Cynipidae
Guides
Atrusca
Atrusca is a genus of gall wasps in the family Cynipidae, tribe Cynipini, comprising approximately 42 species distributed across North and Central America. These tiny wasps are specialized herbivores that induce characteristic galls on oak (Quercus) host plants. The genus forms a phylogenetically distinct clade most closely related to Cynips, Philonix, and Xanthoteras, and morphologically resembles Cynips and Antron. Species exhibit high host specificity, with each typically restricted to one or a few closely related oak species.
gall-waspCynipidaeoak-gallQuercusherbivoreparasitoidNorth-AmericaMexicoCentral-AmericaCynipiniinduced-gallplant-insect-interactionhost-specificityalternation-of-generationsasexual-reproductionsexual-reproductionecosystem-engineerinquilinehyperparasitoidbella-species-complexphylogeneticstaxonomyKinsey-1930Atrusca aggregata
Atrusca aggregata is a species of cynipid gall wasp described by Weld in 1926. Like other members of the family Cynipidae, this tiny wasp induces the formation of characteristic galls on oak leaves. The genus Atrusca is known for producing colorful, detachable leaf galls on various Quercus species. Adult females emerge from galls and use their ovipositor to inject eggs into leaf tissues, initiating the next generation of galls.
Atrusca brevipennata
little oak-apple gall wasp
Atrusca brevipennata is a cynipid gall wasp that produces distinctive galls on oak leaves in western North America. Formerly known as Andricus pellucidus, this species was first described by Gillette in 1893 and later studied by Alfred Kinsey. The wasp is locally common in the American Southwest, with records extending as far north as Denver. It oviposits into leaves of shrub live oak (Quercus turbinella) and Gambel oak (Q. gambelii), inducing the formation of small oak-apple galls. The species is visually similar to Atrusca bella and may be confused with it in the field.
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.
Atrusca carolina
Atrusca carolina is a species of gall wasp in the family Cynipidae. Like other members of the genus Atrusca, this species induces galls on oak leaves. The genus is known for producing colorful and structurally distinctive galls on Quercus species. Specific details about A. carolina's biology, host associations, and distribution remain poorly documented in available literature.
Atrusca cubitalis
Atrusca cubitalis is a species of cynipid gall wasp, a group of tiny wasps known for inducing characteristic plant galls on their host plants. As a member of the family Cynipidae, this species exemplifies the highly specialized host relationships typical of gall wasps, where each species typically induces a distinct gall type on a specific host plant or closely related group of plants. The genus Atrusca is known for producing colorful and structurally distinctive galls on oak leaves (Quercus spp.), with A. cubitalis specifically associated with post oak (Quercus stellata) based on related species observations. The life cycle involves the female wasp using her ovipositor to inject eggs into leaf tissue, after which the developing larvae secrete plant growth hormones that cause the formation of a specialized gall structure within which they feed and develop.
Aulacidea
Aulacidea is a genus of herb gall wasps in the family Cynipidae, tribe Aylacini. Species in this genus induce galls on herbaceous plants, particularly in the Asteraceae and Plantaginaceae families. The genus is considered basal within the cynipid complex and exhibits relatively simple gall developmental patterns compared to more derived cynipid lineages. Aulacidea species support diverse parasitoid communities, with some species serving as hosts for multiple parasitoid wasps.
Aulacidea acroptilonica
Russian Knapweed Gall Wasp
Aulacidea acroptilonica is a species of gall wasp in the family Cynipidae, commonly known as the Russian Knapweed Gall Wasp. It is a specialist herbivore that induces galls on its host plant. The species is native to regions associated with Russian knapweed and has been recorded in the conterminous United States. Like other members of the genus Aulacidea, it is likely targeted by parasitoid wasps. The species was described by Tyurebaev in 1979.
Aulacidea harringtoni
Aulacidea harringtoni is a species of gall wasp in the family Cynipidae, first described by Ashmead in 1887. The genus Aulacidea comprises gall-forming wasps that induce galls on host plants. Distribution records indicate presence in North America, specifically in Canada including Ontario.
Aulacideini
herb gall wasps
Aulacideini is a tribe of herb gall wasps within the family Cynipidae. Members of this tribe induce galls on herbaceous plants, with documented associations spanning multiple plant families including Asteraceae, Lamiaceae, Papaveraceae, and Plantaginaceae. The tribe has undergone significant taxonomic revision based on molecular phylogenetic analyses, resulting in refined generic boundaries. Notable genera include Aulacidea, Antistrophus, Neaylax, and the recently erected Fumariphilus.
