Oak-gall
Guides
Acraspis
Acraspis is a genus of gall wasps in the family Cynipidae. Species in this genus induce distinctive galls on oak leaves (Quercus spp.), including the jewel oak gall and oak pea gall. The genus exhibits specialized host associations with oaks and has been documented to employ spacing strategies that reduce parasitoid attack rates.
Acraspis pezomachoides
Acraspis pezomachoides is a gall-inducing cynipid wasp in the family Cynipidae. Like other members of the genus Acraspis, it induces distinctive galls on oak trees (Quercus spp.). The species was described by Osten Sacken in 1862. Specific gall morphology and host associations for this species are not well documented in the provided sources, though the genus is known for producing structurally complex galls on white oaks.
Acraspis prinoides
Acraspis prinoides is a species of gall wasp in the family Cynipidae. Like other members of its genus, it induces characteristic galls on oak trees. The species is part of a diverse group of Cynipidae that exhibit highly specialized relationships with their host plants, with each species typically inducing galls of distinctive morphology on specific oak species or groups.
Acraspis quercushirta
jewel oak gall wasp
Acraspis quercushirta, the jewel oak gall wasp, is a North American cynipid wasp that induces distinctive, detachable galls on white oak leaves. The species exhibits a complex life cycle with alternating sexual and asexual generations, each producing morphologically different galls. The sexual generation forms the namesake "jewel" galls—oval, faceted structures ranging from white to brown that detach and fall with leaves in autumn. Molecular studies have confirmed its conspecific status with A. macrocarpae, which was previously considered a separate species.
Acraspis villosa
Acraspis villosa is a gall-forming wasp in the family Cynipidae. It induces galls on bur oak (Quercus macrocarpa). The species has been documented in Canada and the United States. Molecular studies have confirmed alternate sexual and asexual generations using DNA sequencing of cytb and ITS2 markers.
Amphibolips
Amphibolips is a genus of gall wasps in the family Cynipidae, first described by Reinhard in 1865. The genus contains approximately 57 described species, with additional undescribed species known. All members are native to the Americas and are specialized gall inducers, primarily on oaks (Quercus spp.).
Amphibolips acuminata
Fusiform Oak Apple Gall Wasp
Amphibolips acuminata is a species of gall wasp in the family Cynipidae, commonly known as the Fusiform Oak Apple Gall Wasp. The species induces distinctive galls on oak trees, specifically forming fusiform (spindle-shaped) oak apple galls. As with other members of the genus Amphibolips, this species has an alternation of generations with distinct sexual and asexual forms that produce different gall types. The species is associated with oaks in the genus Quercus and has been documented across a broad geographic range in North America.
Amphibolips confluenta
spongy oak apple gall wasp
Amphibolips confluenta, commonly known as the spongy oak apple gall wasp, is a species of gall wasp in the family Cynipidae. The species induces characteristic galls on oak trees (Quercus spp.) and has been recorded from multiple oak host species across eastern North America. Its range extends from Ontario and Quebec in Canada through much of the eastern United States.
Amphibolips cookii
Oak Apple Gall Wasp
Amphibolips cookii is a cynipid gall wasp that induces the formation of oak apple galls on oak trees. The species is widely distributed in North America and has been documented extensively through community science observations. Its life cycle involves an alternation of generations between sexual and asexual forms, a trait common among Cynipidae but with specific host associations for this species. The wasp itself is small and inconspicuous; its primary visibility comes from the distinctive galls it produces on oak foliage.
Amphibolips ellipsoidalis
Amphibolips ellipsoidalis is a species of gall wasp in the family Cynipidae. Members of this genus are known to induce galls on oak trees (Quercus species). The specific epithet 'ellipsoidalis' refers to the elliptical shape of the gall structure it produces. This species is part of a diverse radiation of cynipid wasps specialized on oaks in North America.
