Ectoparasite
Guides
Oeciacus vicarius
American swallow bug, cliff swallow bug, swallow nest bug
Oeciacus vicarius is a blood-feeding cimicid bug specialized as an ectoparasite of colonially nesting American cliff swallows (Petrochelidon pyrrhonota). It is widely distributed across North America, where it inhabits swallow nests in natural and anthropogenic structures. The species is a known vector of Buggy Creek Virus (Alphavirus, Togaviridae). Though it will bite humans when encountered, it does not establish persistent infestations in human dwellings.
Orchopeas howardi
Grey Squirrel Flea, squirrel flea
Orchopeas howardi is a flea species in the family Ceratophyllidae, commonly known as the grey squirrel flea. It is primarily associated with squirrels (family Sciuridae) as its typical hosts. The species has been documented in North America and Europe, with records from Great Britain, Ireland, France, and Belgium. A documented case from Illinois, USA, recorded this flea on wood ducklings (Aix sponsa), representing an accidental host association rather than typical host use.
Ornithocoris
Ornithocoris is a genus of hematophagous cimicid bugs that parasitize birds. Species in this genus are temporary ectoparasites, feeding on blood during all life stages and retreating to nests or shelter crevices between meals. The genus includes economically significant poultry pests, with O. toledoi documented from galliform hosts and parrots in South America and the southern United States.
Ornithoctona
Ornithoctona is a genus of louse flies (Hippoboscidae: Diptera) comprising 12 known species, all of which are obligate ectoparasites of birds. These winged or wing-reduced flies are blood-feeding parasites found worldwide except Antarctica. Several species have been documented expanding their ranges, with Ornithoctona laticornis recently recorded in Europe (Hungary, Romania) outside its native African distribution. The genus exhibits broad host associations across multiple avian orders, with some species showing low host specificity.
Ornithoica
Ornithoica is a genus of louse flies (family Hippoboscidae) comprising 23 described species. All species are obligate ectoparasites of birds. The genus is distinguished from other hippoboscid genera by morphological features and host associations. Species occur worldwide except Antarctica, with the greatest diversity in Southeast Asia.
Ornithoica vicina
Ornithoica vicina is a species of louse fly in the family Hippoboscidae, first described by Walker in 1849. This parasitic dipteran is known to infest birds, with a documented host record from the Marsh Hawk (Circus cyaneus). Louse flies in this family are obligate ectoparasites of birds and mammals, characterized by their dorsoventrally flattened bodies and reduced or absent wings in adults, adaptations that facilitate movement through host plumage or fur. The species has been recorded from multiple localities including Brazil and Hawaii.
Ornithomya
bird louse flies
Ornithomya is a genus of louse flies (family Hippoboscidae) comprising approximately 31 species of obligate avian ectoparasites. All species are blood-feeding parasites of birds, primarily Passeriformes. Adults are dorsoventrally flattened with reduced or absent wings in many individuals. The genus exhibits adenotrophic viviparity, with larvae developing entirely within the female and deposited as fully mature third instars that immediately pupate. Species show varying degrees of host specificity correlated with bird nesting ecology.
Ornithomyinae
avian louse flies
Ornithomyinae is a subfamily of louse flies (Hippoboscidae) comprising blood-feeding ectoparasites primarily of birds, with some species parasitizing mammals. The subfamily contains approximately 16 genera and over 160 species worldwide. Phylogenetic analyses indicate that Ornithomyinae as currently defined is not monophyletic, with at least one genus (Ornithoica) clustering separately from other members. These flies are obligate parasites that remain on their hosts for extended periods, feeding repeatedly on blood.
Ornithonyssus
bird mites, fowl mites, rat mites
Ornithonyssus is a genus of hematophagous mites in the family Macronyssidae. The genus includes economically important poultry pests such as the northern fowl mite (O. sylviarum) and tropical fowl mite (O. bursa), as well as the tropical rat mite (O. bacoti) which affects rodents and can bite humans. Species in this genus are obligate blood-feeders that complete their entire life cycle on the host or in close association with host nesting material. Several species have significant veterinary and medical importance due to their impacts on poultry production and potential to cause human dermatitis.
