Polyphaga

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{{Taxobox | color = pink | name = Polyphaga | image = Tetraopes tetrophthalmus-1.jpg | image_width = 250px | image_caption = Milkweed beetle, Tetraopes tetrophthalmus | regnum = Animalia | phylum = Arthropoda | classis = Insecta | ordo = Coleoptera | subordo = Polyphaga | subordo_authority = Emery, 1886 | subdivision_ranks = Infraorders | subdivision = Bostrichiformia
Cucujiformia
Elateriformia
Scarabaeiformia
Staphyliniformia }} The Polyphagans are the biggest and most diverse suborder of beetles. Polyphaga is comprised of 16 superfamilies and 144 families and display an enormous variety of specialization and adaptation, with over 300,000 described species, or approximately 90% of the beetle species so far discovered.

1 Characteristics
2 Classification
3 References
4 External links

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Characteristics

The prothoracic pleuron is not externally visible, but is fused with the trochantin and remnant internally as a “cryptopleuron". Thus one suture between the notum and the sternum is visible in the prothorax in polyphagans, whereas two sutures (the sternopleural and notopleural) often are visible externally in other suborders (unless secondary fusion between the sclerites obfuscates the sutures, as in the genus Micromalthus).

The transverse fold of the hind wing never crosses MP, cervical sclerites are present, and hind coxae are mobile and do not divide the first ventrite. Female polyphagan beetles have telotrophic ovarioles, which is a derived condition within beetles.

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Classification

There are 5 infraorders :

Bostrichiformia - including furniture beetles and skin beetles.
Cucujiformia - includes lady beetles, longhorn beetles, weevils and leaf beetles.
Elateriformia - includes click beetles
Scarabaeiformia - includes scarab beetles and stag beetles.
Staphyliniformia - includes rove beetles and water beetles.

The internal classification of Polyphaga involves several superfamilies or series, whose constituents are relatively stable, although some smaller families (whose rank even is disputed) are allocated to different clades by different authors. Large superfamilies include Hydrophiloidea, Staphylinoidea, Scarabaeoidea, Buprestoidea, Byrrhoidea, Elateroidea, and Bostrichoidea.

The infraorder Cucujiformia includes the vast majority of phytophagous (plant-eating) beetles, united by cryptonephric Malpighian tubules of the normal type, a cone ommatidium with open rhabdom, and lack of functional spiracles on the eighth abdominal segment. Constituent superfamilies of Cucujiformia are Cleroidea, Cucujoidea, Tenebrionoidea, Chrysomeloidea, and Curculionoidea. Evidently adoption of a phytophagous lifestyle correlates with speciosity in beetles, with Cucujiformia, especially weevils (Curculionoidea), forming a major radiation.