Polyphaga is the largest and most diverse suborder of beetles. It comprises 144 families in 16 superfamilies, and displays an enormous variety of specialization and adaptation, with over 350,000 described species, or approximately 90% of the beetle species so far discovered.
The Elateroidea are a large superfamily of beetles. It contains the familiar click beetles, fireflies, and soldier beetles and their relatives. It consists of about 25,000 species.
Cleroidea is a small superfamily of beetles containing over 10,000 species. Most of the members of the group are somewhat slender, often with fairly soft, flexible elytra, and typically hairy or scaly.
Byrrhoidea is a superfamily of beetles belonging to Elateriformia that includes several families which are either aquatic or associated with a semi-aquatic habitat. Other than the superfamily Hydrophiloidea, most of the remaining Polyphagan beetles which are aquatic are in this superfamily.
Corylophidae is a family of minute hooded beetles, sometimes called minute fungus beetles, in the superfamily Coccinelloidea. There are about 18 genera and at least 120 described species in Corylophidae. They feed on microfungi such as molds, and are often found associated with bark, as well as in leaf litter and other decaying vegetation. In older literature, the family name was often given as Orthoperidae.
Scirtoidea is a superfamily of beetles. It is traditionally considered to consist of four families: Clambidae, Decliniidae, Eucinetidae and Scirtidae. However, genetic studies have suggested that Clambidae and Eucinetidae belong to a separate superfamily Clamboidea, which also includes Derodontidae. Scirtoidea and Clamboidea are the two earliest diverging lineages of living polyphagans.
Nosodendridae is a family of beetles, with only 67 species in three extant genera, which are found worldwide. Nosodendron, the largest genus, is found in forests and attracted to yeast generated slime on the wounds of trees, and likely consumes fermented substances as well as fungi and microorganisms. Several additional genera and species are known from the fossil record. Nosodendridae is considered to be an isolated lineage within Polyphaga, being the sister group to the clade containing Staphyliniformia, Bostrichoidea and Cucujiformia.
Alexiidae is a family of beetles. It contains a single genus, Sphaerosoma, formerly included within the family Cerylonidae, with around 50 species which are native to the western Palearctic. Species of Sphaerosoma are very small, around 1 to 2 mm in length rounded beetles with clubbed antennae. They are fungivores, having been observed feeding on mushrooms, and have been also been found in leaf litter and on decaying bark.
Discolomatidae is a family of beetles in the superfamily Coccinelloidea. It contains approximately 400 species in 16 genera, which are found mostly found in tropical regions, being largely absent from temperate regions. They have generally been found associated with decaying vegetation or fungi, and are therefore assumed to be fungivorous. Some species are associated with ants (myrmecophily). The larvae have unusual flattened sclerotised bodies, with heads that are concealed from above.
Eucnemidae, or false click beetles, are a family of elateroid beetles including about 1700 species distributed worldwide.
The Protocoleoptera are a paraphyletic group of extinct beetles, containing the earliest and most primitive lineages of beetles. They represented the dominant group of beetles during the Permian, but were largely replaced by modern beetle groups during the following Triassic. Protocoleopterans typically possess prognathous (horizontal) heads, distinctive elytra with regular window punctures, culticles with tubercles or scales, as well as a primitive pattern of ventral sclerites, similar to the modern archostematan families Ommatidae and Cupedidae. They are thought to have been xylophagous and wood boring.
Clambidae is a family of beetles. They are known commonly as the minute beetles or the fringe-winged beetles. They are found worldwide on every continent except Antarctica.
Omethidae is a family of Elateroidea sometimes known as the false soldier beetles. They are native to South, Southeast and Eastern Asia and the Americas. Their biology is obscure and their larvae are unknown. They appear to inhabit vegetation in or surrounding forests, and are probably active during the day.
Agapytho is the only genus of beetles in the family Agapythidae. The genus contains a single species, Agapytho foveicollis, which is endemic to New Zealand. Larvae and adults are found on sooty mold growing on Nothofagus trees. Gut contents indicate that at least adult Agapytho consume the sooty mould as part of their diet.
Mauroniscidae is a family of cleroid beetles, formerly included in the family Melyridae. There are presently five or six genera and roughly 30 described species in Mauroniscidae, all of which are native to the Americas. Almost nothing is known about their biology.
Metaxina is the only genus in the beetle family Metaxinidae. Its only species is Metaxina ornata. It endemic to the South island of New Zealand, where it is associated with sooty mold growing on Nothofagus trees. Both the larvae and adults are likely predaceous, feeding on insects and other arthropods. It is considered to be a member of the superfamily Cleroidea. Genetic studies have suggested that Metaxina should be considered a member of Chaetosomatidae, rather than constituting its own family.
Myrabolia is the only genus in the beetle family Myraboliidae in the superfamily Cucujoidea. It has about 13 species, found in Australia. Adults and possibly larvae live under the bark of Eucalyptus trees.
Priasilphidae is a family of beetles in the superfamily Cucujoidea. They have a Gondwanan distribution, with the three known genera Chileosilpha, Priasilpha and Priastichus being native to Chile, New Zealand and Tasmania respectively. Most species are flightless, lacking wings. Priasilphids inhabit decaying wood and moss in forest habitats. They are likely mycophagous, feeding on fungi.
Promecheilidae is a family of beetles in the superfamily Tenebrionoidea. They were formerly included in a family called Perimylopidae. They are found in southern South America and associated archipelagos like South Georgia and the Falklands, New Zealand and Tasmania. Some species are associated tree ferns and moss-covered dead wood, and other forested habitats, while others are associated with peat bogs, grasslands and coastal habitats. They are probably phytophagus, feeding on lichen, moss, and other plant material.
Tasmosalpingus is the only genus in the beetle family Tasmosalpingidae. There are two species in Tasmosalpingus, found in Australia in Tasmania and Victoria. Adults have been collected using malaise traps, while a possible larval specimen was found under the bark of the podocarp Phyllocladus aspleniifolius. Gut contents indicate that they are mycophagous, feeding on fungal hyphae.
