Gall-wasp
Guides
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.
Andricus quercusstrobilanus
lobed oak gall wasp, pine cone oak gall wasp
Andricus quercusstrobilanus is a gall wasp in the family Cynipidae that induces distinctive cone-shaped galls on white oaks in North America. The species name references both its oak host ('quercus') and the strobilus-like (cone-shaped) structure of the gall it produces. The galls are sometimes called 'pine cone oak galls' due to their appearance. Adults of this species have not been formally described.
Andricus reticulatus
Andricus reticulatus 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. Cynipid gall wasps are highly specialized insects with intimate evolutionary relationships with their host plants, typically forming species-specific gall structures that serve as both shelter and food source for developing larvae. The genus Andricus is one of the most diverse within the Cynipidae, with numerous species associated with various oak species.
Andricus robustus
Andricus robustus 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 specific gall morphology and host associations of A. robustus have not been extensively documented in the available literature. The species follows the typical cynipid life cycle involving an alternation of generations between sexual and asexual forms, though detailed studies of its biology remain limited.
Andricus sessilum
Andricus sessilum is a species of gall wasp in the family Cynipidae, a group known for inducing distinctive plant growths called galls on oak trees (Quercus spp.). Like other members of the genus Andricus, this species exhibits high host specificity, with females laying eggs in oak tissues to initiate gall formation. The developing larva secretes chemical signals that manipulate plant growth, creating a specialized structure that provides both food and shelter. Cynipid gall wasps are among the most diverse gall-forming insects, with each species typically producing a characteristic gall morphology on specific host plants or plant parts.
Andricus stellulus
stellar gall wasp
Andricus stellulus is a gall-inducing cynipid wasp that forms distinctive stellar galls on oak leaves. The species is known from arid regions of the southwestern United States, particularly the Mojave Desert of California, where it induces small, uniquely structured galls on scrub oak and shrub live oak. The galls consist of thin, hair-like stalks topped with toothed cups, representing one of the more architecturally unusual gall forms among the highly diverse Cynipidae.
Andricus stropus
leafy-wreath gall
Andricus stropus is a species of cynipid gall wasp in the family Cynipidae that induces distinctive galls on oak trees. The species is part of the highly diverse Andricus genus, which contains numerous oak-associated gall wasps, each producing characteristic gall structures. Like other cynipids, A. stropus has a complex life cycle involving manipulation of plant tissue through chemical secretions that redirect host oak growth patterns. The species is known from observations primarily in North America.
Andricus texanus
Andricus texanus is a species of gall wasp in the family Cynipidae, a diverse group of insects that induce characteristic growths on oak trees. Like other members of its genus, this species manipulates plant tissue to form specialized structures that provide shelter and food for developing larvae. The specific gall morphology and host associations distinguish it from related Andricus species.
Andricus tubularius
A cynipid gall wasp in the genus Andricus that induces distinctive galls on oak hosts. Like other members of this large and diverse genus, this species exhibits high host specificity and complex life cycles typical of oak gall wasps. The specific gall morphology and exact host associations for this species require further documentation.
Andricus vacciniifoliae
Golden Oak Apple Gall Wasp, Golden Oak Apple Wasp
Andricus vacciniifoliae is a gall-forming cynipid wasp native to the west coast of North America. The species creates distinctive stem galls on huckleberry oak (Quercus vacciniifolia) and canyon live oak (Quercus chrysolepis). The galls are colorful and fruit-like in appearance, often leading to misidentification as actual fruit. The wasp has been reclassified from Andricus to Trichoteras in some taxonomic treatments, though both names remain in use.
Andricus weldi
Andricus weldi is a species of cynipid gall wasp in the family Cynipidae. Like other members of this diverse family, it induces the formation of specialized plant galls on oak hosts. The species was named in honor of Lewis H. Weld, a prominent American cynipidologist who authored foundational works on gall wasps of the eastern United States. Specific details regarding its gall morphology, host associations, and biology remain limited in the available literature.
Andricus wheeleri
Andricus wheeleri is a species of gall wasp in the family Cynipidae. Like other members of this genus, it induces distinctive gall formations on oak host plants. The species is part of a highly diverse radiation of cynipid wasps that have evolved intimate associations with Quercus species. Specific details regarding its gall morphology and host relationships are not well documented in the available literature.
Antistrophus
Antistrophus is a genus of gall wasps in the family Cynipidae containing approximately 10 species, all restricted to the Nearctic region. Species induce galls on herbaceous plants in four Asteraceae genera: Silphium, Lygodesmia, Chrysothamnus, and Microseris. The genus was first described by Benjamin Walsh in 1869. Some species exhibit complex chemical ecology, using host plant volatile monoterpenes as olfactory cues for mate location.
