Introduced-species
Guides
Pentarthrum huttoni
Pentarthrum huttoni is a wood-boring weevil in the family Curculionidae. It has been documented causing damage to historic wooden structures, notably 18th-century softwood coffins in Vienna. The species exhibits a primarily Nearctic distribution but has established populations in several European countries.
Perittia herrichiella
Perittia herrichiella is a small moth in the family Elachistidae, characterized by its leaf-mining larval stage on honeysuckles and related plants. The species has a trans-Palearctic distribution across Europe and has been introduced to North America, where it is established in the northeastern United States and adjacent Canada. Adults are active in summer, while larvae feed internally in leaves of host plants.
Perizoma
Rivulets, Carpets
Perizoma is a genus of geometer moths comprising over 150 species, with a predominantly Northern Hemisphere distribution. It serves as the type genus of the tribe Perizomini within the subfamily Larentiinae. Species are commonly known as rivulets or carpets. The genus was established by Jacob Hübner in 1825 and has undergone taxonomic revision, with some related genera (Gagitodes, Martania, Mesotype) now included by some authorities. Several species have been introduced outside their native ranges, including P. alchemillata in Newfoundland.
Phacophallus pallidipennis
Pale-winged Rove Beetle
A rove beetle (Staphylinidae) with broad native distribution across Asia and introduced populations in Europe, North America, Australia, and various oceanic islands. The species has been transported widely through human activity, with established populations documented from the Canary Islands to Hawaii.
Phalacrus
Phalacrus is a genus of small beetles in the family Phalacridae, established by Paykull in 1800. Members of this genus are part of the superfamily Cucujoidea. The genus includes species such as Phalacrus uniformis, which has been introduced from Australia to New Zealand. Phalacrus beetles are generally associated with fungal habitats.
Phelister haemorrhous
clown beetle
Phelister haemorrhous is a species of clown beetle in the family Histeridae, first described by Marseul in 1854. The species has a notably broad distribution spanning multiple continents, including native ranges in the Americas and an apparent introduced population in Italy. As a member of the Histeridae, it belongs to a family of beetles commonly associated with decomposing organic matter.
Phidippus audax
bold jumping spider, daring jumping spider, bold jumper
Phidippus audax is a common North American jumping spider recognized by its iridescent green chelicerae and distinctive abdominal patterning. Adults range from 6–15 mm in body length, with females larger than males. The species is active during daylight hours, using exceptional stereoscopic vision to stalk and pounce on prey rather than building capture webs. It has been introduced to Hawaii, the Nicobar Islands, the Azores, and the Netherlands.
Philodromus dispar
Eurasian Running Crab Spider
Philodromus dispar is a small running crab spider native to Eurasia that has been introduced to North America. It is an active hunter that does not build webs, instead ambushing prey on vegetation. The species exhibits pronounced sexual dimorphism in coloration: males are shiny black or dark brown with white margins, while females are highly variable in size and color. Its attachment ability depends on ambient humidity, with optimal adhesion at intermediate humidity levels.
Philonthus carbonarius
Philonthus carbonarius is a rove beetle (family Staphylinidae) native to the Palearctic region, introduced to North America. It is a predatory species associated with decaying organic matter, including carrion and fungi. The species was first documented in North America in the late 20th century and has since established populations across Canada and the United States.
Philonthus concinnus
Philonthus concinnus is a rove beetle in the family Staphylinidae, first described by Gravenhorst in 1802. The genus Philonthus is a large and diverse group of predatory rove beetles, though specific ecological details for P. concinnus remain poorly documented in available sources. The species has a broad distribution spanning Europe, North Africa, the Middle East, Central Asia, and parts of East Asia, and has been introduced to North America where it is now established in Canada and the United States. Like other members of its genus, it is presumed to be predatory, but direct observations of its biology are sparse.
Philonthus debilis
Philonthus debilis is a rove beetle in the family Staphylinidae. As a member of the genus Philonthus, it belongs to a diverse group of predatory beetles commonly associated with carrion, dung, and other decomposing organic matter. The species has been recorded across a broad geographic range spanning the Palearctic region and has been introduced to North America. Like other Philonthus species, it likely plays a role in carrion succession as a predator on fly larvae and other small insects.
