Systematics of the beetles

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External system

Within the subclass of flying insects (Pterygota), the beetles are part of the parentage of the new winged insects (Neoptera). Of these split over the Eumetabola the holometabolous insects from. The holometabolic insects, also called Endopterygota, are divided into the group of reticulated winged (Neuropterida) and Coleopteroida on the one hand and the hymenoptera (Hymenoptera) and Mecopteroida on the other. The Coleopteroida are further divided into beetles (Coleoptera) and fan-winged birds (Strepsiptera), which are therefore most closely related to the beetles. Their closest relatives are the camel neck flies (Raphidioptera), large-winged (Megaloptera) and reticulated winged (Neuroptera) in the reticulated winged group.

The following cladogram is derived from this:

 New winged wing (Neoptera)  
  Eumetabola  

 Paraneoptera


  Holometabola  

 remaining orders


  NN  
  Reticulated winged  (Neuropterida)  

 Camel neck flies (Raphidioptera)


  NN  

 Large winged (Megaloptera)


   

 Reticulated winged (Neuroptera)




  Coleopteroid  

 Beetle (Coleoptera)


   

 Fan winged (Strepsiptera)






   

 Paurometabola



Internal system

Tenomerga mucida as a representative of the Archostemata is one of the most original beetle species

The number of families varies considerably depending on the author and the classic system of beetles is therefore presented very inconsistently.

With over 350,000 species in 179 families , they represent the largest order from the class of insects and are divided into four sub- orders .

The group of Archostemata five are families expected that 40, mainly in tropical and subtropical occurring regions of species included. They are in a sister group relationship to the other three subfamilies and represent a very old line of beetles with primitive peculiarities, the morphology of which is very similar to the first beetles, which first appeared about 250 million years ago. However, the group is not related to the oldest beetles, as these belong to the stem line of the entire beetle. The beetles have only five abdominal sternites and they also lack the cervical sclerite between the head and prothorax and the external pleurs (lateral chitinous plates) of the prothorax. The hips ( coxa ) of your hind legs are flexible and the thigh rings (trochanters) are usually clearly visible. But they fold their wings just like the species of Myxophaga and Adephaga. They differ from the myxophaga also the fact that the tarsi are not fused with the Prätarsen.

The beetles of the suborder Myxophaga live underwater and all have in common that their tarsi and praetarsi are fused together. The three-part antennae of the larvae, their five-segment legs, on the last limb of the tarsi there is only one claw and the growing together of the trochantin , pleuras and the abdominal ventrites of the imagines would indicate a sister relationship between the Myxophaga and the Polyphaga. On the other hand, the veining of the wings and the folding of the wings speak for a sister relationship between Myxophaga and Adephaga.

As the second largest suborder with 14 families, the Adephaga already contain a large variety of different species. This group is also very old and can be dated back to the early Triassic , about 240 million years ago. Some of these are highly specialized species. There are fossil finds of both on land and in water species. The larvae of the Adephaga are adapted to the intake of liquid food, they have an overgrown labrum and no cutting surfaces ( molae ) on the mandibles. In the adults, the pleurs (lateral chitin plates) of the thorax are not fused with the upper side of the pronotum and therefore form a seam. The animals also have six sternas on the abdomen, the first three of which are fused together and divided by the coxae of the hind legs. Many species have defensive glands on the abdomen. It was assumed that the Adephaga are in a sister group relationship to the Myxophaga and Polyphaga, but the latest findings suggest that the Adephaga are more closely related to the Polyphaga.

More than 90 percent of the beetle species belong to the subordination of the Polyphaga . In the adults, the separation of the pleura of the prothorax and the upper side of the pronotum cannot be seen, but the pleura is fused with the trochantin. This means that a suture between the notum and sternum can be seen on the prothorax; the other subordinates have two visible sutures, between the sternum and pleurum and between notum and pleurum. The cervical sclerites between the head and prothorax are present, the coxae of the hind legs are mobile and do not share the first ventrit, and the wing folding differs from that of the other three suborders. In the three other suborders, cells are formed between radial artery and cubital artery through cross veins, between which the median vein runs and splits. In the Polyphaga there is no cell formation and a maximum of one cross vein between the radius and the median.

The relationships between the four subordinates can be illustrated in the following cladogram:

 Beetle  
  NN  

 Myxophaga


  NN  

 Adephaga


   

 Polyphaga




   

 Archostemata



Taxonomy of the order of the beetles

The following system of beetles is carried out down to the family level and is based on Beutel / Leschen (2005), supplemented and updated by Leschen / Beutel / Lawrence (2010).

Subordination Archostemata

Suborder Myxophaga

Submission to Adephaga

Subordination to Polyphaga

Partial order staphyliniformia

Superfamily Hydrophiloidea
Superfamily Staphylinoidea

Partial order Scarabaeiformia

Superfamily Scarabaeoidea

Partial order Elateriformia

Superfamily Scirtoidea
Superfamily Dascilloidea
Superfamily Buprestoidea
Superfamily Byrrhoidea
Superfamily Elateroidea
Incertae sedis

Partial order Derodontiformia

Superfamily Derodontoidea

Partial order of Bostrichiformia

Superfamily Bostrichoidea

Partial order Cucujiformia

Superfamily Lymexyloidea
Superfamily Cleroidea
Superfamily Cucujoidea
Superfamily Tenebrionoidea
Superfamily Chrysomeloidea
Superfamily Curculionoidea

supporting documents

Individual evidence

  1. ↑ a b c d Peter S. Cranston, Penny J. Gullan: Phylogeny of Insects . In: VH Resh and RT Cardé (eds.): Encyclopedia of Insects . Academic Press. Amsterdam 2003 ( PDF ( Memento of the original from February 4, 2012 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this note. ). @1@ 2Template: Webachiv / IABot / entomology.ucdavis.edu
  2. ^ Rolf G. Beutel, Richard AB Leschen: Handbuch der Zoologie - Coleoptera, Beetles, Volume 1: Morphology and Systematics (Archostemata, Adephaga, Myxophaga, Polyphaga partim) . 1st edition. de Gruyter , 2005, ISBN 3-11-017130-9 (English).
  3. ^ Richard AB Leschen, Rolf G. Beutel, John F. Lawrence: Handbuch der Zoologie - Coleoptera, Beetles, Volume 2: Morphology and Systematics (Elateroidea, Bostrichiformia, Cucujiformia partim) . de Gruyter, 2010, ISBN 978-3-11-019075-5 (English).

literature

  • Rolf G. Beutel, Richard AB Leschen: Handbuch der Zoologie - Coleoptera, Beetles, Volume 1: Morphology and Systematics (Archostemata, Adephaga, Myxophaga, Polyphaga partim) . 1st edition. de Gruyter , 2005, ISBN 3-11-017130-9 (English).
  • Richard AB Leschen, Rolf G. Beutel, John F. Lawrence: Handbuch der Zoologie - Coleoptera, Beetles, Volume 2: Morphology and Systematics (Elateroidea, Bostrichiformia, Cucujiformia partim) . de Gruyter, 2010, ISBN 978-3-11-019075-5 (English).