Paws beetle ( Timarcha tenebricosa ), as a representative of the leaf beetle Chrysomeloidea
The Polyphaga are a suborder of beetles ( Coleoptera). It includes more than 320,000 species in 151 families the majority of all beetles and is thus not only their diverse subordination but also the most derived with the groups. The confirmed in almost all systematic classifications of beetles grouping was first described by Carlo Emery 1886.
In the imagos is the separation of the pleura of the prothorax and the upper side forming Sklerits: the pronotum, not to recognize the strongly reduced pleura is movable and merged with the Trochantin. The stability of the prothorax is maintained by a seam directly between the front portion of the Prosternum and pronotum. It follows that only a seam between Notum and sternum on the prothorax is recognizable, but the other suborders of beetles have two visible seams between the sternum and Pleurum and between Notum and Pleurum. The wing folding differs from that of the other three suborders. These are located between the posterior branch of the radial artery ( RP ) and the posterior branch of the median vein MP1 2 ( MA is fused at the beetles with RP and not visible) two cross- veins, which define a distinctive cell, referred to as the " oblongum " will. In the Polyphaga there is no cell formation and a maximum of a cross- vein between the radius and the medians. The corresponding wing area is more flexible and can be folded at the folding wings.
The monophyly of the group is supported by the features described above, which may represent autapomorphies. Some scientists have the same characteristics but are valued differently, it could also be Symplesiomorphien inside and outside the order of the beetles, depending on the interpretation of the phylogenetic relationship. About these features, also the merger of Propleura with the Trochantin is a derived feature of the Polyphaga, which also occurs in the Myxophaga and therefore supports a sister group relationship between these submissions. With this suborder Polyphaga the share disable the feature that the larvae missing a leg segment at their thus five-membered legs and they have only a single claw on the tarsi. The absence of the sterno - coxal muscle on the prothorax and the coxa - subalar muscle on the mesothorax are probably based more autapomorphies of Polyphaga .. In addition, only the Polyphaga have in the neck two sclerotized clips that Cervikalsklerite.
The monophyly of the group is also by phylogenetic trees (based on homologous DNA sequences ) strongly supported.
Based on the basal joints of the abdomen two major groups were distinguished within the Polyphaga by Kolbe in his work from 1908. The Haplogastra include the taxa in which the second segment laterally remnants of the pleura and sterna are present in the Symphiogastra of the hind legs is the second to the third sternite fused and below the hips ( coxae ) covered. Although these two groups is also supported by the work of Kukalová - Peck & Lawrence in 1993, the corresponding a " hydrophiloide " and a different " eucinetoide " line of Polyphaga basis of features on the wings and even the monophyly of these groups by a cladistic analysis of characteristics of larvae and adults by Hansen in 1997 is confirmed, it is still unclear whether this allocation is justified in subgroups. Bags & Leschen Add to this that the work of Kukalová - Peck & Lawrence on a single, albeit complex trait system involved and the work of Hansen mainly relied on the Staphylinoidea and hydro Philo Idea and beyond just only three species from the Scarabaeiformia and the " eucinetoiden " line included. In addition, recent studies indicate a need for revision of the classification of Polyphaga, since the structure of several high Untertaxa by molecular genetic studies, it was doubtful. To suggest, for example, numerous characteristics suggest that the Scirtoidea not belong to the Elateriformia, but represent the most primitive Polyphaga.
The Polyphaga are currently divided into five sub- orders with 16 superfamilies:
- Staphyliniformia Hydro Philo Idea
- Scarabaeiformia Scarabaeoidea
- Elateriformia Scirtoidea
- Derodontiformia Derodontoidea
- Bostrichiformia Bostrichoidea
- Cucujiformia Lymexyloidea