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.
Bootanomyia
Bootanomyia is a genus of parasitoid wasps in the family Megastigmidae. Members are small chalcidoid wasps that develop as parasitoids within oak galls induced by cynipid gall wasps. Two European species morphologically keyed to B. dorsalis have been introduced to North America: one clade found in New York, and another in the Pacific Northwest. These introductions represent the first documented cases of Bootanomyia establishment in North America.
Callirhytis
Callirhytis is a genus of gall wasps comprising more than 90 described species, all members of the family Cynipidae. These wasps are specialized herbivores that induce the formation of galls on oak trees (Quercus spp.) in North America. The genus exhibits complex life cycles with alternating sexual and asexual generations, often producing morphologically distinct galls. Callirhytis species are among the most extensively studied cynipids due to their ecological importance and the structural diversity of their galls.
Callirhytis balanopsis
Callirhytis balanopsis is a species of gall wasp in the family Cynipidae. The species induces galls on oak hosts, continuing the genus's well-documented association with Quercus species. Like other Callirhytis species, it exhibits a complex life cycle with alternating sexual and asexual generations that produce distinct gall types. The specific epithet 'balanopsis' references the acorn-like appearance of its galls.
Callirhytis carmelensis
Mottled Acorn Gall Wasp
A cynipid gall wasp endemic to California that induces distinctive galls on acorns of coast live oak (Quercus agrifolia) and interior live oak (Quercus wislizeni). The galls form at the acorn attachment point, often preventing normal nut development. The species produces a honeydew secretion that attracts other insects. Despite being described in 1922, it remains uncommon and poorly studied relative to other California oak gall wasps.
Callirhytis congregata
sausage flower gall wasp
Callirhytis congregata is a cynipid gall wasp native to California that induces distinctive galls on the catkins of three oak species: coast live oak (Quercus agrifolia), interior live oak (Quercus wislizeni), and canyon live oak (Quercus chrysolepis). The species was originally described by William Harris Ashmead in 1896 under the genus Andricus. It is considered locally common within its range. The galls are described as rugose, yellowish-brown woody swellings with multiple cells, appearing to grow from the tips of slender twigs with a long peduncle-like base.
Callirhytis ellipsoida
Callirhytis ellipsoida is a species of gall wasp in the family Cynipidae. Like other members of its genus, it induces the formation of galls on oak hosts. The species exhibits the typical complex life cycle of oak cynipids, with alternating sexual and asexual generations that produce morphologically distinct galls.
Callirhytis elliptica
Callirhytis elliptica is a species of gall wasp in the family Cynipidae. The species is known to induce galls on oak hosts, consistent with the genus's well-documented association with oaks. As with other members of Callirhytis, this species exhibits the complex life cycles typical of cynipid gall wasps, often involving alternating sexual and asexual generations that produce different gall forms. Specific details regarding the morphology of its galls and precise host oak species remain limited in published sources.
Callirhytis favosa
Honeycomb leaf gall wasp
Callirhytis favosa is a gall wasp in the family Cynipidae that induces distinctive honeycomb-patterned galls on oak leaves. The species exhibits the complex life cycle typical of many cynipids, with alternating sexual and asexual generations that produce different gall types on different oak tissues. The specific epithet 'favosa' refers to the honeycomb-like appearance of the galls.
Callirhytis flavipes
Callirhytis flavipes is a species of gall wasp in the family Cynipidae. Species in this genus are known to induce galls on oak trees (Quercus spp.). The genus Callirhytis is part of the tribe Cynipini, which comprises the oak gall wasps. Specific biological details for C. flavipes remain poorly documented in accessible literature.
Callirhytis frequens
Callirhytis frequens is a species of gall wasp in the family Cynipidae. Members of the genus Callirhytis are known to induce galls on oak species (Quercus). The species exhibits the complex life cycle typical of many cynipids, with alternating sexual and asexual generations that often produce morphologically distinct galls on different oak tissues or species. As with most Callirhytis species, detailed natural history information for C. frequens remains limited in published literature.
Callirhytis glandulus
Callirhytis glandulus is a species of gall wasp in the family Cynipidae. Like other members of the genus Callirhytis, this species induces the formation of galls on oak hosts (Quercus). The species was described by Beutenmüller in 1913. As with many Cynipidae, it likely exhibits an alternating generation life cycle with distinct sexual and asexual phases that produce different gall morphologies.
