j.1365-3113.2003.00210.x Phylogenetic analysis of higher-level relationships of Odonata]. ''Systematic Entomology'' 28(2): 181-240. Retrieved September 30, 2007.
 
* Rehn, A. C. 2003. [http://www.blackwell-synergy.com/doi/pdf/10.1046/j.1365-3113.2003.00210.x Phylogenetic analysis of higher-level relationships of Odonata]. ''Systematic Entomology'' 28(2): 181-240. Retrieved September 30, 2007.
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* Trueman, John W. H. and Rowe, Richard J. 2008. [http://tolweb.org/Odonata/8266 Odonata. Dragonflies and damselflies]. Version 20 March 2008. http://tolweb.org/Odonata/8266/2008.03.20  in The Tree of Life Web Project, http://tolweb.org/
  
  
 
==External links==
 
==External links==
{{commonscat|Zygoptera}}
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{{wikispecies|Zygoptera}}
 
 
*[http://www.cirrusimage.com/damselfly_American_Rubyspot.htm American Rubyspot Damselfly ''Hetaerina americana'' diagnostic photos and information]
 
*[http://www.cirrusimage.com/damselfly_American_Rubyspot.htm American Rubyspot Damselfly ''Hetaerina americana'' diagnostic photos and information]
 
*[http://www.cirrusimage.com/damselfly_Enallagma_civile.htm Familiar Bluet Damselfly ''Enallagma civile'']
 
*[http://www.cirrusimage.com/damselfly_Enallagma_civile.htm Familiar Bluet Damselfly ''Enallagma civile'']

Revision as of 22:21, 4 June 2008

Damselflies
Blue Ringtail, Austrolestes annulosus
Blue Ringtail, Austrolestes annulosus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Odonata
Suborder: Zygoptera
Selys, 1854
Families

Amphipterygidae
Calopterygidae - Demoiselles
Chlorocyphidae - Jewels
Coenagrionidae - Pond Damselflies
Dicteriadidae - Barelegs
Euphaeidae - Gossamerwings
Hemiphlebidae - Reedlings
Isosticidae - Narrow-wings
Lestidae - Spreadwings
Lestoididae
Megapodagrionidae - Flatwings
Perilestidae - Shortwings
Platycnemididae - White-legged Damselflies
Platystictidae - Forest Damselflies
Polythoridae - Bannerwings
Protoneuridae - Pinflies
Pseudostigmatidae - Forest Giants
Synlestidae - Sylphs
†Zacallitidae

The Damselfly (Suborder Zygoptera) is an insect in the Order Odonata. Damselflies are similar to dragonflies, but the adults can be differentiated by the fact that the wings of most damselflies are held along the body when at rest. Furthermore, the hindwing of the damselfly is essentially similar to the forewing, while the hindwing of the dragonfly broadens near the base, caudal to the connecting point at the body. Damselflies are also usually smaller, weaker fliers than dragonflies, and their eyes are separated.

Dragonfly is the common name for any insect belonging to the infraorder (or suborder) Anisoptera of the order Odonata, characterized by an elongated body, large multifaceted eyes, and two pairs of strong transparent wings, which at rest are typically held out to the side or out and downward. In a broader sense, "dragonfly" is used to designate any insect in Epiprocata (Bechly 1996), which is a relatively new suborder that was created and subsumes as an infraorder of the previous suborder Anisoptera, the "true dragonflies."


Overview and description

As with all members of the arthropod class Insecta, dragonflies have three pairs of jointed appendages, exposed mouth parts, an exoskeleton, a segmented abdomen that lacks any legs or wings, and one pair of antennae on the head.

Odonata is an order of insects encompassing dragonflies and damselflies, with members characterized by large, compound eyes, chewing mouth parts, a long and slender abdomen, and multi-veined wings that are typically clear or transparent. Members of Odonata characteristically have large rounded heads, legs that facilitate catching prey (other insects) in flight, two pairs of long, transparent wings that move independently, and elongated, ten-segmented abdomens.

Wing structure of a dragonfly

In most families of Odonata, the wings, which are large, multi-veined, and slender, have an opaque structure on the leading edge near the tip of the wing, called the pterostigma. Males have unique secondary genitalia on the underside of the second and third abdominal segments, which are distinct from the actual genital opening located near the tip of the abdomen (Grzimek et al. 2004).