Ornithonyssus sylviarum
Northern Fowl Mite
Ornithonyssus sylviarum, commonly known as the northern fowl mite, is a blood-feeding ectoparasite of birds that has become a major economic pest of poultry worldwide. The entire life cycle occurs on the host, allowing populations to expand rapidly under favorable conditions. Heavy infestations cause anemia, reduced egg production, and can lead to death in severe cases. The mite has been reported on over 72 host species across 26 bird families and has shown ability to infest mammalian hosts including humans, though it does not permanently establish on non-avian hosts.
Otobius
spinose ear tick
Otobius is a genus of soft-bodied ticks in the family Argasidae. Adults possess a vestigial hypostome (feeding mouthpart) despite nymphs having a fully developed hypostome, and lack both eyes and a hood. The genus contains two species: O. lagophilus, associated with lagomorph hosts, and O. megnini, the spinose ear tick, which infests the ear canals of domestic and wild mammals. O. megnini is of veterinary significance due to its propensity to cause otitis, ear canal obstruction, and associated neurological symptoms in heavily infested hosts.
Otobius megnini
spinose ear tick
Otobius megnini, commonly known as the spinose ear tick, is a soft-bodied tick in the family Argasidae. Only the larval and nymphal stages are parasitic, residing deep within the external ear canals of mammals. Adults are non-feeding and free-living. The species has a worldwide distribution and is a significant veterinary pest of horses, cattle, sheep, goats, and dogs, causing otitis, irritation, and occasionally secondary complications such as muscle spasms or colic in horses.
Otodectes
ear mite
Otodectes is a genus of parasitic mites in the family Psoroptidae containing a single species, Otodectes cynotis, commonly known as the ear mite. These ectoparasites infest the external ear canals of domestic and wild carnivores, causing otitis externa. The genus is distributed worldwide and is of significant veterinary importance due to the intense irritation and secondary infections it can cause in host animals.
Otodectes cynotis
Ear Mange Mite, Ear Mite, Common Ear Mite
Otodectes cynotis is a parasitic mite in the family Psoroptidae, the sole species in its genus. It is a non-burrowing ectoparasite that inhabits the external ear canals of mammals, causing otitis externa. The mite completes its entire life cycle on a single host in approximately three weeks. It is distributed worldwide and primarily affects domestic cats, dogs, and ferrets, though it has been recorded on numerous other carnivores and occasionally humans. Infestation causes intense pruritus, head shaking, and ear scratching, and can lead to secondary bacterial infections in severe cases.
P. fuscus
Pandionacarus fuscus is a species of mite in the family Avenzoariidae, order Sarcoptiformes. The genus name indicates an association with the osprey genus Pandion, suggesting this mite may be an ectoparasite or commensal of ospreys. Very little published information exists on the biology or ecology of this species. The species was described by Nitzsch in 1818, indicating it has been recognized in scientific literature for over two centuries.
Pediculidae
Ape Lice
Pediculidae is a family of sucking lice (suborder Anoplura) that includes obligate ectoparasites of primates. The family contains Pediculus humanus, the human head and body louse, which exists as two morphologically similar but ecologically distinct forms: P. h. capitis (head louse) and P. h. humanus (body louse). Pediculidae also includes P. schaeffi, which infests chimpanzees and bonobos. These lice are wingless, dorsoventrally flattened insects with specialized mouthparts for piercing skin and feeding on blood. They complete their entire life cycle on the host and are of significant medical importance as vectors of epidemic typhus, trench fever, and relapsing fever.
