Inquiline
Guides
Adranes
ant-loving beetles
Adranes is a genus of obligately myrmecophilous beetles in the rove beetle family Staphylinidae. These small beetles are entirely dependent on ants of the genus Lasius, living as inquilines within their nests. The six described species share extreme morphological adaptations for this lifestyle, including complete eyelessness, reduced mouthparts, and highly modified antennae. They are known from North America, with species distributed across the United States and Pacific coast regions.
Ametrodiplosis
Ametrodiplosis is a genus of gall midges in the tribe Clinodiplosini, established by Rübsaamen in 1910. Species in this genus are distributed primarily across the Holarctic region and exhibit two distinct life history strategies: some induce galls on host plants, while others live as inquilines within existing galls. The genus demonstrates broad host associations across multiple seed plant families including Apocynaceae and Caryophyllaceae. Molecular phylogenetic analysis has supported the monophyly of Ametrodiplosis despite this ecological diversity.
Andricus mamillaformis
A cynipid gall wasp in the genus Andricus that induces distinctive galls on oak hosts. Like other members of this large genus, it exhibits high host specificity typical of gall wasps, with each species producing a characteristic gall morphology that serves as both shelter and food source for developing larvae. The species name 'mamillaformis' suggests a nipple- or breast-shaped gall form.
Andricus nigricens
Andricus nigricens is a species of cynipid gall wasp in the family Cynipidae. Like other members of the genus Andricus, this species induces characteristic galls on oak (Quercus) host plants. The species is part of a highly diverse radiation of gall-forming wasps that have evolved intimate relationships with oaks, with each species typically producing a distinct gall morphology on specific plant tissues.
Anergates
Anergates is a genus of myrmicine ants containing the single species Anergates atratulus, an extreme workerless social parasite. The species lacks a worker caste and depends entirely on host colonies of Tetramorium ants for survival and reproduction. It is listed on the IUCN Red List of threatened species.
Anergates atratulus
Anergates atratulus is an extreme workerless social parasite (inquiline) ant that lives exclusively within colonies of Tetramorium host species. It is one of the most specialized ant parasites known, lacking a worker caste entirely and producing only sexual forms (males and queens). The species is IUCN Red-Listed and considered rare across its European range.
Anthonomus convictus
Anthonomus convictus is a small weevil species described by Gates and Burke in 1972. It has been documented living within the galls formed by the moth Heliozela aesella, making it one of the few weevils known to inhabit lepidopteran galls. The species is known from limited observations in eastern North America.
Antron
Antron is a genus of gall wasps in the family Cynipidae. These insects induce distinctive galls on oak trees (Quercus species), with the urchin gall induced by A. quercusechinus being particularly notable for its striking appearance. The genus belongs to the tribe Cynipini, which contains the majority of oak gall wasps. Species in this genus are specialized to specific oak hosts and gall locations.
Atrusca capronae
striped oak-apple gall wasp
Atrusca capronae, commonly called the striped oak-apple gall wasp, is a cynipid wasp species that induces characteristic galls on oak leaves in southwestern North America. The species is most frequently observed in Arizona but occurs throughout the region where its host plants grow. The wasp's common name derives from the striped appearance of the galls it produces, though stripe intensity varies geographically. The species is considered fairly common within its range.
Attaphila
Attaphila is a genus of minute myrmecophilous cockroaches that inhabit the fungus gardens of leaf-cutting ants. The genus comprises nine described species, divided into two host-specific groups: the bergi-group associated with Acromyrmex ants, and the fungicola-group associated with Atta ants. These cockroaches possess unique morphological adaptations for life within ant colonies, including specialized antennal structures and modified leg morphology.
Attaphila fungicola
ant cockroach
Attaphila fungicola is a small myrmecophilous cockroach species described by Wheeler in 1900. The species is notable for its obligate association with leaf-cutter ants (Atta spp.), living within ant colonies. It belongs to the family Ectobiidae and has been documented in Texas and other parts of North America. The common name "ant cockroach" reflects this specialized ecological relationship.
Belonocnema
Belonocnema is a genus of cynipid gall wasps restricted to the southeastern United States. The genus comprises three recognized species that induce distinct galls on section Virentes oaks, including live oaks. All species exhibit heterogony, with alternating sexual and asexual generations producing morphologically and ecologically different gall types. The genus has been subject to taxonomic revision, with Dryorhizoxenus now synonymized under Belonocnema.