Philonthus hepaticus
Philonthus hepaticus is a large rove beetle in the family Staphylinidae, first described by Erichson in 1840. It is one of the larger species within the genus Philonthus. The species has a broad distribution across the Americas, with records from Canada through Argentina and the Caribbean, and has been introduced to Australia and New Zealand. In Canada, it was first documented in British Columbia, with a second record from New Brunswick representing the first eastern Canadian occurrence.
Philonthus sanguinolentus
A medium-sized rove beetle in the genus Philonthus, characterized by dark coloration with reddish or blood-red markings that give the species its name. Like other members of Staphylinidae, it exhibits the family's distinctive short elytra that leave much of the abdomen exposed. The species has a Palearctic native distribution but has been introduced to North America, where it is established in the Pacific Northwest and parts of Canada.
Philonthus umbratilis
Philonthus umbratilis is a rove beetle in the family Staphylinidae, originally described from Europe and now widely distributed across the Northern Hemisphere. The species has been introduced to North America, Australia, and New Zealand. Like other members of the genus Philonthus, it is a predatory beetle associated with decaying organic matter. The species exhibits the characteristic shortened elytra and flexible abdomen typical of staphylinid beetles.
Philonthus varians
A rove beetle in the family Staphylinidae with a wide native distribution across the Palearctic region and established introduced populations in North America and elsewhere. As a member of the large genus Philonthus, it is one of many similar-looking predatory rove beetles. The species has been documented in carrion habitats alongside other decomposer-associated beetles.
Philoscia muscorum
Common Striped Woodlouse, Fast Woodlouse
Philoscia muscorum is a common European woodlouse notable for its rapid movement and distinctive appearance. It exhibits a unique life history strategy called year class splitting, where individuals from the same reproductive cohort diverge into two developmental pathways: faster-growing individuals mature and reproduce in their first year, while slower-growing individuals delay maturation until their second year. This species has successfully established introduced populations in eastern North America, including New England, the mid-Atlantic states, and the Pacific Northwest.
Phloeocharis
Phloeocharis is a genus of rove beetles in the subfamily Phloeocharinae. Species in this genus are saproxylic, living under tree bark in association with bark beetle communities. The genus is native to the Palearctic region, with at least one species, Phloeocharis subtilissima, introduced to North America via port cities.
Phloeocharis subtilissima
Phloeocharis subtilissima is a small rove beetle (Staphylinidae: Phloeocharinae) native to the Palearctic region. It was first documented in North America in 2004 from Point Pleasant Park, Halifax, Nova Scotia, representing an introduction via maritime shipping. The species belongs to a subfamily associated with decaying plant matter and fungal habitats.
Phoebis agarithe
Large Orange Sulphur, Orange Giant Sulphur
A medium to large sulphur butterfly of the family Pieridae, ranging from Peru through Central America and the Caribbean to the southern United States. Adults display bright orange upperwings with variable dark marginal markings. The species exhibits strong flight and is frequently observed visiting flowers in open, disturbed habitats. It has been introduced to Hawaii and occasionally strays northward well beyond its core range.
Pholcus opilionoides
Opilion-like Cellar Spider
Pholcus opilionoides is a cellar spider species in the family Pholcidae, named for its resemblance to harvestmen (Opiliones) due to its exceptionally long, sprawling legs. The species is native to Europe, Egypt, the Caucasus, and possibly Iran, and has been introduced to North America. Adults are small-bodied with a body length of 3-5 mm but appear larger due to their elongated legs. It is frequently confused with the more widespread Pholcus phalangioides and the similar Pholcus manueli, requiring careful examination for accurate identification.
Phradonoma nobile
A dermestid beetle in the family Dermestidae, with a broad distribution spanning the Mediterranean region, North Africa, the Middle East, Central Asia, and introduced populations in Europe, the United States, and Australia. The species has been documented in arid and semi-arid habitats.
