Psocid
Guides
Amphigerontia bifasciata
Amphigerontia bifasciata is a small barklouse species in the family Psocidae, characterized by yellowish-black coloration with two dark transverse bands. First described by Latreille in 1799 as Psocus bifasciatus, this species is widely distributed across Europe and has been introduced to North America. It inhabits diverse woody and herbaceous vegetation, feeding on epiphytic microflora.
Amphigerontia contaminata
Amphigerontia contaminata is a barklouse species in the family Psocidae, found across Europe and parts of Asia and North America. Adults are small, soft-bodied insects with either light black or brown coloration. The species has been recorded from numerous tree hosts and shows a broad geographic distribution, though it is uncommon to scarce in parts of its British and Irish range.
Amphigerontia petiolata
common barklouse
Amphigerontia petiolata is a species of barklouse in the family Psocidae. It occurs across North America and Central America. Barklice in this family are typically found on tree bark and foliage, where they feed on microflora.
Belaphotroctes
Belaphotroctes is a genus of small psocids (barklice and booklice) in the family Liposcelididae. Members of this genus are minute, dorsoventrally flattened insects adapted to living in concealed microhabitats such as leaf litter, bark crevices, and stored products. The genus was established by Roesler in 1943 and has been recorded from both the New World (USA, Mexico, Jamaica) and Africa (Angola, Togo).
Blaste opposita
common barklouse
Blaste opposita is a species of barklouse in the family Psocidae, described by Banks in 1907. It is one of the more frequently encountered barklouse species in North America. Barklice are small, soft-bodied insects that typically inhabit bark, foliage, and other surfaces where they feed on organic debris, algae, and lichens. The species is considered harmless to humans and plays a role in nutrient cycling in forest and urban ecosystems.
Blaste osceola
common barklouse
Blaste osceola is a species of barklouse in the family Psocidae, described by Mockford in 1984. It is a member of the order Psocodea, a group of small, soft-bodied insects commonly found on bark, foliage, and other surfaces. The species is known from North America.
Blaste persimilis
common barklouse
Blaste persimilis is a species of barklouse in the family Psocidae, first described by Banks in 1908. It is found in North America, with records from the United States. As a member of Psocidae, it belongs to a group of small, soft-bodied insects commonly known as barklice or booklice that typically inhabit bark, leaf litter, and other organic substrates. The species is part of a diverse genus within a family that includes many common and widespread barklouse species.
Blaste posticata
common barklouse
Blaste posticata is a species of barklouse in the family Psocidae. It belongs to the genus Blaste, which comprises small, winged insects commonly found on tree bark and foliage. The species was described by Nathan Banks in 1905 and is distributed across Central America and North America, including Mexico and the United States.
Blastopsocus lithinus
common barklouse
Blastopsocus lithinus is a species of barklouse in the family Psocidae, first described by Chapman in 1930. It is one of several species in the genus Blastopsocus, which are commonly known as barklice. The species occurs across a broad geographic range spanning temperate and tropical regions of North and Central America. Like other members of Psocidae, it is associated with bark and lichen habitats.
Blastopsocus variabilis
common barklouse
Blastopsocus variabilis is a species of barklouse in the family Psocidae. It has been documented in Central America and North America, with distribution records from the United States and Panama. As a member of Psocidae, it belongs to a group of small, soft-bodied insects commonly found on bark, foliage, and other surfaces. The species was described by Aaron in 1883.
Blastopsocus walshi
Blastopsocus walshi is a species of barklouse in the family Psocidae, described by Mockford in 2002. It belongs to a group of small, soft-bodied insects commonly known as psocids or booklice. The genus Blastopsocus contains multiple species distributed primarily in North America. This species is part of the diverse order Psocodea, which includes both free-living barklice and parasitic lice.
Camelopsocus bactrianus
Camelopsocus bactrianus is a species of barklouse described by Mockford in 1984. It belongs to the family Psocidae, a group of small, soft-bodied insects commonly found on vegetation, bark, and leaf litter. The genus Camelopsocus is part of the tribe Ptyctini, characterized by distinctive wing-rolling behavior and morphology. Very few observations of this species exist in public databases.
Camelopsocus similis
common barklouse
Camelopsocus similis is a species of barklouse in the family Psocidae, described by Mockford in 1965. It belongs to the order Psocodea, a group of small, soft-bodied insects commonly found on vegetation, bark, and leaf litter. The species has been documented in Central America and North America, including Mexico. As with other psocids, it likely inhabits moist microhabitats and feeds on organic detritus, though specific ecological studies are limited.