Bombus citrinus
lemon cuckoo bumblebee
Bombus citrinus is a cuckoo bumblebee native to eastern North America, recognized by its lemon-yellow coloration. As an obligate social parasite, it invades colonies of other bumblebees, kills the resident queen, and assumes control of the host worker population. It belongs to the subgenus Psithyrus, a group of parasitic bumblebees that have lost the ability to collect pollen and rear their own workers.
Cacoxenus indagator
Houdini fly
Cacoxenus indagator is a kleptoparasitic fruit fly native to central and southern Europe that has been introduced to North America. Females lay eggs in the pollen-filled nest cells of cavity-nesting solitary bees, particularly mason bees (Osmia species). The larvae consume pollen stores intended for host bee larvae, causing host mortality or reduced adult size. The species is commonly called the "Houdini fly" for its ability to escape sealed nest cells. It poses a significant threat to managed solitary bee populations in commercial pollination operations.
Callirhytis quercusmodesta
Callirhytis quercusmodesta is a species of gall wasp in the family Cynipidae. The species induces galls on oaks (Quercus spp.) as part of its life cycle. Like other members of the genus Callirhytis, it exhibits heterogony, with alternating sexual and asexual generations that produce morphologically distinct galls. The species is known from the central United States.
Callirhytis seminosa
Callirhytis seminosa is a species of gall wasp in the family Cynipidae. Like other members of its genus, this species induces galls on oak hosts (Quercus spp.). The genus Callirhytis is known for forming distinct galls on oaks, with different species typically associated with specific oak species or gall morphologies. The specific epithet "seminosa" suggests a possible association with seed or acorn-related structures, though this remains speculative without direct observation.
Ceroptres
Ceroptres is a genus of gall wasps in the tribe Ceroptresini (Cynipidae). The genus includes 43 described species, of which 40 are known from North America. Ceroptres species are inquilines: they do not induce their own galls but instead oviposit into galls formed by other organisms. Host galls are primarily those induced by other gall wasps (Cynipini), though some species use galls formed by gall midges (Cecidomyiidae). Species are host specialists, typically associated with a single host gall species or with several phylogenetically or ecologically related galls.
Ceroptresini
Ceroptresini is a tribe of inquiline gall wasps in the family Cynipidae, containing two genera: Ceroptres (with 43 species) and Buffingtonella (with one species). First established as a tribe in 2015, these wasps are predominantly found in North America, though some species occur in the Eastern Palearctic and Oriental regions. Members of this tribe do not induce their own galls but instead inhabit galls created by other cynipid wasps, primarily on oaks (Quercus spp.), with some species reared from cecidomyiid midge galls.
Cremastocheilus armatus
anteater scarab beetle
Cremastocheilus armatus is a myrmecophilous scarab beetle specialized for life within ant colonies. The species exhibits extreme morphological adaptations including reduced eyes, shortened elytra exposing most of the abdomen, and dense trichomes on abdominal tergites. Males display prominent pronotal horns absent in females. The beetle integrates into host ant colonies where it obtains food through interactions with worker ants.
Cremastocheilus wheeleri
Cremastocheilus wheeleri is a myrmecophilous scarab beetle in the genus Cremastocheilus, commonly known as anteater scarabs. Adults and larvae live within ant colonies as predators, feeding on ant larvae and pupae. The species exhibits specialized morphological adaptations for surviving in hostile ant nests, including dense exoskeletal armor, modified mouthparts for piercing ant brood, and death-feigning behavior to gain entry to nests. It is found in western and central North America, primarily associated with mound-building ants in the genus Formica.
Crematogaster lineolata
Small-lined Acrobat Ant
Crematogaster lineolata is a species of acrobat ant in the genus Crematogaster, characterized by its ability to raise its abdomen over its thorax when disturbed. The species has been documented in grassland habitats of northeastern Kansas, where it engages in a notable mutualistic relationship with the clytrine leaf beetle Anomoea flavokansiensis. Ant workers are attracted to beetle eggs, carry them into their nests, and provide a protected environment for beetle larval development. The species is part of the diverse Crematogaster genus, which contains numerous species worldwide.
