Louse is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been recognized as an order, infraorder, or a parvorder, as a result of developments in phylogenetic research.
The Mallophaga are a possibly paraphyletic section of lice, known as chewing lice, biting lice, or bird lice, containing more than 3000 species. These lice are external parasites that feed mainly on birds, although some species also feed on mammals. They infest both domestic and wild mammals and birds, and cause considerable irritation to their hosts. They have paurometabolis or incomplete metamorphosis.
The genus Haematomyzus includes three species of lice that differ so markedly from all other lice that the genus is placed in its own family Haematomyzidae, itself monotypic within the superfamily Rhynchophthirina. These unusual lice are ectoparasites of elephants and warthogs. Their mouthparts are elongated to form a drill-like structure that allows them to penetrate the thick skin of their host.
The calandra lark or European calandra-lark breeds in warm temperate countries around the Mediterranean and eastwards through Turkey into northern Iran and southern Russia. It is replaced further east by its relative, the bimaculated lark.
Psocoptera are a paraphyletic group of insects that are commonly known as booklice, barklice or barkflies. The name Psocoptera has been replaced with Psocodea in recent literature, with the inclusion of the former order Phthiraptera into Psocodea.
A bird louse is any chewing louse of order Phthiraptera which parasitizes warm-blooded animals, especially birds. Bird lice may feed on feathers, skin, or blood. They have no wings, and their biting mouth parts distinguish them from true lice, which suck blood.
Menoponidae is a monophyletic family of lice in the superfamily of chewing lice, Amblycera, often referred to as the chicken body louse family. They are ectoparasites of a wide range of birds including chickens, which makes them important to understand for veterinary science and for human health. However, Menoponidae are not exclusive to poultry and are common parasites for migratory birds, with more and more species being discovered every year.
Psocodea is a taxonomic group of insects comprising the bark lice, book lice and parasitic lice. It was formerly considered a superorder, but is now generally considered by entomologists as an order. Despite the greatly differing appearance of parasitic lice (Phthiraptera), they are believed to have evolved from within the former order Psocoptera, which contained the bark lice and book lice, now found to be paraphyletic. They are often regarded as the most primitive of the hemipteroids. Psocodea contains around 11,000 species, divided among four suborders and more than 70 families. They range in size from 1–10 millimetres (0.04–0.4 in) in length.
Feather holes often characteristically occur on wing and tail feathers of some small-bodied species of passerines. In the case of barn swallows, it was suggested that the holes were feeding traces of avian lice, either Machaerilaemus malleus and/or Myrsidea rustica.
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.
Menacanthus is a genus of chewing lice which parasitise birds. The taxonomy of this genus is highly uncertain. Most taxonomies have given this genus as having over a hundred species, but recent studies have synonymised dozens of species and found other names to be invalid. Some Menacanthus species remain to be discovered, or are synonymised in error. Menacanthus lice feed on the blood of a wide variety of birds, including chickens, by piercing the quills of feathers and gnawing the epidermis. In doing so, they can spread disease and lower egg production. In Menacanthus stramineus, eggs are incubated for four or five days, each of the three nymphal stages lasts for about three days, and adult life for about twelve days. Females produce as many as four eggs in a day, averaging 1.6 eggs a day, with egg production peaking 5–6 days after reaching adulthood. On sparrows, Menacanthus lice are particularly common, and are found in many different niches, consuming blood and feathers.
Brueelia is a genus of bird lice in the family Philopteridae that infest Passerine (perching) birds. Lice in Brueelia are usually host specific, with more than 85% of described species each found on a single host bird species. Over 300 species of Brueelia have been described, and many more specimens that are presumed to belong to Brueelia are awaiting description and naming.
Ricinus is a genus of chewing lice which parasitise birds. It is the largest-bodied genus of chewing lice found parasitizing Passeriformes.
Ricinus vaderi is a species of chewing lice which parasitises the calandra lark in Azerbaijan. It is a member of Ricinus, the largest genus of chewing lice found parasitizing Passeriformes.
Meromenopon is a genus of chewing lice which parasitise birds. The species Meromenopon meropsis is a parasite of bee-eaters.
Strigiphilus is a genus of chewing louse in the suborder Ischnocera. It was circumscribed in 1910 by Eric Mjöberg.
Colpocephalum is a genus of chewing louse. Christian Ludwig Nitzsch named the genus in 1818. The Plenary Powers of the International Commission on Zoological Nomenclature selected Colpocephalum zebraBurmeister, 1838 as its type species in the 1950s. There are approximately 135 species in this genus, and they are ectoparasites of birds in at least a dozen different orders.
Rallicola is a genus of chewing louse. It is an ectoparasite of rails and other birds. It was named by Thomas Harvey Johnston and Launcelot Harrison in 1911. There are two subgenera aside from the nominotypical subgenus: Aptericola, whose species are found on kiwi birds, and Huiacola, a monospecific subgenus consisting of Rallicola extinctus, once found on the huia.
Apterygon is a genus of louse. It is endemic to New Zealand and is an ectoparasite of kiwi birds (Apteryx). Theresa Clay circumscribed the genus in 1961. In 1947, she had referred to this genus as "New Genus D", but it was not formally named as she needed to confirm the host of her specimen as well as additional material.
Harrison's rule is an observation in evolutionary biology by Launcelot Harrison which states that in comparisons across closely related species, host and parasite body sizes tend to covary positively.