Amphibolips femoratus
A species of gall wasp in the family Cynipidae, originally described by Ashmead in 1887 as Andricus femoratus before transfer to Amphibolips. Like other members of this genus, it induces galls on oaks (Quercus spp.). The species is documented from limited observations, with most records from North America.
Amphibolips fusus
Amphibolips fusus is a species of gall wasp in the family Cynipidae, described by Alfred Kinsey in 1937. The species belongs to a genus known for inducing galls on oak trees (Quercus spp.). It has been documented from central Mexico, specifically in Ciudad de México and Zacatecas states. Like other members of Cynipidae, it likely has a complex life cycle involving both sexual and asexual generations, though specific details for this species remain poorly documented.
Amphibolips gainesi
Amphibolips gainesi is a species of gall wasp described by Bassett in 1900. It belongs to the family Cynipidae, a group of wasps known for inducing galls on oak trees. The genus Amphibolips is associated with oak galls, though specific details about this species' biology remain limited in published literature.
Amphibolips globulus
Amphibolips globulus is a species of gall wasp in the family Cynipidae, described by Beutenmüller in 1909. The species is associated with oak galls, a characteristic trait of the genus Amphibolips. It is part of a diverse radiation of cynipid wasps that induce plant tissue modifications to serve as larval habitat and food source.
Amphibolips ilicifoliae
Amphibolips ilicifoliae is a species of gall wasp in the family Cynipidae that induces galls on oak leaves. It is one of numerous Amphibolips species associated with oaks in North America. The species is distinguished by its specific host association with certain oak groups and the morphology of the galls it produces. Like other cynipid gall wasps, it has a complex life cycle involving both sexual and asexual generations, though details specific to this species remain incompletely documented.
Amphibolips murata
Amphibolips murata is a species of gall wasp in the family Cynipidae. Like other members of its genus, it induces the formation of galls on oak trees (Quercus species). The species is documented from multiple observations, though detailed biological studies remain limited.
Amphibolips nubilipennis
translucent oak gall wasp
Amphibolips nubilipennis is a gall wasp in the family Cynipidae that induces distinctive succulent galls on oak trees. The species exhibits a complex life cycle with alternating sexual and asexual generations, each producing different gall types. The translucent oak gall formed by the sexual generation accumulates exceptionally high concentrations of malic acid, creating extremely acidic tissue conditions. This species has been documented across eastern North America and serves as a model organism for studying gall chemistry and plant-insect interactions.
Amphibolips quercuscoelebs
Amphibolips quercuscoelebs is a species of gall wasp in the family Cynipidae. It induces galls on oak trees (Quercus spp.), specifically associated with the host species suggested by its specific epithet. Like other members of the genus Amphibolips, this species exhibits a complex life cycle with alternating sexual and asexual generations, though detailed documentation for this particular species remains limited. The species has been documented through a small number of observations, indicating it may be uncommon or underreported.
Amphibolips quercusfuliginosa
Amphibolips quercusfuliginosa is a species of gall wasp in the family Cynipidae. It induces galls on oak species (Quercus), with the specific epithet referencing the sooty or dark appearance of the gall structures. The species belongs to a genus known for producing complex, often spherical galls on oaks. It is part of the diverse North American cynipid fauna associated with white oaks.
Amphibolips quercusinanis
larger empty oak apple wasp
Amphibolips quercusinanis is a gall wasp in the family Cynipidae that induces large, apple-sized galls on leaves of red oak species in central and eastern North America. The species is notable for producing conspicuous, hollow galls that become brittle and empty after the adult wasp emerges. It has been widely documented through citizen science observations.
Amphibolips quercusjuglans
Acorn Plum Gall Wasp
Amphibolips quercusjuglans, commonly known as the acorn plum gall wasp, is a cynipid gall wasp that induces distinctive plum-like galls on acorns of oak trees (Quercus spp.). The species is part of a large radiation of gall-forming wasps specialized on oaks in North America. Its galls are among the most visually striking of oak galls, developing on the cupule or acorn itself rather than on leaves or stems.