Antistrophus
An undescribed species in the genus Antistrophus, a group of cynipid gall wasps that induce distinctive galls on Asteraceae host plants. Members of this genus are typically monophagous, with each species associated with a single host plant species. The specific epithet reference to 'laciniatum' suggests association with Silphium laciniatum (compass plant), though this remains to be confirmed. The species has not been formally described in the scientific literature.
Antistrophus
rosinweed stem gall wasp
An undescribed species of cynipid gall wasp in the genus Antistrophus that induces distinctive stem-cluster galls on Silphium perfoliatum (cup plant). Like other Antistrophus species, it likely produces only female wasps through parthenogenesis, with adults emerging in fall to lay eggs in host plant stems. The galls provide shelter and food for developing larvae.
Antistrophus
undescribed Silphium flower gall wasp
An undescribed species of gall wasp in the genus Antistrophus that induces flower galls on Silphium species, particularly in tallgrass prairie ecosystems. The wasp manipulates plant tissue to form protective galls that house developing larvae. This species represents part of a complex of Antistrophus wasps specialized on Silphium host plants, with distinct species targeting stems versus flowers.
Antistrophus jeanae
Antistrophus jeanae is a gall wasp in the family Cynipidae, described in 2004 by Tooker and Hanks. Like other members of the genus Antistrophus, this species is likely associated with specific host plants in the Asteraceae family, though detailed natural history information remains limited. The species is known from a small number of observations, suggesting it may be relatively rare or underreported. It belongs to a genus characterized by stem-galling habits on composite plants.
Antistrophus laciniatus
Antistrophus laciniatus is a gall wasp in the family Cynipidae that induces stem galls on Silphium integrifolium (wholeleaf rosinweed), a prairie plant in the Asteraceae. The species was described by Gillette in 1891 and is one of several Antistrophus species associated with Silphium hosts. New host plant and distribution records have been documented in recent years.
Antistrophus pisum
Antistrophus pisum is a species of gall wasp in the family Cynipidae. It is a synonym of Antistrophus lygodesmiaepisum, a monophagous cynipid wasp that induces pea-like stem galls on the rush skeletonplant (Lygodesmia juncea). The species occurs in the Loess Hills region of western Iowa and extreme northwestern Missouri, where its host plant persists as a hypsithermal relict in hilltop prairie remnants. The galls are solid, succulent structures that exude latex-like sap when damaged.
Antistrophus rufus
Antistrophus rufus is a gall wasp in the family Cynipidae that induces galls in flowering stems of prairie perennials in the genus Silphium. It is part of the A. rufus species complex, which was revised from three to five species based on morphological, ecological, and DNA barcode data. The species exhibits a unique chemical ecology: males and females use host plant volatiles as olfactory cues for mate location and host selection. Gall induction alters monoterpene enantiomer ratios in host stems, creating species-specific chemical signals.
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.
Antron douglasii
Spined Turban Gall Wasp
A cynipid gall wasp that induces distinctive spined turban galls on oak leaves. The galls are characterized by their fleshy, pink to reddish appearance with bristly projections. This species is part of the highly diverse oak gall wasp fauna of western North America. The wasp manipulates plant tissue development through chemical cues, though the precise mechanism remains unknown.
Antron quercusechinus
urchin gall wasp
Antron quercusechinus is a gall-inducing cynipid wasp that induces the distinctive 'urchin gall' on oak trees. The gall is spherical, approximately 1.5 cm in diameter, and covered with prominent spines that give it a sea urchin-like appearance. The species primarily targets blue oaks (Quercus douglasii) but has been observed on other white oaks. Heavy infestations can produce thousands of galls on individual trees.
Antron quercusnubila
Antron quercusnubila is a gall-inducing cynipid wasp native to the southwestern United States. The species exhibits an alternating sexual and asexual generation cycle, a trait confirmed through molecular analysis of cytb and ITS2 sequences. Like other members of the Cynipidae, this wasp manipulates oak host tissue to form protective galls that shelter and nourish developing larvae.
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 clavuloides
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.
Atrusca quercuscentricola
Spotted Oak Apple Gall Wasp
Atrusca quercuscentricola is a cynipid gall wasp that induces distinctive colorful galls on the leaves of post oak (Quercus stellata). The galls are particularly notable for their bright coloration and the presence of a visible adult emergence hole upon maturation. Like other cynipid gall wasps, the female lays eggs in leaf tissue using her ovipositor, and the developing larvae secrete plant growth hormones that cause the plant to form a specialized gall structure. The larva develops inside this gall, feeding on the plant tissue, before emerging as an adult through a chewed exit hole.
