Spercheus is a genus of aquatic beetles which are placed in a family of their own, Spercheidae within the Hydrophiloidea. About 20 species are known from around the world except the Nearctic with the majority being from the Oriental and Afrotropical Realms.
Tiger beetles are a family of beetles, Cicindelidae, known for their aggressive predatory habits and running speed. The fastest known species of tiger beetle, Rivacindela hudsoni, can run at a speed of 9 km/h, or about 125 body lengths per second. As of 2005, about 2,600 species and subspecies were known, with the richest diversity in the Oriental (Indo-Malayan) region, followed by the Neotropics. While historically treated as a subfamily of ground beetles (Carabidae) under the name Cicindelinae, several studies since 2020 indicated that they should be treated as a family, the Cicindelidae, which are a sister group to Carabidae within the Adephaga.
Ground beetles are a large, cosmopolitan family of beetles, the Carabidae, with more than 40,000 species worldwide, around 2,000 of which are found in North America and 2,700 in Europe. As of 2015, it is one of the 10 most species-rich animal families. They belong to the Adephaga. Members of the family are primarily carnivorous, but some members are phytophagous or omnivorous.
The whirligig beetles are water beetles, comprising the family Gyrinidae that usually swim on the surface of the water if undisturbed, though they swim underwater when threatened. They get their common name from their habit of swimming rapidly in circles when alarmed, and are also notable for their divided eyes which are believed to enable them to see both above and below water. The family includes some 700 extant species worldwide, in 15 genera, plus a few fossil species. Most species are very similar in general appearance, though they vary in size from perhaps 3 mm to 18 mm in length. They tend to be flattened and rounded in cross section, in plain view as seen from above, and in longitudinal section. In fact their shape is a good first approximation to an ellipsoid, with legs and other appendages fitting closely into a streamlined surface. Whirligig beetles belong to the beetle suborder Adephaga, which also includes ground beetles and diving beetles.
The Adephaga are a suborder of beetles, and with more than 40,000 recorded species in 10 families, the second-largest of the four beetle suborders. Members of this suborder are collectively known as adephagans. The largest family is Carabidae which comprises most of the suborder with over 40,000 species. Adephaga also includes a variety of aquatic beetles, such as predaceous diving beetles and whirligig beetles.
The Archostemata are the smallest suborder of beetles, consisting 45 living species in five families. They are an ancient lineage with a number of primitive characteristics. Antennae may be thread-shaped (filiform) or like a string of beads (moniliform). This suborder also contains the only beetles where both sexes are paedogenic, Micromalthus debilis. Modern archostematan beetles are considered rare, but were more diverse during the Mesozoic. The term "Archostemata" is used more broadly by some authors to include both modern archostematans as well as stem-group beetles like "protocoleopterans", which some modern archostematans closely resemble to due to their plesiomorphic morphology. Genetic research suggests that modern archostematans are a monophyletic group. Some genetic studies have recovered archostematans as the sister group of Myxophaga.
The Trachypachidae are a family of beetles that generally resemble small ground beetles, but that are distinguished by the large coxae of their rearmost legs. There are only six known extant species in the family, with four species of Trachypachus found in northern Eurasia and northern North America, and two species of Systolosoma in Chile and Argentina. They were much more diverse in the past, with dozens of described species from the Mesozoic.
Amphizoa is a genus of aquatic beetles in the suborder Adephaga, placed in its own monogeneric family, Amphizoidae. There are five known species of Amphizoa, three in western North America and two in the eastern Palearctic. They are sometimes referred to by the common name troutstream beetles.
Myxophaga is the second-smallest suborder of the Coleoptera after Archostemata, consisting of roughly 65 species of small to minute beetles in four families. The members of this suborder are aquatic and semiaquatic, and feed on algae.
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.
Jurodidae is a family of beetles that was originally described for the extinct genus Jurodes, known from the Middle-Late Jurassic of Asia. In 1996, a living species, Sikhotealinia zhiltzovae was discovered in the Sikhote-Alin mountains in Siberia, and assigned to this family. Their placement is uncertain, but are usually considered archostematans. In one study, Sikhotealinia and Jurodes were considered a sister group to all other archostematan beetles. However, other authors have considered them to mix characteristics of Archostemata, as well as Polyphaga and Adephaga.
Histeroidea is a superfamily of beetles in the infraorder Staphyliniformia.
Hygrobia is a genus of aquatic beetles native to Europe, North Africa, China and Australia. It is the only genus in the family Hygrobiidae, also known as the Paelobiidae. These are known commonly as squeak beetles or screech-beetles.
Rhysodinae is a subfamily in the family Carabidae. There are 19 genera and at least 380 described species in Rhysodinae. The group of genera making up Rhysodinae had been treated as the family Rhysodidae in the past, and subsequent DNA analysis then placed it within Carabidae, where it was sometimes treated as the tribe Rhysodini, but the most recent analyses place it as a subfamily in a clade along with subfamilies Paussinae and Siagoninae, forming a sister to the remaining Carabidae.
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.
Aspidytes is a genus of aquatic beetles in the family Aspidytidae, first recorded in 2002 from specimens in South Africa. The genus contains the single species Aspidytes niobe. Originally a second species from China was placed in the same genus but has later been transferred to Sinaspidytes. The aquatic beetle is 6.5 - 7.2 mm long and lives in hygropetric habitats.
Sinopyrophorus is a genus of bioluminescent hard-bodied clicking beetles in the superfamily Elateroidea, and is the sole member of the recently recognized family Sinopyrophoridae. The genus currently contains a single species, Sinopyrophorus schimmeli, which was described in 2019 from the subtropical evergreen broadleaf forests of western Yunnan, China.
Condylognatha or Panhemiptera is a monophyletic grouping (superorder) that contains Hemiptera and Thysanoptera (thrips). Condylognatha belongs to Paraneoptera, which include its sister group, lice (Psocodea).
Sinaspidytes is a genus of aquatic beetles in Aspidytidae, first recorded in 2003 from specimens in the Shaanxi province, China. It is monotypic, with the only species being Sinaspidytes wrasei. Originally this species was placed in the genus Aspidytes with a second species from South Africa, but was later transferred to Sinaspidytes. The genus contains the single species S. wrasei. The aquatic beetle is 4.8 - 5.2 mm long and lives in hygropetric habitats.