Amphibolips quercusostensackenii
Small Oak Apple Gall Wasp
Amphibolips quercusostensackenii is a gall wasp in the family Cynipidae that induces distinctive galls on red oak leaves. The species was reclassified from Andricus to Amphibolips in 2002 based on adult morphology. It is distributed throughout eastern North America.
Amphibolips quercusracemaria
Amphibolips quercusracemaria is a species of gall wasp in the family Cynipidae, first described by Ashmead in 1881. The specific epithet "quercusracemaria" indicates an association with oak (Quercus), likely inducing galls on catkins or inflorescences. Like other members of the genus Amphibolips, this species is part of the diverse North American cynipid fauna specialized on oaks.
Amphibolips quercusrugosa
Amphibolips quercusrugosa is a species of gall wasp in the family Cynipidae. It is known for inducing galls on oak trees (Quercus species), specifically associated with the wrinkled oak or related species. The species was described by William Beutenmüller in 1909. As with other Amphibolips species, it has a complex life cycle involving both sexual and asexual generations that alternate between different gall types on oaks.
Amphibolips quercusspongifica
Summer Sponge Apple Gall Wasp
Amphibolips quercusspongifica is a gall wasp in the family Cynipidae that induces distinctive sponge-like galls on oak trees. The species is known for producing 'spongy apple galls' on various Quercus species, with the common name referencing both the texture and seasonal timing of gall development. Like other Cynipidae, it has a complex life cycle likely involving alternate generations, though specific details remain incompletely documented. The species is relatively poorly known, with limited observational records.
Andricus balanella
Andricus balanella is a species of gall wasp in the family Cynipidae, a group renowned for inducing distinctive plant galls on oak species. Like other members of the genus Andricus, this species forms intimate associations with oaks (Quercus spp.), with females laying eggs in plant tissues to initiate gall development. The resulting galls serve as both shelter and food source for the developing larva. The specific gall morphology and host oak species for A. balanella are not well documented in available sources, though the genus is characterized by highly species-specific gall forms.
Andricus brunneus
Clustered Gall Wasp
Andricus brunneus is a small oak gall wasp found along the Pacific Coast of North America. Only females of this species are known to exist, indicating reproduction occurs through parthenogenesis. The species induces distinctive round galls on white oak leaves, particularly blue oaks (Quercus douglasii). Adults emerge in autumn.
Andricus burnetti
Andricus burnetti is a species of gall wasp in the family Cynipidae, a group renowned for inducing diverse and structurally complex galls on oak trees. As a member of the genus Andricus, this species participates in the intricate life cycle characteristic of cynipid wasps, where females lay eggs in oak tissues and the developing larvae secrete substances that redirect plant growth to form specialized galls. The species was described by Burnett, for whom it is named. Like many Andricus species, it likely exhibits host specificity to particular oak species, though detailed biological accounts remain limited in published literature.
Andricus capillatus
Andricus capillatus 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 trees (Quercus spp.), with each cynipid species producing a distinct gall morphology specific to its biology. The genus Andricus is one of the most diverse genera of gall wasps, with numerous species specialized on different oak species and plant tissues.
Andricus chinquapin
Small Oak Spindle Gall Wasp
Andricus chinquapin is a cynipid gall wasp that induces distinctive spindle-shaped galls on oaks, particularly species in the white oak group including Quercus muhlenbergii (chinquapin oak). The species was described by Fitch in 1859. Like other Andricus species, it exhibits high host specificity, with galls forming on leaf tissues where larvae develop inside the protective structure. The adult wasps are tiny, typically measuring only a few millimeters in length.
Andricus chrysolepidicola
Irregular Spindle Gall Wasp, irregular-spindle gall wasp
Andricus chrysolepidicola is a cynipid gall wasp that induces distinctive stem galls on several oak species in western North America. The species exhibits a complex heteroecious life cycle with alternating generations: first-year unisexual wasps produce irregular spindle-shaped stem galls, while second-year bisexual wasps induce bud galls. The species is primarily documented from California but has been recorded elsewhere along the Pacific coast and eastward to Nevada.
