Difference between revisions of "Neoptera" - New World Encyclopedia

From New World Encyclopedia
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Some groups within Neoptera do not have the ability to fold their wings back over their abdomen,  such as various [[butterfly|butterfies]] and [[moth]]s, but this is considered to have be a feature that was lost during evolutionary history (TOL 2003).  
 
Some groups within Neoptera do not have the ability to fold their wings back over their abdomen,  such as various [[butterfly|butterfies]] and [[moth]]s, but this is considered to have be a feature that was lost during evolutionary history (TOL 2003).  
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Neopterous insects include such as the [[beetle]]s, [[fly|flies]], [[wasp]]s, [[butterfly|butterflies]], true bugs, lice, [[bee]]s, [[flea]]s, [[ant]]s, stoneflies, [[grasshopper]]s, [[Mantodea|mantids]], and [[cockroach]]es).
  
 
==Overview==
 
==Overview==
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The Neoptera may be subdivided in various ways. The Integrated Taxonomic Information System (ITIS) lumps all neopteran orders together in this infraclass without subdivision. Other authorities recognize several [[superorder]]s within it.  
 
The Neoptera may be subdivided in various ways. The Integrated Taxonomic Information System (ITIS) lumps all neopteran orders together in this infraclass without subdivision. Other authorities recognize several [[superorder]]s within it.  
  
Almost universally accepted as a major division of Neoptera are the [[Exopterygota]] - [[hemimetabolous]] neopterans, in which the wings are already visible before the adult stage and no [[pupa]] or [[chrysalis]] stage occurs -, and the [[Endopterygota]], the [[holometabolous]] insects in which the wings develop inside the body during the [[larva]]l stage and only become external appendages during the pupa or chrysalis stage.
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Almost universally accepted as twos major division of Neoptera are the '''[[Exopterygota]]''', ([[metamorphosis#Insect metamorphosis|hemimetabolous]] neopterans, involving incomplete [[metamorphosis]] in which the wings are already visible before the adult stage and no [[pupa]] or [[chrysalis]] stage occurs, and the '''[[Endopterygota]]''', the [[metamorphosis#Insect metamorphosis|holometabolous]] insects involving complete metamorphosis in which the wings develop inside the body during the [[larva]]l stage and only become external appendages during the pupa or chrysalis stage. Endopterygota literally means "internal winged forms" while Exopterygota means "external winged forms." Although members of Exopterygota develop wings on the outside of their bodies without going through a true pupal stage, a few have something resembling a pupa (e.g., Aleyrodidae).
 
 
 
 
Neoptera is composed of the Endopterygota (insects with complete metamorphosis, such as beetles, flies, wasps, and butterflies), the Hemipteroid Assemblage (bugs, lice, and thrips), and the "lower Neoptera" (many living orders, such as Plecoptera or stoneflies, Orthoptera including grasshoppers, and Dictyoptera, including mantids and cockroaches).  
 
 
 
 
 
  
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Neoptera also may be subdivided into the '''Endopterygota''' (insects with complete metamorphosis, such as beetles, flies, wasps, and butterflies), the '''Hemipteroid Assemblage''' (bugs, lice, and thrips), and the '''"lower Neoptera"''' (the many other living orders, such as Plecoptera or stoneflies, [[Orthoptera]] including grasshoppers, and Dictyoptera, including [[Mantodea|mantids]] and [[cockroach]]es).
  
 
As of recently, there are several attempts to resolve the neopteran diversity further. While this appears to be less controversial than in the (apparently [[paraphyletic]]) "Palaeoptera," there are nonetheless lots of unresolved questions. For example, the [[hymenoptera]]ns, traditionally considered highly advanced due to their intricate [[social insects|social systems]], seem to be far more basal among the [[Endopterygota]], as suggested by their relatively [[plesiomorph]]ic [[anatomy]] and molecular data. The exact position of the proposed [[Dictyoptera]] is also uncertain, namely whether they are better considered [[Exopterygota]] or basal neopterans.
 