Callirhytis juvenca
Callirhytis juvenca is a species of gall wasp in the family Cynipidae. Like other members of its genus, it induces galls on oak hosts (Quercus species). The species exhibits the typical complex life cycle of cynipid gall wasps, with alternating sexual and asexual generations that often produce morphologically distinct galls. Specific details regarding its host associations and gall morphology remain limited in published literature.
Callirhytis lanata
Callirhytis lanata is a species of gall wasp in the family Cynipidae. It induces galls on oak species (Quercus), with specific host associations and gall morphology distinguishing it from congeners. The species exhibits the typical cynipid life cycle with alternating sexual and asexual generations that produce different gall forms.
Callirhytis perdens
Ruptured Twig Gall Wasp
Callirhytis perdens is a gall wasp in the family Cynipidae that induces distinctive stem galls on several oak species in California. Unlike many gall wasps where larvae develop entirely within attached galls, this species exhibits a unique life history where mature larval capsules are expelled from fissures in the gall and complete development on the ground. The species was formerly classified under the genus Andricus. It is considered locally abundant within its restricted range.
Callirhytis perfoveata
leaf ball gall wasp
Callirhytis perfoveata is a cynipid gall wasp endemic to California that induces distinctive spherical leaf galls on oak trees. Formerly classified as Andricus perfoveata, this species specifically targets coast live oak (Quercus agrifolia), interior live oak (Q. wislizeni), and occasionally California black oak (Q. kelloggii). The galls form embedded within leaf tissue, appearing as roughly spherical structures that emerge bright green and mature to brown.
Callirhytis pigra
oak midrib gall
A cynipid gall wasp that induces distinctive galls on oak leaves. The species exhibits the typical complex life cycle of oak gall wasps, with alternating sexual and asexual generations that produce different gall morphologies on different oak tissues. The common name refers to the gall's position along the leaf midrib.
Callirhytis piperoides
Callirhytis piperoides is a gall wasp in the family Cynipidae. Like other members of its genus, it induces gall formation on oak hosts (Quercus species). The species was described by Bassett in 1900. As with many Cynipidae, it exhibits a complex life cycle involving alternating generations that may produce different gall types on different plant tissues.
Callirhytis pulchra
Callirhytis pulchra is a species of gall wasp in the family Cynipidae, first described by Bassett in 1890. Like other members of its genus, this species induces distinctive galls on oak trees (Quercus spp.). The species exhibits the complex life cycles typical of Cynipidae, often involving alternating sexual and asexual generations that produce different gall types on different plant tissues. As an oak specialist, it contributes to the remarkable diversity of gall-forming insects associated with this tree genus in North America.
Callirhytis quercusbatatoides
Southern Live Oak Stem Gall Wasp
Callirhytis quercusbatatoides is a cynipid gall wasp that induces stem galls on Southern live oak (Quercus virginiana) and related oak species. The species exhibits the complex life cycle typical of many oak gall wasps, with alternating sexual and asexual generations that produce morphologically distinct galls. The specific epithet 'quercusbatatoides' references the gall's resemblance to a sweet potato (batata). The species is well-documented in the southeastern United States where its host oaks are native.
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 quercussuttoni
Gouty Stem Gall Wasp
Callirhytis quercussuttoni is a gall wasp in the family Cynipidae that induces galls on stems of oaks in the red oak group (section Lobatae). The species is restricted to the west coast of North America, where it has been documented on coast live oak (Quercus agrifolia) and interior live oak (Q. wislizeni). Its common name refers to the swollen, irregular galls it produces on host stems.
Callirhytis quercusventricosa
Callirhytis quercusventricosa is a species of gall wasp in the family Cynipidae, known for inducing galls on oaks (Quercus). The species exhibits the complex life cycle typical of Cynipini, with alternating sexual and asexual generations that produce distinct gall morphologies on different oak tissues. It is one of numerous oak-galling species in the large genus Callirhytis.
Callirhytis rugulosa
Callirhytis rugulosa is a species of gall wasp in the family Cynipidae. Like other members of this family, it induces the formation of galls on host plants, though specific gall morphology and host associations for this species are not well documented in available sources. The species belongs to a genus predominantly associated with oak galls.
Callirhytis seminator
Wool Sower, Wool Sower Gall Wasp
Callirhytis seminator, commonly known as the wool sower, is a gall wasp that induces distinctive cotton-like galls on white oak trees. The species exhibits a complex alternating life cycle involving two different gall types, though the alternate gall form remains unidentified. Adults are small, dark brown wasps approximately 3 mm in length. The species poses no threat to humans or oak tree health.
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.