Andricus coconinoensis
Andricus coconinoensis is a species of cynipid gall wasp described in 2021. As a member of the family Cynipidae, it induces characteristic galls on oak host plants. The specific epithet references Coconino County, Arizona, suggesting a southwestern United States distribution. Like other Andricus species, it exhibits intimate host plant specialization typical of this diverse gall wasp genus.
Andricus confertus
Convoluted Gall Wasp
Andricus confertus is a cynipid gall wasp endemic to California that induces distinctive pink, brain-like clustered galls on the underside of valley oak (Quercus lobata) leaves along the midrib. The species reproduces parthenogenetically, with female larvae initiating gall formation in summer and adults emerging the following spring. The galls are composite structures formed by multiple individual galls growing in close proximity.
Andricus cooki
Andricus cooki is a species of cynipid gall wasp described in 2021. As a member of the genus Andricus, it is an oak-associated gall wasp that induces characteristic galls on Quercus species. The genus Andricus is one of the most diverse genera of gall wasps, with each species typically producing distinct gall morphologies on specific oak hosts. Like other Andricus species, this wasp likely has a complex life cycle involving both sexual and asexual generations, though specific details for this recently described species remain to be documented.
Andricus coortus
Andricus coortus is a species of cynipid gall wasp described by Weld in 1947. It belongs to the genus Andricus, one of the most diverse genera of gall wasps associated with oaks. Species in this genus are known for inducing characteristic galls on various parts of oak trees, with each species typically producing a distinct gall morphology on specific host tissues. Like other Andricus species, A. coortus likely exhibits complex life cycles involving alternation between sexual and asexual generations on different oak tissues, though specific details for this species remain poorly documented.
Andricus coquilletti
Andricus coquilletti is a species of gall wasp in the family Cynipidae, a group renowned for inducing characteristic plant galls on oaks. Like other members of its genus, this species has an intimate ecological relationship with oak trees (Quercus spp.), where females deposit eggs into developing leaf tissue using their ovipositor, triggering the formation of protective galls that house developing larvae. The species is part of one of the most diverse radiations of gall-forming insects, with each cynipid species typically producing a distinct gall morphology on specific host tissues.
Andricus coronus
Andricus coronus is a cynipid gall wasp in the family Cynipidae. Like other members of this genus, it induces characteristic galls on oak trees (Quercus spp.), serving as both shelter and food source for its developing larvae. The species exemplifies the highly specialized host relationships typical of gall wasps, where each species typically induces a distinct gall form on specific host plant tissues.
Andricus dimorphus
Clustered Midrib Gall Wasp
Andricus dimorphus, commonly known as the clustered midrib gall wasp, is a cynipid wasp that induces distinctive galls on oak leaves. The species forms clusters of up to 50 globular, red-brown galls along the midrib on the abaxial (underside) surface of white oak leaves, beginning in late summer. Adults emerge from galls the following year. The species was first described by William Beutenmuller in 1913 as Cynips dimorphus and later transferred to Andricus via the genus Adleria.
Andricus foliaformis
Andricus foliaformis is a species of cynipid gall wasp in the family Cynipidae, described by Gillette in 1888. Like other members of the genus Andricus, this species induces characteristic galls on oak hosts (Quercus spp.). The specific epithet "foliaformis" suggests a leaf-associated gall morphology. Cynipid gall wasps in this genus typically exhibit complex life cycles involving alternating sexual and asexual generations, with each generation often producing distinct gall forms on different plant tissues.
Andricus lustrans
Andricus lustrans is a species of cynipid gall wasp described by Beutenmuller in 1913. Like other members of the genus Andricus, this species induces characteristic galls on oak trees (Quercus spp.), with gall formation triggered by chemical secretions from the developing larva that manipulate plant hormones. The specific gall morphology and host associations distinguish it from related species. Adult wasps emerge from galls to reproduce and initiate new gall generations.