Cerastipsocus trifasciatus
common barklouse
Cerastipsocus trifasciatus is a barklouse species in the family Psocidae, described by Provancher in 1876. It is widely distributed across the Americas, with records from North America (Canada, USA, Mexico), Central America (Costa Rica, Guatemala, Nicaragua, Panama), and South America (Colombia, Venezuela). As a member of the Psocidae, it inhabits bark and related microhabitats.
Cerastipsocus venosus
Tree Cattle, Common Barklouse
Cerastipsocus venosus is a widespread barklouse species in the family Psocidae, commonly known as "Tree Cattle" due to the herding behavior of its nymphs. It occurs across North America, Central America, and the Caribbean. Both nymphs and adults aggregate on tree bark and foliage, where they feed on lichens and other organic matter. The species is harmless to plants and plays a role in nutrient cycling.
Dorypteryx domestica
cave barklouse
Dorypteryx domestica is a small psocid, commonly known as the cave barklouse, in the family Psyllipsocidae. Originally described as Dolopteryx domestica from Zimbabwe in 1958, it was later transferred to Dorypteryx by Lienhard in 1977. The species has a remarkably broad geographic distribution spanning Africa, Europe, Northern Asia, and North America, and has been recorded from domestic as well as cave habitats.
Ectopsocopsis cryptomeriae
Large-winged Psocid
Ectopsocopsis cryptomeriae is a species of outer barklouse known as the large-winged psocid. It belongs to the family Ectopsocidae and has a remarkably broad geographic distribution spanning six continents. The species was first described by Enderlein in 1907 under the basionym Ectopsocus cryptomeriae. It is one of the more frequently observed psocids, with substantial iNaturalist documentation.
Elipsocus abdominalis
Elipsocus abdominalis is a species of barklouse in the family Elipsocidae. It occurs across much of Europe, with records from Great Britain and Ireland through Scandinavia, central Europe, and the Mediterranean. The species has also been recorded in North America, though these may represent introduced populations. Adults are blackish-orange in coloration and have been observed feeding on a range of deciduous and coniferous trees.
Hyalopsocus striatus
common barklouse
Hyalopsocus striatus is a species of barklouse in the family Psocidae. It is found in North America, with records from the United States and Canada. As a member of the Psocidae, it is part of a group of small, soft-bodied insects commonly known as barklice or booklice, which are typically associated with tree bark, leaf litter, and other decaying organic matter. The species was described by Francis Walker in 1853.
Indiopsocus campestris
common barklouse
Indiopsocus campestris is a species of barklouse in the family Psocidae, originally described by Aaron in 1886. It is found in the Caribbean Sea and North America. Barklice are small, soft-bodied insects that are easily mistaken for planthoppers or tiny moths but possess chewing mouthparts rather than piercing-sucking or siphoning mouthparts.
Indiopsocus ceterus
common barklouse
Indiopsocus ceterus is a species of barklouse in the family Psocidae, first described by Mockford in 1974. It is a small, winged insect that inhabits bark and foliage surfaces. The species is known from the Caribbean Sea region and North America, including Cuba and the United States. It has been documented at blacklight stations, indicating nocturnal activity.
Indiopsocus coquilletti
common barklouse
Indiopsocus coquilletti is a species of barklouse in the family Psocidae. It is found in Central America and North America, including the United States and Mexico. Barklice in this family are commonly encountered on bark, foliage, and other surfaces where they feed on organic debris.
Indiopsocus lacteus
Indiopsocus lacteus is a species of barklouse in the family Psocidae, described by Mockford and Young in 2015. The species name "lacteus" (milky or milk-white) likely refers to its pale coloration. Like other members of the genus Indiopsocus, it belongs to the common barklice, a group of small, soft-bodied insects often found on tree bark, rocks, and other surfaces. The species has been documented in North America, including observations in Kansas.
Indiopsocus lanceolatus
Indiopsocus lanceolatus is a species of barklouse in the family Psocidae, described by Mockford and Young in 2015. The species belongs to the genus Indiopsocus, which comprises common barklice found in various habitats across North America. As a member of Psocodea, it possesses chewing mouthparts and is typically associated with dead plant material, bark, and leaf litter.
Lachesilla arida
Lachesilla arida is a species of barklouse in the family Lachesillidae, described by Chapman in 1930. The species is classified within the order Psocodea, a group of small, often overlooked insects commonly known as barklice or booklice. Records indicate its presence in North America.
Lachesilla pacifica
Lachesilla pacifica is a species of barklouse in the family Lachesillidae, first described by Chapman in 1930. It belongs to the order Psocodea, a group of small, soft-bodied insects commonly known as psocids or booklice. The species has been recorded across a broad geographic range spanning North America, Europe, and parts of Middle America.