Atrusca trimaculosa
Woollybear Gall Wasp
Atrusca trimaculosa, commonly known as the woollybear gall wasp, is a cynipid gall wasp that induces distinctive round, hairy galls on oak leaves. The galls are 3–4 mm wide, covered in stiff hairs, and typically clustered on leaf surfaces. Only females of this species are known, suggesting reproduction may occur through parthenogenesis. The species is associated with several oak species including valley oak, blue oak, and Oregon oak.
Atrusca unica
Atrusca unica is a species of cynipid gall wasp in the family Cynipidae. Like other gall wasps, it induces the formation of specialized plant structures called galls on its host plant. The genus Atrusca is known for producing colorful, prominent leaf galls on oaks (Quercus spp.). This species appears to be relatively well-documented with 227 observations on iNaturalist, suggesting it is not exceptionally rare, though specific details about its biology remain limited in the provided sources.
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.
Aulacidea podagrae
Aulacidea podagrae is a species of gall wasp in the family Cynipidae. Like other members of its genus, it induces gall formation on host plants. The species was described by Bassett in 1890. It belongs to a group of cynipid wasps that serve as hosts for parasitoid wasps such as Eupelmus messene.
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.
Bassettia
Bassettia is a genus of gall wasps in the family Cynipidae, restricted to North America. The genus was established by William Harris Ashmead in 1887, named in honor of H. F. Bassett, an amateur entomologist who contributed significantly to the study of gall wasps. As of 2007, the genus comprises nine recognized species distributed across the United States from Connecticut to California, with one species extending into Panama. These wasps induce galls on oak trees (Quercus species), with each species typically associated with specific host plants and geographic regions.
Bassettia flavipes
Bassettia flavipes is a gall wasp in the family Cynipidae that induces galls on oaks, particularly Quercus macrocarpa (bur oak). This species exhibits an alternation of generations between sexual and asexual forms, a trait now confirmed through molecular data. It was originally described from the sexual generation by Gillette in 1889 and was later transferred from the genus Neuroterus to Bassettia based on genetic and morphological evidence. The species is distributed across the northern United States and southern Canada.
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.
Belonocnema treatae
Belonocnema treatae is a cynipid gall wasp species associated with live oaks in the southeastern United States. It exhibits an alternating sexual and asexual generation life cycle, with each generation forming distinct gall types on different parts of the host plant. The species has served as a model organism for studies of speciation and ecological interactions. It was first described by Gustav Leopold Mayr in 1881 based on specimens collected by naturalist Mary Treat in Florida.
Bruchophagus
seed chalcid, gall wasp
Bruchophagus is a genus of chalcid wasps in the family Eurytomidae. Species within this genus are primarily seed-feeders, developing in the seeds of plants in the Fabaceae family, though some species form galls on citrus or other hosts. The genus has a cosmopolitan distribution and includes economically significant pests such as the alfalfa seed chalcid (B. roddi) and citrus gall wasp (B. fellis). Recent phylogenomic studies indicate the genus is paraphyletic.
Burnettweldia californicordazi
Burnettweldia californicordazi is a species of oak cynipid gall wasp described in 2021 as the type species of the new genus Burnettweldia. The genus was established to accommodate five Nearctic species previously assigned to other genera or newly described. As a member of tribe Cynipini, this species induces galls on oak trees (Quercus spp.). The species name references California, indicating the geographic region of its type locality.
Burnettweldia corallina
Coral Gall Wasp
Burnettweldia corallina is a cynipid gall wasp that induces distinctive detachable galls on blue oaks (Quercus douglasii) in California. The species was formerly classified under the genera Disholcaspis and Holcaspis before its current placement in Burnettweldia. The wasp oviposits at the base of leaf petioles, and the resulting galls change color dramatically as they mature.
Burnettweldia plumbella
Beaked Twig Gall Wasp
Burnettweldia plumbella is a gall wasp that induces distinctive galls on oak trees. The species was transferred from the genus Disholcaspis to the newly erected genus Burnettweldia in 2021. It is commonly known as the beaked twig gall wasp due to the pointed tip of the galls it produces. The wasp has been documented on multiple oak species in western North America.
Burnettweldia washingtonensis
fuzzy gall wasp
Burnettweldia washingtonensis is a cynipid gall wasp that induces distinctive stem galls on white oaks (Quercus sect. Quercus) along the Pacific coast of North America. The species was originally described as Cynips washingtonensis in 1894 and later transferred to Disholcaspis before its current placement in Burnettweldia. It is locally common and among the more frequently observed oak gall wasps in its range, with over 1,400 citizen science records.