Pediculus
sucking lice
Pediculus is the sole genus in the family Pediculidae, comprising obligate ectoparasitic sucking lice that infest primates. The genus includes species specialized to exploit distinct microhabitats on their hosts: Pediculus humanus humanus (body louse) inhabits clothing and body hair, while P. humanus capitis (head louse) is restricted to scalp hair. These insects are dorsoventrally flattened, wingless, and possess highly modified legs with clawed tarsi adapted for gripping hair shafts. All species feed exclusively on blood, making them significant pests and disease vectors of humans.
Pediculus humanus
Human Louse
Pediculus humanus is an obligate ectoparasite of humans comprising two subspecies: P. h. humanus (body louse) and P. h. capitis (head louse). This wingless insect has been associated with humans throughout recorded history and serves as a vector for several serious human diseases including epidemic typhus, trench fever, and relapsing fever. The body louse is larger and more robust than the head louse, with females capable of laying up to 295 eggs in their lifetime under optimal conditions. Both subspecies feed exclusively on human blood and complete their entire life cycle on the host.
Pediculus humanus capitis
Human Head Louse, Head Louse
The human head louse is an obligate ectoparasite specialized for life on human scalp hair. Unlike its close relative the body louse, it has remained associated with hair rather than clothing throughout human evolution. Populations in many regions have developed widespread resistance to pyrethrin and permethrin insecticides, complicating control efforts. Transmission occurs primarily through direct head-to-head contact, with infestations clustering in settings where children interact closely.
Pimeliaphilus
Pimeliaphilus is a genus of parasitic mites in the family Pterygosomatidae. Species within this genus are ectoparasites of insects and reptiles, with documented hosts including reduviid bugs (Triatoma, Meccus), tenebrionid beetles (Trachyderma), and geckos (Hemidactylus). The genus exhibits host specificity ranging from oligoxenous to stenoxenous patterns. Several species have been investigated for their potential as biological control agents against triatomine vectors of Chagas disease.
Podagrion
Podagrion is a genus of small parasitoid wasps in the family Torymidae that exclusively parasitize mantid egg cases (oothecae). Adults measure 2–3 mm and possess distinctive raptorial hind legs that mimic their mantis hosts, along with elongated ovipositors for penetrating oothecae. The genus exhibits a near-cosmopolitan distribution with strongest representation in Afrotropical, Neotropical, and Australasian regions. Podagrion demonstrates complex reproductive adaptations including multivoltine life cycles, phoretic oviposition behavior, and frequent sib-mating facilitated by limited dispersal.
Podoschistus
Podoschistus is a genus of ichneumon wasps in the subfamily Poemeniinae. The genus contains at least one North American species, P. vittifrons, which is an ectoparasitoid of wood-boring beetle larvae. These wasps use their elongated ovipositors to penetrate wood and deposit eggs on beetle grubs concealed within tree boles. The genus has undergone taxonomic revision, having been previously placed in the genera Xorides and Neoxorides.
Polyblastus stenocentrus
Polyblastus stenocentrus is a small ichneumon wasp in the tribe Tryphonini. It is a koinobiont ectoparasitoid of sawfly larvae, with females carrying unusually large egg loads compared to related idiobiont wasps. The species has been documented in Colorado and Alberta, Canada. Observations suggest females may carry egg clusters externally on the abdomen, a behavior whose function remains incompletely understood.
Polyctenidae
Polyctenid Bat Bugs
Polyctenidae is a small family of parasitic true bugs comprising 32 described species in five genera and two subfamilies. These insects are obligate hematophagous ectoparasites of bats, exhibiting high host specificity suggestive of co-evolution. The family is sister to Cimicidae (bed bugs) within the superfamily Cimicoidea. Subfamily Polycteninae occurs in the Eastern Hemisphere (Africa, Asia, Australia), while Hesperocteninae is restricted to the Western Hemisphere (North and South America).
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.
Polyplax
Mouse Lice
Polyplax is a genus of sucking lice in the family Polyplacidae. Species are permanent ectoparasites of small mammals, primarily rodents. The genus has cosmopolitan distribution across Europe, Africa, Asia, and Australasia. At least one species, Polyplax serrata, comprises distinct cryptic lineages with different host specificity strategies.