Lachesilla sulcata
fateful barklouse
Lachesilla sulcata is a species of barklouse described by García-Aldrete in 1986. It belongs to the family Lachesillidae, a group of small, soft-bodied insects commonly known as barklice or booklice. The species has been documented in both Central America and North America, with confirmed records from Mexico and the United States. As with many psocid species, detailed ecological and behavioral information remains limited.
Lachesilla typhicola
fateful barklouse
Lachesilla typhicola is a species of barklouse in the family Lachesillidae, described by García-Aldrete in 1999. It belongs to the order Psocodea, which includes barklice and booklice. The species epithet 'typhicola' suggests an association with cattails (Typha species). It is known from North America, specifically recorded from the United States.
Liposcelis decolor
booklouse
Liposcelis decolor is a minute stored-product pest psocid (booklouse) of significant economic importance worldwide. It infests stored grains and grain products, causing direct damage through consumption of endosperm and germ, and indirect damage by distributing molds and transmitting disease pathogens. The species exhibits high tolerance to phosphine fumigant, making chemical control difficult, and recovers rapidly from poorly conducted fumigations. It has been extensively studied as prey for biological control agents including the warehouse pirate bug Xylocoris flavipes and predatory mites Cheyletus eruditus and C. malaccensis.
Liposcelis entomophila
booklouse
Liposcelis entomophila is a small psocid species commonly known as a booklouse. It is a significant pest of stored grain products, with documented infestations in wheat and other stored foods. The species exhibits sexual dimorphism in development, with females passing through four nymphal stages and males through three. It has developed notable resistance to phosphine fumigants used in grain storage, with resistant factors of 40- to 80-fold reported in Chinese populations. The species has a broad global distribution spanning six continents.
Liposcelis ornata
booklouse
Liposcelis ornata is a species of booklouse described by Mockford in 1978. It belongs to the family Liposcelididae, a group of small, wingless or weakly winged insects commonly associated with stored products and human habitats. The species has been documented across a broad geographic range spanning Central America, North America, and South America.
Maoripsocus semifuscatus
Maoripsocus semifuscatus is a species of barklouse in the family Caeciliusidae. It was described by Tillyard in 1923 from New Zealand material. The species belongs to a genus endemic to the Australasian region, with records from both New Zealand and Australia.
Mesopsocus immunis
woodland barklouse
Mesopsocus immunis is a barklouse species in the family Mesopsocidae, commonly known as the woodland barklouse. It occurs across Western Europe and Hungary, inhabiting woodland environments where it feeds on lichens, algae, and other organic material on tree bark. The species has been introduced to North America, with records from Canada.
Metylophorus barretti
common barklouse
Metylophorus barretti is a species of barklouse in the family Psocidae. It belongs to a genus of small, soft-bodied insects commonly associated with tree bark and other plant surfaces. The species has been documented in North America and Central America. Like other members of Psocidae, it is likely associated with feeding on microflora such as lichens, algae, and fungal spores.
Metylophorus novaescotiae
Speckled Barklouse
Metylophorus novaescotiae is a species of barklouse in the family Psocidae, commonly known as the Speckled Barklouse. It is one of the most frequently observed barklice in North America, with substantial iNaturalist documentation. The species was originally described by Francis Walker in 1853 under the basionym Psocus novaescotiae. It inhabits wooded environments where it feeds on lichens, algae, and organic debris on tree bark.
Myopsocus antillanus
Myopsocus antillanus is a species of barklouse in the family Myopsocidae, described by Mockford in 1974. The species belongs to a genus characterized by eyes with distinct facets and reduced or absent ocelli. Like other members of Psocodea, it is a small, soft-bodied insect associated with vegetation and decaying organic matter.
Peripsocus madidus
stout barklouse
Peripsocus madidus is a species of stout barklouse described by Hagen in 1861. It is a member of the family Peripsocidae, a group of free-living psocids commonly found on bark and foliage. The species has been documented across North America and Central America. Like other peripsocids, it is likely associated with lichen and algal growth on tree surfaces.
Peripsocus subfasciatus
Peripsocus subfasciatus is a barklouse species in the family Peripsocidae, found across Europe, the Azores, and North and South America. Adults are either black or brown in coloration. The species has been recorded feeding on a diverse range of woody plants including both conifers and broadleaf trees.
Philotarsus arizonicus
Philotarsus arizonicus is a species of barklouse in the family Philotarsidae, described by Mockford in 2007. The species is known from Arizona, USA. As a member of the order Psocodea, it is a small, winged insect associated with tree bark and foliage habitats. The genus Philotarsus is part of the infraorder Philotarsetae, a group of free-living barklice that feed on microflora including lichens, algae, and fungal spores.
