The Strepsiptera are an order of insects with eleven extant families that include about 600 described species. They are endoparasites of other insects, such as bees, wasps, leafhoppers, silverfish, and cockroaches. Females of most species never emerge from the host after entering its body, finally dying inside it. The early-stage larvae do emerge because they must find an unoccupied living host, and the short-lived males must emerge to seek a receptive female in her host. They are believed to be most closely related to beetles, from which they diverged 300–350 million years ago, but do not appear in the fossil record until the mid-Cretaceous around 100 million years ago.
The superfamily Apoidea is a major group within the Hymenoptera, which includes two traditionally recognized lineages, the "sphecoid" wasps, and the bees. Molecular phylogeny demonstrates that the bees arose from within the traditional "Crabronidae", so that grouping is paraphyletic, and this has led to a reclassification to produce monophyletic families.
The superfamily Ichneumonoidea contains one extinct and three extant families, including the two largest families within Hymenoptera: Ichneumonidae and Braconidae. The group is thought to contain as many as 100,000 species, many of which have not yet been described. Like other parasitoid wasps, they were long placed in the "Parasitica", variously considered as an infraorder or an unranked clade, now known to be paraphyletic.
Neoptera is a classification group that includes most orders of the winged insects, specifically those that can flex their wings over their abdomens. This is in contrast with the more basal orders of winged insects, which are unable to flex their wings in this way.
Holometabola, also known as Endopterygota, is a superorder of insects within the infraclass Neoptera that go through distinctive larval, pupal, and adult stages. They undergo a radical metamorphosis, with the larval and adult stages differing considerably in their structure and behaviour. This is called holometabolism, or complete metamorphism.
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 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.
Mecoptera is an order of insects in the superorder Holometabola with about six hundred species in nine families worldwide. Mecopterans are sometimes called scorpionflies after their largest family, Panorpidae, in which the males have enlarged genitals raised over the body that look similar to the stingers of scorpions, and long beaklike rostra. The Bittacidae, or hangingflies, are another prominent family and are known for their elaborate mating rituals, in which females choose mates based on the quality of gift prey offered to them by the males. A smaller group is the snow scorpionflies, family Boreidae, adults of which are sometimes seen walking on snowfields. In contrast, the majority of species in the order inhabit moist environments in tropical locations.
Nannochoristidae is a family of scorpionflies with many unusual traits. It is a tiny, relict family with a single extant genus, Nannochorista, with eight species occurring in New Zealand, southeastern Australia, Tasmania, Argentina and Chile. Due to the group's distinctiveness from other scorpionflies, it is sometimes placed in its own order, the Nannomecoptera. Some studies have placed them as the closest living relatives of fleas. Most mecopteran larvae are eruciform, or shaped like caterpillars. Nannochoristid larvae, however, are elateriform, and have elongated and slender bodies. The larvae are aquatic, which is unique among mecopterans. The larvae are predatory, hunting on the beds of shallow streams, primarily on the larvae of aquatic Diptera like chironomids.
Boreidae, commonly called snow scorpionflies, or in the British Isles, snow fleas are a very small family of scorpionflies, containing only around 30 species, all of which are boreal or high-altitude species in the Northern Hemisphere.
The family Pythidae is a small group of tenebrionoid beetles with no vernacular common name, though recent authors have coined the name dead log bark beetles. There are seven genera, which are largely native to the mid-high latitude regions of the Northern Hemisphere and Australia, with one genus also present in the tropical Americas. The larvae are generally found with decaying vegetation and wood on which they feed, while adults are not associated with the larvae and are generally caught using malaise traps and light traps.
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.
Paraneoptera or Acercaria is a superorder of insects which includes lice, thrips, and hemipterans, the true bugs. It also includes the extinct order Permopsocida, known from fossils dating from the Early Permian to the mid-Cretaceous.
Panorpida or Mecopterida is a proposed superorder of Holometabola. The conjectured monophyly of the Panorpida is historically based on morphological evidence, namely the reduction or loss of the ovipositor and several internal characteristics, including a muscle connecting a pleuron and the first axillary sclerite at the base of the wing, various features of the larval maxilla and labium, and basal fusion of CuP and A1 veins in the hind wings. The monophyly of the Panorpida is supported by recent molecular data.
Eumetabola is an unranked clade of Neoptera. Two large unities known as the Eumetabola and Paurometabola are probably from the adelphotaxa of the Neoptera after exclusion of the Plecoptera. The monophyly of these unities appears to be weakly justified.
Aspidytidae is a family of aquatic beetles of the suborder Adephaga, described in 2002 from specimens in South Africa and China. There are only two known species in the family and these were originally described in the genus Aspidytes, but later the new genus Sinaspidytes was erected for the species found in China. The family can also be referred to by its trivial name cliff water beetles.
Hymenopterida is a superorder of holometabolous (metamorphosing) insects. As originally circumscribed, it included Hymenoptera and the orders in Panorpida. However, more recent studies find Hympenoptera as sister to the other members of Holometabola and the superorder is restricted to Hymenoptera.
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).
Coleopterida is a superorder of insects consisting of the orders Coleoptera and Strepsiptera. It is established as the sister group of Neuropterida based on phylogenetic analysis of DNA sequence data. The grouping is also supported by morphological data.