Pristepyris
Pristepyris is a genus of small parasitoid wasps in the family Bethylidae, comprising 38 described species distributed across the Old World and New World except the Australian Region. Members of this genus are ectoparasites of click beetle larvae (Elateridae). The genus has been subject to recent taxonomic revision, particularly for Taiwanese and Ryukyuan species.
Protocalliphora sialia
birdnest blowfly
Protocalliphora sialia is a parasitic blowfly that infests the nests of cavity-nesting birds. Larvae are nest-dwelling, intermittent ectoparasites that feed on nestling blood. The species has been documented from multiple host species including tree swallows, eastern bluebirds, and ferruginous pygmy-owls. Wolbachia bacterial infections show geographic variation across the species' range.
Pseudolynchia
pigeon louse flies
Pseudolynchia is a genus of blood-feeding louse flies (Hippoboscidae) comprising five described species. All species are obligate ectoparasites of birds. The genus is best known for P. canariensis, commonly called the pigeon louse fly, which has been extensively studied as a vector of avian malaria parasites. Members exhibit the family-characteristic pupiparous reproduction, in which females retain and nourish larvae internally until depositing a fully formed prepupa.
Pseudolynchia canariensis
pigeon louse fly, pigeon fly
Pseudolynchia canariensis is an obligate ectoparasitic louse fly in the family Hippoboscidae that specializes on pigeons and doves (Columbidae). It is a significant vector of Haemoproteus columbae, the causative agent of pigeon malaria, serving as the definitive host where sexual reproduction of the parasite occurs. The species exhibits adenotrophic viviparity, producing one prepupa at a time that is deposited in the host's nest or roosting site. Both sexes feed exclusively on blood. The fly has been documented in numerous regions worldwide, particularly where domestic pigeons are kept, and shows limited ability to survive on human blood.
Psoroptidae
Scab Mite
Psoroptidae is a family of parasitic mites in the order Sarcoptiformes. Members are 1–2 mm in length and inhabit the surface of host skin rather than burrowing into it. The family includes economically important genera such as Psoroptes, Chorioptes, and Otodectes, which cause mange and skin disease in mammals. Host associations span domestic animals (sheep, cattle, horses, dogs, cats, rabbits) and wildlife including African monkeys and various bird species.
Pterygosomatidae
scale mites
Pterygosomatidae is a family of prostigmatic mites in the order Trombidiformes, commonly known as scale mites. These mites are obligate ectoparasites of lizards, primarily infesting the skin and scales of their reptilian hosts. The family includes multiple genera, notably Pterygosoma, Geckobia, Geckobiella, Pimeliaphilus, and Neopterygosoma. Species within this family exhibit high host specificity, with particular mite lineages associated with specific lizard families including Agamidae, Gekkonidae, Liolaemidae, and Gerrhosauridae.
Pterygosomatoidea
Pterygosomatoidea is a superfamily of mites within the order Trombidiformes. These arachnids are part of the diverse Prostigmata lineage, which includes many parasitic and predatory mite groups. The superfamily encompasses several families of mites that are primarily associated with reptiles as hosts. They represent a specialized evolutionary radiation within the Eleutherengona infraorder.
Pthiridae
Pubic Lice
Pthiridae is a family of sucking lice containing the single genus Pthirus with two extant species: Pthirus pubis (human pubic louse) and Pthirus gorillae (gorilla louse). These obligate ectoparasites are highly host-specific, with each species restricted to a single primate host. The two species diverged approximately 3-4 million years ago, possibly associated with a host switch from gorillas to humans. Members of this family possess dorsoventrally flattened bodies and broad, crab-like claws adapted for grasping coarse hair.