In most families, the wings, which are large, multi-veined, and slender, have an opaque structure on the leading edge near the tip of the wing, called the pterostigma. This actually is a thickened, blood–filled, and often colorful area called a cell. Cell in this case means a closed area of an insect wing bounded by veins. The functions of the pterostigma are not fully known, but it most probably has an aerodynamic effect as well as 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, thus, reduce the energy consumption of flying. A pterostigma is also found among other insects, like bees.

Males have unique secondary genitalia on the underside of the second and third abdominal segments, which are distinct from the actual genital opening located near the tip of the abdomen (Grzimek et al. 2004).


Within Odonata, the two main groups are the damselflies (suborder Zygoptera) and the dragonflies (suborder Epiprocta), with true dragonflies in infraorder Anisoptera. Dragonflies tend to be large insects with four elongate, membranous wings with characteristic, net-like veins. The antennae tend to be very small.

The two main groups are the damselflies (suborder Zygoptera) and the dragonflies (suborder Epiprocta), with true dragonflies in infraorder Anisoptera. Although generally fairly similar, dragonflies differ from damselflies in several, easily recognizable traits. Dragonflies are strong fliers with fairly robust bodies and at rest hold their wings either out to the side or out and downward (or even somewhat forward). Damselflies tend to be less robust, even rather weak appearing in flight, and when at rest most species hold their wings folded back over the abdomen (see photograph below, left). Dragonfly eyes occupy much of the animal's head, touching (or nearly touching) each other across the face. In damselflies, there is typically a gap between the eyes.


Wingspans range from just 20 millimeters (0.8 inches) in the damselfly Agriocnemis femina up to 190 centimeters (7.5 inches) in the giant Central American damselfly, Megaloprepus coerulatus,. Some very large fossil species have been discovered as well.


Dragonflies versus damselflies

Dragonfly, Orthetrum cancellatum, with wings out to the side while at rest
A damselfly (Coenagrionidae), with wings folded together over the abdomen

Although generally fairly similar, dragonflies differ from damselflies (suborder Zygotpera) in several, easily recognizable traits. Dragonflies have fairly robust bodies, are strong fliers, and at rest hold their wings either out to the side or out and downward (or even somewhat forward). Damselflies tend to be less robust, even appearing rather weak in flight, and when at rest hold their wings either folded together back above the abdomen or held slightly open above (such as in the family Lestidae). Also, the hind wing of the dragonfly broadens near the base, caudal to the connecting point at the body, while the hind wing of the damselfly is essentially similar to the fore wing.

Dragonfly eyes typically occupy much of the animal's head, touching (or nearly touching) each other across the face, with notable exceptions to this being in the Petaluridae (Petaltails) and the Gomphidae (Clubtails). In damselflies, there is typically a gap between the eyes.

Both are members of the Odonata, making their life cycles similar.


Life cycle

Head of a damselfly

Damselflies undergo incomplete metamorphosis, with an aquatic nymphal stage. The female lays eggs in water, sometimes in underwater vegetation, or high in trees in bromeliads and other water-filled cavities. Nymphs are carnivorous, feeding on daphnia, mosquito larvae, and various other small aquatic organisms. The gills of damselfly nymphs are large and external, resembling three fins at the end of the abdomen. After moulting several times, the winged adult emerges and eats flies, mosquitoes, and other small insects. Some of the larger tropical species are known to feed on spiders, hovering near the web and simply plucking the spider from its perch.

Gallery

Mating Damselflies

References
ISBN links support NWE through referral fees

  • Grzimek, B., D. G. Kleiman, V. Geist, and M. C. McDade. Grzimek's Animal Life Encyclopedia. Detroit: Thomson-Gale, 2004. ISBN 0307394913.
  • Lohmann, H. 1996. Das phylogenetische system der Anisoptera (Odonata). Deutsche Entomologische Zeitschrift 106(9): 209-266.
  • Rehn, A. C. 2003. Phylogenetic analysis of higher-level relationships of Odonata. Systematic Entomology 28(2): 181-240. Retrieved September 30, 2007.


External links

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