Cynipidae
Gall Wasps, Gallflies
Cynipidae is a family of minute wasps (1–8 mm) renowned for inducing plant galls—abnormal growths that provide shelter and nutrition for developing larvae. The family comprises approximately 1,300 described species worldwide, with major radiations on oaks (Quercus) and roses (Rosa). Many species exhibit complex life cycles involving alternation of sexual and asexual (parthenogenetic) generations, often producing morphologically distinct galls. Gall induction involves chemical manipulation of host plant tissue, with enlarged venom glands implicated in this process. The family evolved from parasitoid ancestors and represents one of the most diverse groups of gall-forming insects.
Cynips conspicuus
Fuzzy Gall Wasp
Cynips conspicuus, commonly known as the Fuzzy Gall Wasp, is a species of gall wasp in the family Cynipidae. The species is known for inducing galls on oak trees. It has been documented in 1,259 iNaturalist observations, indicating it is relatively well-observed among gall wasp species.
Diastrophus nebulosus
Blackberry Knot Gall Wasp
Diastrophus nebulosus is a cynipid gall wasp that induces compound stem galls on Rubus flagellaris. It exhibits arrhenotoky, the first reported instance of this reproductive mode for a Nearctic species in the genus Diastrophus. The species supports a complex community of parasitoids and inquilines, with heavy infestation reducing primary host populations to near zero in some colonies over 1-2 seasons.
Diplolepis polita
Spiny Leaf Gall Wasp
Diplolepis polita is a gall wasp in the family Cynipidae, first described by William Harris Ashmead in 1890. The species induces distinctive spherical, spiny galls on the leaves of wild roses, primarily Rosa acicularis and Rosa arkansana, in spring and early summer. Originally known only from western North America west of the Rocky Mountains, it has demonstrated host flexibility by colonizing the introduced domestic shrub rose Rosa rugosa in urban environments. This host shift provides insight into the vagility and host specificity of cynipid wasps.
Diplolepis rosae
Mossy Rose Gall Wasp, Rose Bedeguar Gall Wasp, Robin's Pincushion Gall Wasp
A gall-inducing wasp in the family Diplolepididae that forms distinctive mossy, pincushion-like galls on wild roses, primarily Rosa canina and Rosa arvensis. The species is notable for its predominantly parthenogenetic reproduction, with fewer than 5% males in most populations. Females lay up to 60 eggs in developing rose buds, inducing chemically-driven plant tissue distortion that creates the characteristic bedeguar gall. The wasp has been introduced to North America alongside cultivated roses.
Doryctinae
doryctine wasps
Doryctinae is a large, diverse subfamily of parasitoid wasps within Braconidae, comprising over 2000 species in 198 genera. Members range from 1 to 25 mm and exhibit remarkable morphological diversity, including many flightless or wingless species. The subfamily is characterized by distinctive structural features including a cyclostome mouth and spines on the foreleg tibia. Most species are idiobiont ectoparasitoids of wood-boring beetle larvae, though host associations vary considerably across the group.
Epuraea aestiva
Epuraea aestiva is a species of sap-feeding beetle in the family Nitidulidae. It has been recorded as an inquiline in nests of the bumble bee Bombus derhamellus, where its larvae and pupae develop. The species is widely distributed across the Holarctic region, including Europe, Northern Asia (excluding China), and North America.
Eugnosta erigeronana
fleabane cochylid moth
Eugnosta erigeronana, commonly known as the fleabane cochylid moth, is a small tortricid moth with a wingspan of 11–13 mm. It occurs across the southeastern and central United States. The species has an extended flight period from February through October. Its larvae develop within galls induced by cecidomyiid flies on Erigeron species.
Formicoxenus hirticornis
Dogwood Guest Ant
Formicoxenus hirticornis is a small myrmicine ant species in the genus Formicoxenus, commonly known as the Dogwood Guest Ant. Species in this genus are specialized social parasites that inhabit nests of larger host ant species, particularly those in the genus Myrmica. The specific epithet 'hirticornis' refers to hairy antennae. This species is rarely encountered and poorly documented in scientific literature.
Gasteruption
carrot wasps
Gasteruption is a genus of parasitoid wasps commonly known as "carrot wasps" due to their slender, elongated bodies and frequent association with umbelliferous flowers. The genus comprises approximately 64 species worldwide, with 21 species recorded in Central Europe and at least 15 in North America. Adults are characterized by a pronounced "neck" between the head and thorax, an abdomen attached high on the thorax, and enlarged hind tibiae that function in flight dynamics and vibrational sensing. Females possess long ovipositors for accessing host nests. Larvae are predator-inquilines in the nests of solitary bees and wasps.