Pthirus pubis
Crab Louse, Pubic Louse, Crabs
Pthirus pubis is an obligate ectoparasite of humans, the sole species in its genus to infest humans. It is dorsoventrally flattened, wingless, and 1-2 mm in length, with a crab-like appearance due to its broad, short body and specialized clawed legs adapted for grasping coarse human hair. The species has infested humans for approximately 10,000 years, with archaeological evidence from Roman and Medieval Britain, pre-Columbian South America, and southern Peru. Unlike the closely related head and body lice (Pediculus humanus), P. pubis is extremely sedentary, rarely leaving direct contact with the host body, and is transmitted primarily through sexual contact.
Pulex
human flea (for P. irritans)
Pulex is a genus of fleas in the family Pulicidae, established by Linnaeus in 1758. The genus comprises six to seven recognized species, with Pulex irritans (the human flea) being the most notable and widespread. The remaining species are restricted to the Nearctic and Neotropical realms. Members of this genus are laterally compressed, wingless ectoparasites adapted for blood-feeding on mammals.
Pulicidae
Common Fleas
Pulicidae is a family of fleas (Siphonaptera) containing 181 species in 27 genera. Members are wingless, laterally compressed ectoparasites of mammals with exceptional jumping ability enabled by the elastic protein resilin. The family includes significant pests such as the cat flea (*Ctenocephalides felis*), dog flea (*C. canis*), and human flea (*Pulex irritans*), which are vectors of disease and parasites.
Ricinidae
Ricinidae is a family of chewing lice within the suborder Amblycera. All species are relatively large-bodied avian ectoparasites that feed on host blood, an atypical trait among chewing lice. The family includes three recognized genera: Ricinus (65 species, parasitizing Passeriformes), Trochiliphagus (13 species, on hummingbirds), and Trochiloecetes (30 species, also on hummingbirds but restricted to head and neck). Ricinids typically exhibit low prevalence and low intensity infestations with strongly female-biased sex ratios.
Sarcoptes
itch mite, mange mite
Sarcoptes is a genus of parasitic mites in the family Sarcoptidae. The genus contains species that are permanent obligate ectoparasites of mammals, most notably *Sarcoptes scabiei*, which causes scabies in humans and sarcoptic mange in livestock, wildlife, and companion animals. These mites burrow into the epidermis of their hosts, where they feed, reproduce, and complete their entire life cycle. Infestations cause intense pruritus, skin lesions, and significant economic and health impacts globally. Taxonomic treatment varies: some authorities recognize multiple host-specific varieties of *S. scabiei*, while others treat these as distinct species.
Sarcoptes scabiei
Scabies Mite, Itch Mite
Sarcoptes scabiei is a parasitic mite that burrows into the epidermis of mammals, causing scabies in humans and sarcoptic mange in animals. The mite has a cosmopolitan distribution and infests numerous host species including humans, domestic animals, and wildlife. Adult females create characteristic S-shaped burrows in the stratum corneum where they deposit eggs. The disease produces intense pruritus through host immune responses to mites, eggs, and fecal pellets. Different host-adapted variants exist, though cross-infectivity between closely related hosts has been documented.
Scoliidae
Scoliid Wasps, Mammoth Wasps
Scoliidae is a family of solitary aculeate wasps comprising approximately 300-560 described species worldwide. They are robust, often large-bodied wasps with distinctive corrugated wing tips. Females are parasitoids of scarab beetle larvae, using their stings to paralyze hosts before depositing eggs. The family exhibits pronounced sexual dimorphism: males have longer antennae and more slender bodies, while females possess shorter antennae and true stingers. Scoliids are considered beneficial insects due to their role in controlling scarab pest populations.
Scutellista caerulea
Scutellista caerulea is a small parasitoid wasp in the family Pteromalidae, widely used as a biological control agent against soft scale insects (Coccoidea). The species is an ectoparasitoid, with larvae feeding externally on host eggs concealed beneath the adult scale insect's body. Laboratory studies have established optimal rearing conditions at 30–33°C with 12–14 hours of daylight and supplementary carbohydrate nutrition for adults. The species demonstrates particular effectiveness in tropical environments where other parasitoids may fail.