Callirhytis serricornis
kernel flower gall wasp
Callirhytis serricornis is a cynipid gall wasp endemic to California that induces distinct bottle- or vase-shaped galls on oak trees. The species exhibits alternating generations with different gall phenotypes: first-generation galls are brown, while second-generation galls are red and green. It is restricted to two host oak species in the western United States.
Callirhytis tubicola
Callirhytis tubicola is a species of gall wasp in the family Cynipidae. Like other members of its genus, it induces galls on oak trees. The species exhibits the complex life cycle typical of oak gall wasps, with alternating sexual and asexual generations that produce distinct gall morphologies on different oak tissues.
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.
Cynipini
Oak Gall Wasps
Cynipini is the largest tribe of gall wasps in the family Cynipidae, comprising approximately 936 to 1,000 described species. Members are commonly known as oak gall wasps due to their specialized association with oaks (Quercus) and other Fagaceae. The tribe is primarily distributed in the Holarctic region, with significant diversity also in Mexico and Central America. Cynipini species induce structurally diverse galls on various oak tissues including leaves, buds, branches, petioles, catkins, acorns, and roots. Most species exhibit cyclical parthenogenesis, alternating between sexual and asexual generations that often produce different gall morphotypes on the same or different host tissues.
Cynips
oak gall wasps
Cynips is a genus of gall wasps comprising approximately 39 species, all associated with oak trees (Quercus spp.). The genus includes the well-known common oak gall wasp (C. quercusfolii), which induces spherical galls on oak leaf undersides. Species in this genus exhibit heterogony, alternating between sexual and asexual generations that typically produce morphologically distinct galls. The genus was established by Linnaeus in 1758 and remains taxonomically stable, though some former members (such as Antron) have been reinstated as separate genera.
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 potentillae
cinquefoil bud gall wasp
Diastrophus potentillae is a gall wasp in the family Cynipidae that induces bud galls on cinquefoil plants. The species is known from eastern North America, with records from Canada and the northeastern United States. It has been documented on Potentilla canadensis and P. simplex as host plants.
Diplolepis
gall wasps, rose gall wasps
Diplolepis is a genus of gall-inducing wasps in the family Diplolepididae, most commonly associated with roses (Rosa spp.). These small wasps are notable for inducing complex, often conspicuous galls on their host plants through chemical manipulation of plant tissues. The genus includes both sexual and parthenogenetic species, with some like D. rosae reproducing primarily by thelytokous parthenogenesis. Diplolepis species exhibit intricate life cycles involving alternation between sexual and agamic generations, and their galls support diverse communities of parasitoids and inquilines.
Diplolepis gracilis
Diplolepis gracilis is a species of gall wasp in the family Diplolepididae, first described by Ashmead in 1897. Like other members of its genus, it induces the formation of galls on host plants, likely within the rose family (Rosaceae) given the genus's strong association with this plant group. The species is recorded from multiple provinces across Canada including Alberta, British Columbia, Manitoba, and Ontario. As with most Diplolepis species, it exhibits a complex life cycle involving an alternation between sexual and parthenogenetic generations.
Diplolepis ignota
gall wasp
Diplolepis ignota is a gall wasp in the family Cynipidae that induces spherical, single-chambered galls on the leaves of wild rose species (Rosa). The galls serve as both shelter and food source for developing larvae. Multiple galls frequently coalesce into irregularly rounded clusters. Adults emerge from galls the summer following gall initiation. The species has been reported throughout most of the continental United States and in parts of central Canada.
Diplolepis nervosa
Spiked Pea Gall Wasp
Diplolepis nervosa is a gall wasp in the family Diplolepididae that induces distinctive spiked pea galls on wild roses (Rosa species). Like other members of its genus, it exhibits an alternation of generations with both sexual and parthenogenetic phases. The species is native to Europe and has been introduced to North America, where it has become established. The galls it produces are among the most recognizable of rose galls due to their characteristic spiny, pea-like appearance.
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 rosaefolii
Diplolepis rosaefolii is a gall wasp in the family Cynipidae that induces distinctive lenticular (lens-shaped) galls on the leaves of rose plants across Canada. The species exhibits an alternation of generations life cycle typical of cynipid wasps, with a bisexual spring generation producing the visible galls and an agamic (asexual) winter generation of wingless females. In Ontario and Quebec, it is primarily associated with native Rosa acicularis, though populations have been documented on the cultivated hybrid rugosa shrub rose 'Thérèse Bugnet'. The galls support a diverse component community including multiple parasitoid wasp species and inquilines.