As of recently, there are several attempts to resolve the neopteran diversity further. While this appears to be less controversial than in the (apparently [[paraphyletic]]) "Palaeoptera," there are nonetheless lots of unresolved questions. For example, the [[hymenoptera]]ns, traditionally considered highly advanced due to their intricate [[social insects|social systems]], seem to be far more basal among the [[Endopterygota]], as suggested by their relatively [[plesiomorph]]ic [[anatomy]] and molecular data. The exact position of the proposed [[Dictyoptera]] is also uncertain, namely whether they are better considered [[Exopterygota]] or basal neopterans.
  
 
==Detailed classification==
 
==Detailed classification==
Here is a list of living and [[fossil]] neopteran orders, and the proposed superorders:
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Here is one particularly classification of living and [[fossil]] neopteran orders, as well as some  proposed superorders. Note that a number of [[taxonomy|taxonomies]] exist, including Dictyoptera as an order, with Blattodea, Isoptera, and Mantodea as suborders of Dictyoptera.
  
Superorder [[Exopterygota]]{{Verify source|date=August 2007}}<!-- most are more likely basal, such as mantidy, blattids, termites etc —>
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Superorder [[Exopterygota]]  
 
* [[Caloneurodea]] (fossil)
 
* [[Caloneurodea]] (fossil)
 
* [[Titanoptera]] (fossil)
 
* [[Titanoptera]] (fossil)
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[[Category:Life sciences]]
 
[[Category:Life sciences]]
  
{{credits|Neoptera|163640837}}
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{{credits|Neoptera|163640837|Pterygota|166887739|Exopterygota|165110778}}

Revision as of 16:59, 27 October 2007


Neopterans
Honeybee (order Hymenoptera)
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Subclass: Pterygota
Infraclass: Neoptera
Martynov, 1923
Superorders and orders

Superorder Exopterygota

  • Grylloblattodea (ice-crawlers)
  • Mantophasmatodea (gladiators)
  • Plecoptera (stoneflies)
  • Embioptera (webspinners)
  • Zoraptera (angel insects)
  • Dermaptera (earwigs)
  • Orthoptera (grasshoppers, etc)
  • Phasmatodea (stick insects)
  • Blattodea (cockroaches)
  • Isoptera (termites)
  • Mantodea (mantids)
  • Psocoptera (booklice, barklice)
  • Thysanoptera (thrips)
  • Phthiraptera (lice)
  • Hemiptera (true bugs)

Superorder Endopterygota

For fossil groups and possible future splits, see text.

Neoptera is a major taxonomic group of insects that includes almost all the winged insects and specifically those considered to be related by the ability to fold their wings back over their abdomen. Traditionally, they are one of two major groups within the subclass Pterygota (the winged insects), the other being Paleoptera, which lack the ability to fold their wings in this manner.

Some groups within Neoptera do not have the ability to fold their wings back over their abdomen, such as various butterfies and moths, but this is considered to have be a feature that was lost during evolutionary history (TOL 2003).

Neopterous insects include such as the beetles, flies, wasps, butterflies, true bugs, lice, bees, fleas, ants, stoneflies, grasshoppers, mantids, and cockroaches).

Overview

Insects, which are invertebrates comprising the Class Insecta, are the largest and (on land) most widely distributed taxon (taxonomic unit) within the Phylum Arthropoda. As arthropods, insects have jointed appendages, an exoskeleton (hard, external covering), segmented body, ventral nervous system, digestive system, open circulatory system, and specialized sensory receptors. Insects are distinguished from other arthropods by having three pairs of jointed legs; an abdomen that is divided into 11 segments and lacks any legs or wings; and a body separated into three parts (head, thorax, and abdomen), with one pair of antennae on the head. The true insects (that is, species classified in the Class Insecta) are also distinguished from all other arthropods in part by having ectognathous, or exposed, mouthparts. T

Most species of insects, but by no means all, have wings as adults. Winged insects are placed in the Subclass Pterygota. (Wingless insects, such as the silverfishes and bristletails, are placed in the subclass Apterygota.) Pterygota also includes some insect groups that are "secondarily wingless"; that is, it is considered that the ancestors of these insects had wings but were lost through the process of descent with modification.