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 murtfeldtae
Andricus murtfeldtae 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 trees (Quercus spp.). The wasp exhibits the typical life cycle of gall wasps, with females laying eggs in oak tissue and larvae developing within the protective gall structure. Specific details regarding its host associations and gall morphology are not well documented in available sources.
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.
Andricus opertus
Fimbriate Gall Wasp
Andricus opertus is a cynipid gall wasp that induces distinctive galls on California oaks. The species exhibits alternation of generations, with bisexual and unisexual forms producing different gall types. The bisexual generation creates elongate, spiky leaf galls, while the unisexual generation forms aborted bud galls. This species is part of the highly diverse Andricus genus, which contains numerous oak-associated gall wasps.
Andricus pedicellatus
hair stalk gall wasp
Andricus pedicellatus, commonly known as the hair stalk gall wasp, is a cynipid wasp that induces distinctive long, spindly leaf galls on blue oaks (Quercus douglasii). The species is fairly common along the Pacific coast of North America. Like other members of the genus Andricus, it exhibits high host specificity, attacking only one or a few closely related oak species.
Andricus pisiformis
Andricus pisiformis is a species of cynipid gall wasp in the tribe Cynipini, first described by Beutenmüller in 1911. Like other members of its genus, this wasp induces characteristic galls on oak trees (Quercus spp.). The species name 'pisiformis' refers to the pea-like shape of the galls it produces. As with many Andricus species, it exhibits a complex life cycle typically involving alternation between sexual and asexual generations on different oak hosts or plant parts, though specific details for this species remain incompletely documented.
Andricus quercusfoliatus
leafy oak gall wasp
Andricus quercusfoliatus, commonly known as the leafy oak gall wasp, is a species of cynipid gall wasp that induces distinctive galls on oak leaves. Like other members of the family Cynipidae, this wasp manipulates plant tissue development through chemical secretions, causing the host oak to form a specialized structure that provides shelter and nutrition for the developing larva. The species is part of the highly diverse Andricus genus, which contains numerous oak-associated gall wasps, each typically specialized to specific host species or oak groups. The common name 'leafy' refers to the gall's location on leaves rather than twigs or other plant parts.
Andricus quercusformosus
Andricus quercusformosus is a species of cynipid gall wasp in the family Cynipidae. The species was originally described by Bassett in 1864 under the basionym Cynips quercusformosa. Like other members of the genus Andricus, this species is associated with oak trees (Quercus spp.) as host plants. The specific epithet "quercusformosus" derives from Latin, combining "quercus" (oak) with "formosus" (beautiful), likely referring to the appearance of the galls it produces. The species belongs to the highly diverse gall wasp family Cynipidae, which contains thousands of species that form characteristic galls on various plant parts.
Andricus quercusfrondosus
Oak Rosette Gall Wasp
Andricus quercusfrondosus is a cynipid gall wasp that induces distinctive rosette-shaped galls on the leaves of oak trees. As a member of the highly diverse genus Andricus, this species exemplifies the intimate host-plant specialization characteristic of gall-forming wasps. The galls provide shelter and food for the developing larva, which manipulates plant growth hormones to create this specialized structure. Like many Cynipidae, this species has a complex life cycle often involving alternation between sexual and asexual generations on different host tissues or related oak species.
Andricus quercuspetiolicola
Oak Petiole Gall Wasp
Andricus quercuspetiolicola is a species of cynipid gall wasp that induces distinctive galls on white oaks (Quercus alba). The species name reflects its biology: 'quercus' for oak and 'petiolicola' indicating its habit of forming galls on leaf petioles and midribs. Adult wasps are small and inconspicuous, while the galls they produce are the most visible sign of their presence. Like other Andricus species, this wasp has a complex life cycle typically involving alternation between sexual and asexual generations on different oak tissues, though specific details for this species remain incompletely documented.