Gasteruption assectator
wild carrot wasp
Gasteruption assectator, commonly known as the wild carrot wasp, is a species of carrot wasp in the family Gasteruptiidae. It is a generalist inquiline parasitoid that targets multiple bee and wasp species including Hylaeus confusus, Hylaeus pectoralis, and Pemphredon fabricii. The species exhibits the distinctive elongated neck and enlarged hind tibiae characteristic of its family. Adults are frequently observed at flowers, particularly umbelliferous blooms.
Geomysaprinus floridae
Equal-clawed Gopher Tortoise Hister Beetle, clown beetle
Geomysaprinus floridae is a species of clown beetle in the family Histeridae. It is known by the common name Equal-clawed Gopher Tortoise Hister Beetle, indicating a likely association with gopher tortoise burrows. The species was described by Horn in 1873 and occurs in North America, with records from Florida. Like other members of Histeridae, it belongs to a family of beetles commonly known as clown beetles or hister beetles, many of which are associated with decaying organic matter and animal burrows.
Geomysaprinus xerobatis
Geomysaprinus xerobatis is a species of clown beetle in the family Histeridae. It belongs to the genus Geomysaprinus, a group specialized for association with fossorial mammals. The species epithet "xerobatis" references its documented association with desert-dwelling pocket gophers.
Gnorimoschemini
Gnorimoschemini is a tribe of small moths within the subfamily Gelechiinae (family Gelechiidae). Members are generally small, narrow-winged moths with drab coloration. The tribe includes species with diverse larval habits, including gall inquilines that develop within pre-existing plant galls rather than inducing their own.
Idarnes
Idarnes is a genus of chalcid wasps in the family Agaonidae (fig wasps), first described by Walker in 1843. These wasps are associated with fig trees (Ficus), where they develop as inquilines or parasitoids within fig syconia. The genus is part of the subfamily Sycophaginae, a group of non-pollinating fig wasps that exploit fig resources without providing pollination services. Idarnes species are found primarily in the Neotropics.
Limnophyes viribus
A recently described non-biting midge (Diptera: Chironomidae) known for its distinctive inquiline behavior. Larvae inhabit vacated leaf mines created by Metriocnemus erythranthei rather than excavating their own tunnels. Described in 2023 from collections in Iowa and Oregon, USA.
Metriocnemus erythranthei
Monkeyflower Non-biting Midge
Metriocnemus erythranthei is a leaf-mining chironomid midge (Diptera: Chironomidae: Orthocladiinae) described in 2023 from herbaceous wetland plants. The larva is a true miner that enters fresh leaves and excavates tunnels, feeding on leaf tissue of monkeyflowers, speedwells, and other herbaceous plants. The species is widespread across North America, with documented collections from the Pacific coast to Pennsylvania. Its vacated mines are subsequently inhabited by Limnophyes viribus, establishing an inquiline relationship.
Microdon cothurnatus
orange-legged ant fly
Microdon cothurnatus, known as the orange-legged ant fly, is a syrphid fly species documented across the Northern United States and Canada. Unlike most hoverflies, adults are rarely observed at flowers. The species is notable for its ant-associated life history: larvae develop within ant nests.
Microdon craigheadii
Large Metallic Ant Fly
Microdon craigheadii is a species of syrphid fly described by Walton in 1912. As a member of the genus Microdon, it belongs to a group known for their unusual life history: the larvae are inquilines in ant nests, living within ant colonies rather than being free-living predators like most hover fly larvae. The species has been documented in North America, with records contributing to understanding of hover fly diversity and distribution patterns. It is one of approximately 6,200 described species of syrphid flies worldwide.
Microdon fulgens
Rainbow Ant Fly
Microdon fulgens is a species of syrphid fly (Syrphidae) in the subfamily Microdontinae. Members of the genus Microdon are commonly known as ant flies due to their unusual life history: larvae develop as inquilines within ant colonies. The specific epithet "fulgens" (Latin for shining or gleaming) likely refers to the adult's appearance. As with other Microdon species, adults are pollinators, while larvae have a highly specialized ecological relationship with ants.