Phycitodes mucidella
White-edged Phycitodes Moth
Phycitodes mucidella is a small pyralid moth known as the White-edged Phycitodes Moth. It belongs to the subfamily Phycitinae, a group commonly referred to as knot-horn moths due to their elongated labial palps. The species is widespread across Europe and has been introduced to North America. It is frequently recorded and relatively well-documented for a pyralid moth of its size.
Phyllaphis fagi
Woolly Beech Aphid
Phyllaphis fagi, the woolly beech aphid, is a small sap-sucking insect that lives exclusively on beech trees (Fagus species). It produces dense white to bluish-white wax threads that give colonies a distinctive woolly appearance. The species has a complex life cycle involving both winged and wingless forms, with up to ten generations per year in favorable conditions. Native to Europe, it has been introduced to several other regions including North America, Australia, and New Zealand, where it can become a significant pest in beech forests and nurseries.
Phyllocnistis vitegenella
Phyllocnistis vitegenella is a small moth in the family Gracillariidae, native to North America, with established populations in Europe since the 1990s. The larvae are leaf miners that feed on grape species, including both native Vitis and cultivated Vitis vinifera, and have become recognized as a pest of commercial vineyards. The species was first described by Clemens in 1859.
Phyllonorycter emberizaepenella
Large Midget
A small leaf-mining moth in the family Gracillariidae with a wingspan of 9–10 mm. It reproduces exclusively by thelytokous parthenogenesis, with no males known to exist. Females nevertheless display diurnal calling behavior and produce sex pheromone compounds, despite the absence of mate attraction. The species is widespread across Europe and has been introduced to North America.
Phylus coryli
hazel plant bug
Phylus coryli is a small plant bug in the family Miridae, commonly known as the hazel plant bug. It is native to Europe, where it is widespread including the British Isles, but absent from parts of the southern Mediterranean. The species has been introduced to North America. It is a specialist feeder on hazel (Corylus avellana).
Phymatodes testaceus
tanbark borer, violet tanbark beetle
Phymatodes testaceus is a transpalearctic polymorphic longhorn beetle in the subfamily Cerambycinae. Adults range from 6–16 mm in length. The species exhibits significant color variation, with some individuals showing violet or metallic reflections that contribute to the common name 'violet tanbark beetle.'
Physocyclus
cellar spiders
Physocyclus is a genus of cellar spiders (family Pholcidae) established by Eugène Louis Simon in 1893. The genus comprises 38 recognized species distributed across multiple continents, with the highest diversity in Mexico. Two distinct species groups are recognized: the globosus group (11 species) and the dugesi group (21 species), distinguished by morphological and biogeographic patterns. The type species, P. globosus, has been widely introduced globally through human activity.
Physocyclus globosus
short-bodied cellar spider
Physocyclus globosus, commonly known as the short-bodied cellar spider, is a small pholcid spider with a cosmopolitan distribution. It is frequently found in anthropogenic habitats including buildings and caves across tropical and subtropical regions, and has been introduced to numerous temperate areas worldwide. The species is characterized by a compact, globose abdomen and distinctive dark dorsal markings. It belongs to the globosus species group within its genus, which exhibits a biogeographical distribution pattern in the Mesoamerican and Mexican Mountain biotic components.
Phytocoris varipes
long-legged plant bug
Phytocoris varipes is a plant bug in the family Miridae, characterized by pinkish-brown to red-brown coloration with longitudinal markings on the upper surface. Adults and nymphs inhabit herbaceous plants and grasses, feeding primarily on flowers and immature fruits. The species has a broad distribution across Europe, extending east to the Caucasus and Iran, with an introduced population in Oregon, USA. Adults are active from June through October, with mating and oviposition occurring in mid-summer.
Picromerus bidens
spiny shieldbug, spiked shieldbug
Picromerus bidens is a predatory shield bug in the family Pentatomidae, notable for its large size and distinctive spiny pronotal projections. It is univoltine, with summer dormancy (aestivation) ensuring synchronization of its life cycle with seasonal conditions. The species is native to the Palaearctic region but has been introduced to North America, where it has established populations. Both adults and nymphs are predatory, feeding primarily on insect larvae, and the species has been investigated as a potential biological control agent.