Neoptera are those members of Pterygota that are able to fold their wings back over their abdomen, as a result of special structures at the base of their wings (TOL 2003). A key component of this folding mechanism is the pleural wing-folding muscle and the third axillary sclerite (TOL 2003). Neoptera generally is considered an "infraclass." Those insects that are not able to fold their wings in this manner—such as the mayflies and the order Odonata (dragonflies, damselflies), are placed in the infraclass Paleoptera. Some insects placed in Neoptera are not able to fold their wings back but this is considered to have been a feature that their ancestors had and was lost.

Subdivisions of Infraclass Neoptera

The Neoptera may be subdivided in various ways. The Integrated Taxonomic Information System (ITIS) lumps all neopteran orders together in this infraclass without subdivision. Other authorities recognize several superorders within it.

Almost universally accepted as twos major division of Neoptera are the Exopterygota, (hemimetabolous neopterans, involving incomplete metamorphosis in which the wings are already visible before the adult stage and no pupa or chrysalis stage occurs, and the Endopterygota, the holometabolous insects involving complete metamorphosis in which the wings develop inside the body during the larval stage and only become external appendages during the pupa or chrysalis stage. Endopterygota literally means "internal winged forms" while Exopterygota means "external winged forms." Although members of Exopterygota develop wings on the outside of their bodies without going through a true pupal stage, a few have something resembling a pupa (e.g., Aleyrodidae).

Neoptera also may be subdivided into the Endopterygota (insects with complete metamorphosis, such as beetles, flies, wasps, and butterflies), the Hemipteroid Assemblage (bugs, lice, and thrips), and the "lower Neoptera" (the many other living orders, such as Plecoptera or stoneflies, Orthoptera including grasshoppers, and Dictyoptera, including mantids and cockroaches).

As of recently, there are several attempts to resolve the neopteran diversity further. While this appears to be less controversial than in the (apparently paraphyletic) "Palaeoptera," there are nonetheless lots of unresolved questions. For example, the hymenopterans, traditionally considered highly advanced due to their intricate social systems, seem to be far more basal among the Endopterygota, as suggested by their relatively plesiomorphic anatomy and molecular data. The exact position of the proposed Dictyoptera is also uncertain, namely whether they are better considered Exopterygota or basal neopterans.

Detailed classification

Here is one particularly classification of living and fossil neopteran orders, as well as some proposed superorders. Note that a number of taxonomies exist, including Dictyoptera as an order, with Blattodea, Isoptera, and Mantodea as suborders of Dictyoptera.

Superorder Exopterygota

  • Caloneurodea (fossil)
  • Titanoptera (fossil)
  • Protorthoptera (fossil)
  • Plecoptera (stoneflies)
  • Embioptera (webspinners)
  • Zoraptera (angel insects)
  • Dermaptera (earwigs)
  • Orthoptera (grasshoppers, etc)

Proposed superorder Dictyoptera

  • Phasmatodea (stick insects - tentatively placed here)
  • Grylloblattodea (ice-crawlers - tentatively placed here)
  • Mantophasmatodea (gladiators - tentatively placed here)
  • Blattodea (cockroaches)
  • Isoptera (termites)
  • Mantodea (mantids)

Proposed superorder Paraneoptera

  • Psocoptera (booklice, barklice)
  • Thysanoptera (thrips)
  • Phthiraptera (lice)
  • Hemiptera (true bugs)

Superorder Endopterygota

  • Hymenoptera (ants, bees, etc.)
  • Coleoptera (beetles)
  • Strepsiptera (twisted-winged parasites)
  • Raphidioptera (snakeflies)
  • Megaloptera (alderflies, etc.)
  • Neuroptera (net-veined insects)

Proposed superorder Mecopteroidea/Antliophora

  • Mecoptera (scorpionflies, etc.)
  • Siphonaptera (fleas and snow fleas)
  • Diptera (true flies)
  • Protodiptera (fossil)

Proposed superorder Amphiesmenoptera

Incertae sedis

  • Glosselytrodea (fossil)
  • Miomoptera (fossil)

References
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