Pseudorypteryx mexicana
Pseudorypteryx mexicana is a species of trogiomorphan psocid (barklouse) in the family Psyllipsocidae, described by García-Aldrete in 1984. Members of this family are small, wingless insects typically associated with dark, humid microhabitats. The genus Pseudorypteryx is characterized by reduced wing venation and other troglomorphic adaptations. This species occurs in Mexico and the United States.
Psocini
Psocini is a tribe of barklice within the family Psocidae, established by Hagen in 1865. Members of this tribe are small, soft-bodied insects commonly found on tree bark, foliage, and other surfaces where they feed on microflora. The tribe contains multiple genera and is part of the diverse Psocomorpha suborder. Psocini species are generally recognized by their wing venation patterns and body proportions, though precise boundaries between related tribes require detailed morphological examination.
Psyllipsocidae
Cave Barklice
Psyllipsocidae is a family of small psocid insects commonly known as cave barklice, comprising approximately 7 genera and more than 70 described species. The family belongs to the suborder Trogiomorpha within the order Psocodea. Members of this family have been recorded across multiple biogeographic realms including West Palaearctic, Afrotropical, Australian, Nearctic, Neotropical, and Oriental regions. Some genera, such as Dorypteryx, exhibit notably wide geographic distributions. Several extinct genera are known from Cretaceous amber deposits.
Psyllipsocus decoratus
A small barklouse species in the family Psyllipsocidae, described by Mockford in 2011. Members of this genus are typically found in sheltered microhabitats and are characterized by reduced or absent wings. The species name "decoratus" suggests distinctive ornamental or patterned features.
Pteroxanium kelloggi
Pteroxanium kelloggi is a bark louse species in the family Lepidopsocidae. It has a distinctive brownish-orange coloration with white spots. The species has been recorded from western Europe and Madeira, with additional distribution records from North America, South America, and Australasia. It feeds on a variety of woody plants including ash, cedar, gorse, ivy, larch, oak, pine, and yew, and has also been observed on rhododendrons and decayed wood substrates.
Ptycta
barklice
Ptycta is a genus of barklice (family Psocidae) containing more than 150 described species. The genus was redefined based on the morphology of the male terminalia, specifically the forewing venation where veins Rs+M are fused for a short distance. Species occur across multiple continents including Asia, Australia, Africa, and the Americas. The genus is distinguished from the related Copostigma within the Copostigma–Ptycta complex by this wing venation character.
Ptycta lineata
Ptycta lineata is a barklouse species in the family Psocidae, described by Mockford in 1974. It occurs across the Caribbean, Middle America, and southern North America. Like other members of its genus, it inhabits dead leaf litter and surface vegetation in humid environments. The species is one of approximately 70 described in the genus Ptycta.
Rhyopsocus bentonae
bird nest barklouse
Rhyopsocus bentonae is a barklouse species in the family Psoquillidae, described by Sommerman in 1956. It is classified within the suborder Trogiomorpha and infraorder Atropetae of the order Psocodea. The species is distributed across Central and North America. As a member of Psoquillidae, it is associated with bird nest habitats.
Rhyopsocus celtis
Rhyopsocus celtis is a species of psocid (barklouse) in the family Psoquillidae, described by Mockford in 2016. The specific epithet "celtis" indicates its association with hackberry trees (Celtis spp.), which serve as its host. The species belongs to a small genus of psocids that inhabit dead or dying woody vegetation.
Rhyopsocus quercus
Rhyopsocus quercus is a species of psocid described by Mockford in 2016, belonging to the family Psoquillidae. The specific epithet 'quercus' suggests an association with oak (Quercus), though the nature of this relationship remains to be fully documented. As a member of the order Psocodea, this species is part of a group of small, often overlooked insects that occur in diverse terrestrial habitats.
Soa flaviterminata
Soa flaviterminata is a species of booklouse in the family Lepidopsocidae, described by Enderlein in 1906. It belongs to the order Psocodea, a group of small, often overlooked insects that includes both parasitic lice and free-living barklice and booklice. The species is placed in the suborder Trogiomorpha, a lineage characterized by reduced wing venation and other derived features. Like other members of its family, it likely inhabits sheltered microhabitats in tropical or subtropical environments.
Speleketor flocki
Speleketor flocki is a species of cave-dwelling psocopteran insect in the family Prionoglarididae, described by Gurney in 1943. It belongs to the suborder Trogiomorpha, a group of psocids adapted to dark, humid environments. The genus Speleketor is specialized for cave habitats, with reduced or absent eyes and elongated appendages typical of troglobitic insects.