Microdon globosus
Globular Ant Fly
Microdon globosus is a species of syrphid fly in the family Syrphidae, commonly known as the Globular Ant Fly. Like other members of the genus Microdon, it belongs to a distinctive group of hover flies whose larvae develop within ant colonies. The species was first described by Fabricius in 1805 and has been documented in museum collections and citizen science observations, though detailed natural history information remains limited.
Mixogaster fattigi
Fattig's Ant Fly
Mixogaster fattigi is a species of ant-mimicking hoverfly (family Syrphidae, subfamily Microdontinae) described in 2019. The genus Mixogaster belongs to the tribe Microdontini, a group whose larvae are known to develop within ant colonies as inquilines or predators of ant brood. The specific epithet honors entomologist Delbert La Rue Fattig. The species is part of a lineage exhibiting remarkable morphological convergence with ants, representing an evolutionary strategy to avoid predation while foraging or accessing ant-associated resources.
Mordellistena convicta
tumbling flower beetle, gall-boring beetle, inquiline beetle
Mordellistena convicta is a gall-boring beetle in the family Mordellidae, described by LeConte in 1862. The species is an inquiline that inhabits galls induced by the goldenrod gall fly (Eurosta solidaginis) on goldenrod plants (Solidago spp.). It has been studied as a model system for sequential radiation and host-associated speciation, with populations showing differentiation corresponding to the host races of their gall fly associates. Adults use olfactory cues from gall tissues to locate suitable host plants for mating and oviposition.
Myrmechixenini
Myrmechixenini is a tribe of darkling beetles (family Tenebrionidae) established by Jacquelin du Val in 1858. The tribe belongs to the subfamily Diaperinae within the speciose family Tenebrionidae, one of the largest families of beetles. Members of this tribe are characterized by their association with ant colonies, reflecting the etymology of the name (from Greek myrmex, ant, and xenia, hospitality). The tribe contains relatively few described species and is poorly represented in collections, with only 13 observations recorded on iNaturalist.
Myrmecoblatta
Ant Cockroaches
Myrmecoblatta is a genus of small cockroaches in the family Corydiidae, commonly called ant cockroaches. These insects are myrmecophiles, living in close association with ant colonies. The genus was established by Mann in 1914 and contains species found in the southern United States, Mexico, and Central America. They represent a specialized evolutionary lineage adapted to life within ant nests.
Myrmecoblatta wheeleri
Wheeler's Ant Cockroach
Myrmecoblatta wheeleri is a small, myrmecophilous cockroach species known for its obligate association with ant colonies. First described by Hebard in 1917, this species inhabits the nest chambers of host ants, where it has been observed in Costa Rica, Guatemala, and Florida. The species represents one of the few documented cases of true myrmecophily in cockroaches, having evolved specialized adaptations for life within ant societies. Its common name honors the American entomologist William Morton Wheeler, who conducted pioneering studies on ant ecology and myrmecophilous organisms.
Myrmecophilus americanus
American ant cricket, ant cricket
Myrmecophilus americanus is a wingless cricket that lives as an obligate parasite within ant nests. It is kleptoparasitic, feeding on food scraps brought by worker ants and encouraging them to regurgitate food. The species shows host specificity to the longhorn crazy ant (Paratrechina longicornis), though occasional records from other ant species exist. Its body shape and size resemble the gaster of the ant queen, possibly assisting its integration into the colony through mimicry.
Odontofroggatia
Odontofroggatia is a genus of non-pollinating fig wasps in the family Epichrysomallidae. The genus is associated with a narrow range of host fig species, specifically Ficus microcarpa and Ficus prasinicarpa. Members develop within fig fruits as parasitoids or inquilines. The genus was established by Ishii in 1934.
Ormyridae
Ormyridae is a small family of parasitic wasps in the superfamily Chalcidoidea. Members are parasitoids or hyperparasitoids of gall-forming insects, primarily cynipid wasps and tephritid flies. The family comprises approximately 153 species across three subfamilies (Asparagobiinae, Hemadinae, Ormyrinae) and several genera, with the majority in the genus Ormyrus. Ormyridae has a cosmopolitan distribution but is almost entirely absent from South America. Adults of many species exhibit iridescent coloration and distinctive metasomal sculpturing.