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.
Macrodontia cervicornis, also known as the Sabertooth Longhorn beetle, is one of the largest beetles, if one allows for the enormous mandibles of the males, from which it derives both of the names in its binomen: Macrodontia means "long tooth", and cervicornis means "deer antler". Measurements of insect length normally exclude legs, jaws, or horns, but if jaws are included, the longest known specimen of M. cervicornis is 17.7 cm; the longest known specimen of Dynastes hercules, a beetle species with enormous horns, is 17.5 cm, and the longest known beetle excluding either jaws or horns is Titanus giganteus, at 16.7 cm.
Nemonychidae is a small family of weevils, placed within the primitive weevil group because they have straight rather than elbowed antennae. They are often called pine flower weevils. As in the Anthribidae, the labrum appears as a separate segment to the clypeus, and the maxillary palps are long and projecting. Nemonychidae have all ventrites free, while Anthribidae have ventrites 1-4 connate or partially fused. Nemonychidae lack lateral carinae on the pronotum, while these are usually present, though may be short, in Anthribidae.
Laemophloeidae, "lined flat bark beetles," is a family in the superfamily Cucujoidea characterized by predominantly dorso-ventrally compressed bodies, head and pronotal discs bordered by ridges or grooves, and inverted male genitalia. Size range of adults is 1–5 mm (0.04–0.2 in) in length. Currently, it contains 40 genera and about 450 species, and is represented on all continents except Antarctica; species richness is greatest in the tropics.
Silvanidae, "silvan flat bark beetles", is a family of beetles in the superfamily Cucujoidea, consisting of 58 described genera and about 500 described species. The family is represented on all continents except Antarctica, and is most diverse at both the generic and species levels in the Old World tropics.
Deinophloeus is a small genus of beetles in the family Laemophloeidae restricted to the New World, where five species are known to occur from Arizona south to Panama. Members of the genus are rather large for the family, ranging from about 2.5 mm to more than 4 mm in length. Members of the genus are characterized by the absence of a frontoclypeal suture, closed procoxal cavities and, in the male, elongate mandibles, clypeal horns, and modified elytral apices. The immature stages are unknown, and nothing is known about their habits or habitats.
Dysmerus is a genus of beetles in the family Laemophloeidae. Restricted to the New World, until recently Dysmerus included only the type species, D. basalis, described from Florida in the late 19th Century. A recent revision resurrected two incorrectly synonymized species and recognized an additional 12 new species, so that the genus currently contains 15 species.
Placonotus is a genus of beetles in the family Laemophloeidae. There are 40 currently recognized species, known from all continents except Antarctica. Placonotus species are small (~2mm), elongate, flattened beetles, characterized by long filiform antennae, presence of a frontoclypeal suture, open anterior coxal cavities, and broadly rounded intercoxal process of abdominal ventrite III. Males have the 8th abdominal segment modified to form claspers used during mating. Adults and larvae are found under dead bark, where they feed on fungi. Currently recognized species are:
Passandridae, the "parasitic flat bark beetles," are a family of beetles notable for being one of the very few beetle families with larvae that are, as far as known, exclusively ectoparasitic on the immature stages of other beetles and Hymenoptera.
Pediacus is the largest genus in the family Cucujidae. It contains 31 currently recognized species. Pediacus adults are relatively small (2.7-7.0mm), flattened brownish beetles with no or very small temples, and short antennae with a distinct club. Male genitalia are inverted and possess a short flagellum.
Gelae is a genus of round fungus beetles belonging to the family Leiodidae. The beetles are found in different parts of Central and North America. They are small and rounded, feeding on slime moulds. They were originally placed in the genus Agathidium following the discovery of the first species, G. cognatum, in 1878. The taxonomic position was revised with description of new species in 2004 by American entomologists Kelly B. Miller and Quentin D. Wheeler. Upon creation of the new genus, the five new species are Gelae baen, G. belae, G. donut, G. fish, and G. rol.
Geodorcus alsobius, or Moehau stag beetle, is a large flightless species of stag beetle in the family Lucanidae. It is found only on Mt Moehau, the highest mountain in the Moehau Range on the Coromandel Peninsula in New Zealand.
Geodorcus auriculatus is a large flightless stag beetle that is found in the southern part of the Coromandel Peninsula and on Mount Te Aroha in the Kaimai range.
Geodorcus novaezealandiae is a large flightless species of stag beetle in the family Lucanidae. It is the type species and smallest member of the genus Geodorcus. It is endemic to New Zealand.
Geodorcus servandus is a large flightless species of stag beetle in the family Lucanidae. It was discovered by P.R. Kettle in December 1960 and this holotype specimen is held in the New Zealand Arthropod Collection. It was first described by Beverley Holloway in 2007. Its type location is Mount Tuhua summit, near Lake Kaniere on the West Coast of New Zealand. The name servandus is a Latin word meaning "[something] to be preserved, conserved, looked after".
Eumolpini is a tribe of leaf beetles in the subfamily Eumolpinae.
Loberus is a genus of pleasing fungus beetles in the family Erotylidae. There are about 13 described species in Loberus.
Orthoperus is a genus of minute hooded beetles in the family Corylophidae. There are at least 20 described species in Orthoperus.