Stenocaecilius casarum
lizard barklouse
Stenocaecilius casarum is a species of lizard barklouse in the family Caeciliusidae. It has one of the widest geographic distributions of any barklouse species, occurring across six continents and numerous oceanic islands. The species was first described by Badonnel in 1931. Its common name refers to its lizard-like appearance and movement patterns.
Trichadenotecnum desolatum
Trichadenotecnum desolatum is a species of barklouse in the family Psocidae, originally described by Chapman in 1930 as Psocus desolatus. It belongs to the genus Trichadenotecnum, a group of small, winged psocids commonly found on tree bark and foliage. The species is known from the southern United States and Mexico. Like other members of its family, it likely inhabits woody vegetation and feeds on microflora.
Trichadenotecnum majus
common barklouse
Trichadenotecnum majus is a species of common barklouse in the family Psocidae. It has been recorded across Europe, Northern Asia (excluding China), and North America. As a member of the barklice, it inhabits environments where it feeds on organic debris such as lichens, algae, and dead plant material on tree bark and rocks.
Trichadenotecnum merum
common barklouse
Trichadenotecnum merum is a uniparental barklouse species described in 1983 as part of the Trichadenotecnum alexanderae species complex. It reproduces exclusively through obligatory parthenogenesis (thelytoky), with populations composed entirely of females. The species was established through mating tests, life history observations, and morphological analysis across the geographic range of the species complex. As a member of the family Psocidae, it belongs to a group commonly known as common barklice.
Trichadenotecnum pardus
Trichadenotecnum pardus is a species of barklouse in the family Psocidae, first described by Badonnel in 1955. It belongs to a genus of common barklice that are frequently encountered on tree bark and foliage. The species has been recorded across multiple continents including North America, South America, Africa, and Asia, suggesting either a wide natural distribution or potential human-mediated dispersal. Like other psocids, it is likely associated with decaying organic matter and microhabitats on vegetation.
Trichadenotecnum slossonae
common barklouse
Trichadenotecnum slossonae is a species of barklouse in the family Psocidae. It was first described by Banks in 1903. The species occurs in Central America and North America. Like other members of its genus, it is likely associated with bark and lichen habitats, though specific ecological details remain limited.
Trichopsocus clarus
Trichopsocus clarus is a small psocid (barklouse) species in the family Trichopsocidae. It is distinguished by its yellow to orange coloration. The species has a remarkably broad distribution, occurring across Europe from Scandinavia to the Mediterranean, as well as on Atlantic islands and in Australia and New Zealand. It inhabits foliage of various trees.
Trogium pulsatorium
larger pale booklouse, deathwatch, common booklouse, grain psocid
Trogium pulsatorium is a granary booklouse in the family Trogiidae with a near-cosmopolitan distribution spanning six continents. It inhabits stored grain facilities, warehouses, and human dwellings where it feeds on dry organic matter. The species is notable for its association with stored products and its historical confusion with true deathwatch beetles due to shared common names.
Valenzuela burmeisteri
Valenzuela burmeisteri is a species of barklouse in the family Caeciliusidae. It is a small, winged insect with yellowish-black coloration. The species has a broad distribution across Europe, including the British Isles, and extends into the Near East. It has been recorded from numerous European countries and island groups including the Azores, Madeira, and Canary Islands.
Valenzuela flavidus
yellow barklouse
Valenzuela flavidus is a barklouse species in the family Caeciliusidae, originally described as Psocus flavidus by Stephens in 1836 and later transferred to Valenzuela by Navás in 1924. The species exhibits complex population structure with both sexual and asexual reproduction modes: European populations are all-female and triploid, reproducing via parthenogenesis, while North American populations contain males and appear to be diploid with sexual reproduction. This cryptic diversity within the species complex has been confirmed through genomic studies.
Valenzuela perplexus
lizard barklouse
Valenzuela perplexus is a species of lizard barklouse in the family Caeciliusidae, a group of small, winged insects commonly associated with bark and foliage habitats. The species was described by Chapman in 1930 and is distributed across Central America and North America, with records from Mexico. Like other members of the genus Valenzuela, it is likely associated with dead leaf and bark microhabitats. The specific epithet "perplexus" suggests taxonomic complexity in its original description.
Valenzuela totonacus
Valenzuela totonacus is a species of barklouse in the family Caeciliusidae, described by Mockford in 1966. The species belongs to the order Psocodea, a group of small, often overlooked insects commonly known as barklice or booklice. It has been recorded from the southern United States through Mexico to Guatemala.