Siphonaptera
fleas, pireler (Turkish)
Siphonaptera (fleas) are small, wingless, holometabolous insects that are obligate ectoparasites of mammals and birds. Adults are 2–5 mm long, bilaterally flattened, and possess enlarged hind legs adapted for jumping. Larvae are legless, worm-like, and feed on organic debris including blood clots and adult flea feces. The order comprises approximately 2,500 described species, with roughly 94% parasitizing mammals and 6% specializing on birds. Some species are significant vectors of human and animal pathogens, including plague, typhus, and tularemia.
Siphonostomatoida
Siphon-mouth Copepods
Siphonostomatoida is an order of copepods distinguished by siphon-like mandibles and a frontal filament used for host attachment. The order comprises 40 recognized families, with approximately 75% of all fish-parasitizing copepods belonging to this group. Most species are marine symbionts, though a few inhabit freshwater environments. Members exhibit diverse host associations, with 17 families parasitizing vertebrates (primarily fishes) and 23 families associated with invertebrates.
copepodparasitemarinefish-parasitesymbiontcrustaceanectoparasiteSiphonostomatoidabiodiversitySouthern-AfricaJapanBrazilsponge-associatecoral-associatedevelopmental-stageschalimusfrontal-filamentsiphon-mandibleAsterocheridaeLernaeopodidaePennellidaeHatschekiidaeSphyriidaeNotodelphyidaeBotryllophilidaeSolenopotes capillatus
Little Blue Cattle Louse, Tubercle-bearing Louse
Solenopotes capillatus is the smallest of the sucking lice species that parasitize cattle. It is a relatively immobile ectoparasite with a worldwide distribution tied to domestic livestock. The species is most commonly found on the head of its host, particularly the face. It is known by different common names in different regions: "little blue cattle louse" in the United States and "tubercle-bearing louse" in Australia.
Spathius elegans
Spathius elegans is a doryctine braconid wasp described by Matthews in 1970. It is widespread in the eastern United States. The species is an ectoparasite of larvae in the sawfly genus Xiphydria.
Spinturnicidae
bat wing mites
Spinturnicidae is a family of hematophagous mites in the order Mesostigmata. All species are obligate ectoparasites of bats, living their entire life cycle on the host. They infest wing membranes, tail membranes, and occasionally eyelids and eye canthi. The family has a worldwide distribution in bat habitats and comprises 11 genera.
Stethorus pusillus
Dot Ladybird
Stethorus pusillus is the smallest European ladybird beetle, belonging to the family Coccinellidae and subfamily Scymninae. This species has been documented as a host for the ectoparasitic fungus Hesperomyces coccinelloides, with the first Polish records representing the northernmost and easternmost occurrence of this fungus. The species has been collected from roadside willow trees and floodplain forests in Poland, and is known from various European localities including Spain and Belgium, as well as from the Azores islands.
Stomoxys
stable flies
Stomoxys is a genus of muscid flies distinguished by its blood-feeding ectoparasitic lifestyle, unusual among the Muscidae. The genus comprises approximately 20 described species, with Stomoxys calcitrans (stable fly) being the most economically significant and widely distributed. Species in this genus are obligate hematophages of mammals, causing substantial livestock losses through blood loss, stress, and disease transmission. Current phylogenetic evidence suggests the genus is paraphyletic.
Streblidae
streblid bat flies, bat flies
Streblidae are a family of highly specialized dipteran flies in the superfamily Hippoboscoidea, comprising approximately 237 species in 33 genera. They are obligate ectoparasites of bats, exhibiting extreme morphological adaptations including variable wing reduction (from fully winged to completely wingless), eye degeneration, and dorsoventrally flattened bodies. The family shows pronounced host specificity, with individual fly species typically restricted to particular bat host species. Streblidae are classified as pupiparous flies, meaning females retain and nourish larvae internally until they are deposited as fully developed prepupae.