Pieris rapae
small white, cabbage white, cabbage butterfly, small cabbage white, imported cabbageworm (larval stage), white butterfly (New Zealand)
Pieris rapae is a small to medium-sized butterfly in the family Pieridae, native to Europe and Asia and introduced to North America, Australia, New Zealand, and Hawaii. Adults are white with black wing markings; females bear two additional black spots on the forewings. The species is a significant agricultural pest in its larval stage, known as the imported cabbageworm, feeding on cruciferous crops. It has been extensively studied for its responses to climate change, with long-term data showing progressively earlier spring emergence in North America.
Placusa tachyporoides
Placusa tachyporoides is a rove beetle (Staphylinidae: Aleocharinae) with a broad native distribution across the Palearctic, ranging from Europe and Russia through East Asia to the Himalayas. The species has been introduced to North America, with established populations in Canada and the northern United States. It belongs to the tribe Placusini, a group of small to minute aleocharines often associated with decaying organic matter and fungal substrates.
Plagiodera
willow leaf beetles
Plagiodera is a genus of leaf beetles in the subfamily Chrysomelinae, containing approximately six recognized species distributed across the Holarctic region. The genus is best known for Plagiodera versicolora, commonly called the imported willow leaf beetle, which has been introduced to North America from Europe and is a significant pest of willow and poplar species. Members of this genus are specialized herbivores of Salicaceae, with well-documented chemical ecology and host-plant interactions.
Plagiodera versicolora
Willow Leaf Beetle, Imported Willow Leaf Beetle
Plagiodera versicolora is a small leaf beetle in the subfamily Chrysomelinae, commonly known as the willow leaf beetle or imported willow leaf beetle. Native to Europe and the Mediterranean region, it has been introduced to North America and occurs in parts of Asia. The species is a specialist herbivore on Salicaceae, feeding on willow and poplar leaves throughout its life cycle. Adults overwinter in protected locations and become active in spring, with multiple generations developing through summer. The species has been extensively studied for its chemosensory biology, host plant interactions, and as a model for understanding insect-plant coevolution.
Platnickina tincta
False Pirate Spider
Platnickina tincta is a small tangle web spider (family Theridiidae) with a Holarctic distribution, native to Europe and northern Asia and introduced to North America. It is the type species of the genus Platnickina, originally described from Paris, France. The species is commonly known as the False Pirate Spider.
Platyedra subcinerea
cotton stem moth, mallow groundling
Platyedra subcinerea is a small gelechiid moth native to Europe, now established as an introduced species in North America (New England, California) and New Zealand. It inhabits wet meadows, marshes, and gardens. The species is known by two common names: cotton stem moth and mallow groundling.
Platystethus degener
spiny-legged rove beetle
Platystethus degener is a species of rove beetle in the family Staphylinidae, characterized by spiny legs. It is native to the Palearctic region, with established introduced populations in North America. The species was first described by Mulsant & Rey in 1878. Like other members of the genus Platystethus, it belongs to the subfamily Oxytelinae, a group known for their compact body form and association with decaying organic matter.
Platystethus spiculus
Platystethus spiculus is a small rove beetle (Staphylinidae) first described from South America in 1840. The species has established an exceptionally broad distribution across the Neotropics and has been introduced to the Galápagos Islands and Tahiti. Its spread to oceanic islands suggests human-mediated dispersal, likely through agricultural or horticultural trade. The species belongs to the subfamily Oxytelinae, whose members are often associated with decaying organic matter and moist microhabitats.
Pleistodontes
A genus of fig wasps (Agaonidae) native to Australia and New Guinea, with one species (P. claviger) from Java. Species in this genus are pollinators of Ficus section Malvanthera within subgenus Urostigma. The genus contains approximately 25 described species, with taxonomic revision work indicating some species boundaries remain under investigation.
Poecilocrypticus formicophilus
Adventive Ant-loving Teneb
Poecilocrypticus formicophilus is a small tenebrionid beetle native to Europe, where it has been recorded in Belgium. The species has been introduced to North America and is now established across the conterminous United States. Its common name reflects its association with ant colonies, a relationship characteristic of the genus. The species is frequently documented on iNaturalist, suggesting it is readily encountered by observers.
