In taxonomy, a grouping is paraphyletic if it consists of the grouping's last common ancestor and most of its descendants, but excludes a few monophyletic subgroups. The grouping is said to be paraphyletic with respect to the excluded subgroups. In contrast, a monophyletic grouping includes a common ancestor and all of its descendants. The terms are commonly used in phylogenetics and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic.
Hemiptera is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from 1 mm (0.04 in) to around 15 cm (6 in), and share a common arrangement of piercing-sucking mouthparts. The name "true bugs" is often limited to the suborder Heteroptera.
The Heteroptera are a group of about 40,000 species of insects in the order Hemiptera. They are sometimes called "true bugs", though that name more commonly refers to the Hemiptera as a whole. "Typical bugs" might be used as a more unequivocal alternative, since the heteropterans are most consistently and universally termed "bugs" among the Hemiptera. "Heteroptera" is Greek for "different wings": most species have forewings with both membranous and hardened portions ; members of the primitive sub-group Enicocephalomorpha have completely membranous wings.
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.
The Reduviidae is a large cosmopolitan family of the order Hemiptera. Among the Hemiptera and together with the Nabidae almost all species are terrestrial ambush predators; most other predatory Hemiptera are aquatic. The main examples of nonpredatory Reduviidae are some blood-sucking ectoparasites in the subfamily Triatominae. Though spectacular exceptions are known, most members of the family are fairly easily recognizable; they have a relatively narrow neck, sturdy build, and a formidable curved proboscis. Large specimens should be handled with caution, if at all, because they sometimes defend themselves with a very painful stab from the proboscis.
Cirrina or Cirrata is a suborder and one of the two main divisions of octopuses. Cirrate octopuses have a small, internal shell and two fins on their head, while their sister suborder Incirrina has neither. The fins of cirrate octopods are associated with a unique cartilage-like shell in a shell sac. In cross-section, the fins have distinct proximal and distal regions, both of which are covered by a thin surface sheath of muscle.
A leafhopper is the common name for any species from the family Cicadellidae. These minute insects, colloquially known as hoppers, are plant feeders that suck plant sap from grass, shrubs, or trees. Their hind legs are modified for jumping, and are covered with hairs that facilitate the spreading of a secretion over their bodies that acts as a water repellent and carrier of pheromones. They undergo a partial metamorphosis, and have various host associations, varying from very generalized to very specific. Some species have a cosmopolitan distribution, or occur throughout the temperate and tropical regions. Some are pests or vectors of plant viruses and phytoplasmas. The family is distributed all over the world, and constitutes the second-largest hemipteran family, with at least 20,000 described species.
The Peloridiidae or moss bugs are a family of true bugs, comprising eighteen genera and thirty-four species. They are small, ranging in length from 2 to 4 mm, rarely seen, peculiarly lumpy, flattened bugs found in Patagonia, New Zealand, eastern Australia, Lord Howe Island, and New Caledonia. Peloridiids are found amongst mosses and liverworts, commonly in association with southern beech forests. They have become known as moss bugs for their habit of feeding on mosses. Almost all Peloridiidae species are flightless, except one. Their present distribution suggests they have existed since before the breakup of Gondwana. They are the only living members of the suborder Coleorrhyncha, which first appeared in the Upper Permian, over 250 million years ago.
The Auchenorrhyncha suborder of the Hemiptera contains most of the familiar members of what was called the "Homoptera" – groups such as cicadas, leafhoppers, treehoppers, planthoppers, and spittlebugs. The aphids and scale insects are the other well-known "Homoptera", and they are in the suborder Sternorrhyncha.
Pancrustacea is the clade that comprises all crustaceans, including hexapods. This grouping is contrary to the Atelocerata hypothesis, in which Hexapoda and Myriapoda are sister taxa, and Crustacea are only more distantly related. As of 2010, the Pancrustacea taxon was considered well accepted, with most studies recovering Hexapoda within Crustacea. The clade has also been called Tetraconata, referring to having four cone cells in the ommatidia. This name is preferred by some scientists as a means of avoiding confusion with the use of "pan-" to indicate a clade that includes a crown group and all of its stem group representatives.
The name Prosorrhyncha is a name for a suborder of Hemiptera, comprising a grouping of the traditional taxon "Heteroptera" plus its sister taxon, the family Peloridiidae. There is no agreement on the status of this taxon, as there are two competing classifications regarding this branch of the Hemiptera; while some hemipterists follow this classification, it has by no means been accepted universally. See the Heteroptera article for the detailed discussion, and a comparison of the two taxoboxes.
The Sternorrhyncha suborder of the Hemiptera contains the aphids, whiteflies, and scale insects, groups which were traditionally included in the now-obsolete order "Homoptera". "Sternorrhyncha" refers to the rearward position of the mouthparts relative to the head.
The Emesinae, or thread-legged bugs, are a subfamily of the Reduviidae. They are conspicuously different from the other reduviids by their very slender body form. They are stalking, predatory insects that can be collected on palm fronds, cliffs, spider webbing, or near lights at night. They walk on their mid and hind legs; the front pair is raptorial. Some groups specialize on spiders. Very little is known about emesines except that many species are found in the tropics. Pedro Wygodzinsky wrote the most recent revision of this group.
28S ribosomal RNA is the structural ribosomal RNA (rRNA) for the large subunit (LSU) of eukaryotic cytoplasmic ribosomes, and thus one of the basic components of all eukaryotic cells. It has a size of 25S in plants and 28S in mammals, hence the alias of 25S–28S rRNA.
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.
Coleorrhyncha or Peloridiomorpha, also known as moss bugs or beetle bugs, are a suborder of Hemiptera and represent an ancient lineage of moss-feeding insects. They show some similarities to the Heteroptera but have been considered distinct. It has a single extant family, the Peloridiidae. They are 2 to 5 millimetres in length, and feed on moss and liverworts. They have wings in some species which are reduced in others but all species are flightless and live in damp moss habitats and are associated with the distribution of Nothofagus trees in Australia, New Zealand, New Caledonia, and South America, which all were formerly part of the supercontinent Gondwana.
Furcaspidina is a subtribe of armored scale insects, traditionally regarded as part of the Aspidiotini. While the subtribe Furcaspidina was not mentioned in Takagi's 2002 study, the Aspidiotini were not deemed as problematical as the Diaspidini and Lepidosaphidini. In 2006, Williams reduced the Furcaspidina to a single genus, with about twenty-eight species. Andersen in 2009 suggested that the Furcaspidina belonged in an expanded subfamily of Diaspidinae; however, additional analysis suggests that the furcaspids are better placed in a distinct, but laterally equivalent subfamily to the Diaspidinae, possibly together with the gymnaspids which Borchsenius placed in the Aspidiotinae subfamily.
Gymnaspidina is a subtribe of armored scale insects. Takagi (2002) does not mention the Gymnaspidina, but in 2006 Morse and Normark still placed Gymnaspis aechmeae within the Parlatoriini tribe. Anderson (2010) found Gymnaspidina to be radically polyphyletic and suggested that the gymnaspids and the furcaspids might be placed in a distinct, but laterally equivalent subfamily to the Diaspidinae, rather than in the Aspidiotinae.
Kuwanaspidina is a subtribe of armored scale insects. They feed on bamboo.
Phylloxeridae is a small family of plant-parasitic hemipterans closely related to aphids with only 75 described species. This group comprises two subfamilies and 11 genera with one that is fossil. The genus type is Phylloxera. The Phylloxeridae species are usually called phylloxerans or phylloxerids.