Polites sabuleti
Sandhill Skipper, Saltgrass Skipper
Polites sabuleti is a small grassland skipper butterfly in the family Hesperiidae, native to western North America from southern British Columbia to Baja California and east to the Rocky Mountains. It has been introduced to Hawaii. The species is notable for its association with weedy grasses including Bermuda grass (Cynodon dactylon), and has experienced significant population declines in parts of its range, particularly in California's Sierra Valley.
Pollenia griseotomentosa
cluster fly
Pollenia griseotomentosa is a Palaearctic cluster fly and the smallest British species in the genus Pollenia, measuring 4.5–8.0 mm in body length. It is distinguished from congeners by specific morphological characters including lack of pale wing tuft, yellow to pale brown posterior thoracic spiracle lappets, dark palpi and basicosta, and characteristic bristle patterns. Like other cluster flies, adults overwinter in sheltered locations including buildings, where they aggregate in large numbers and may become nuisance pests. The species has been introduced to North America, with records from Canada and the northeastern United States.
Pollenia labialis
cluster fly
Pollenia labialis is a species of cluster fly in the family Polleniidae. It is one of several Pollenia species introduced to North America from Europe, likely arriving in the 1950s or 1960s. Like other cluster flies, it is associated with earthworms as larval hosts. The species is distinguished from congeners by microscopic characters including the number, position, and length of setae on various body parts. It is considered a nuisance pest when adults enter buildings to overwinter.
Pollenia rudis
common cluster fly, attic fly, loft fly, buckwheat fly
Pollenia rudis, the common cluster fly, is a medium-sized blow fly in the family Polleniidae. Adults are notable nuisance pests of buildings, overwintering in attics and wall voids in large aggregations during cold months. The species is an obligate parasite of earthworms in its larval stages, with well-documented host specificity to certain lumbricid species. Native to Europe, it has been introduced to North America and New Zealand, where it occurs wherever its earthworm hosts are present.
Pollenia vagabunda
cluster fly
Pollenia vagabunda is a cluster fly in the family Polleniidae, widespread across Europe and introduced to North America, where it was first recorded in 1958. Unlike carrion-associated blow flies, this species has a life cycle tied to earthworms and other hosts rather than decomposition. Adults are known to overwinter in buildings and have been documented on carrion, though not tied to specific decomposition stages. The species has also been recorded in Algeria and shows potential forensic relevance.
Polycaon stoutii
Stout's branch borer, black polycaon, Stout's Hardwood Borer
Polycaon stoutii is a woodboring beetle in the family Bostrichidae. Adults are cylindrical, hairy, and black, measuring 10-23 mm. The species is native to western North America but has been introduced to other regions through wood commerce. It is known for exceptionally long larval development periods and occasional emergence from finished wood products.
Polydrusus impressifrons
Pale Green Weevil, Leaf Weevil
Polydrusus impressifrons is a small broad-nosed weevil native to Europe, introduced to North America in the early 20th century. It is polyphagous on hardwood trees and has been recorded in hybrid hazelnut orchards in Minnesota, where it may damage buds, foliage, and roots. Adults are active from late May to mid-July. The species is smaller, lighter, and has a broader head than the similar P. formosus.
Polyplacidae
spiny rat lice
Polyplacidae is a family of sucking lice (Anoplura) comprising approximately 193 species as of 2010. Members are obligate permanent ectoparasites of small mammals, with documented hosts including rodents (spiny rats, squirrels, pouched rats), lagomorphs (rabbits, hares), and primates (bushbabies, lemurs). The family exhibits cosmopolitan distribution. Molecular evidence suggests the family is paraphyletic and requires taxonomic revision.
Ponometia candefacta
Olive-shaded Bird-dropping Moth
Ponometia candefacta, commonly known as the olive-shaded bird-dropping moth, is a small noctuid moth native to North America. It has been deliberately introduced to Russia as a biological control agent for common ragweed (Ambrosia artemisiifolia). The species inhabits dry, disturbed, weedy areas at low elevations and is active during summer months.