Oak-gall
Guides
Paracraspis patelloides
Bowl Gall Wasp
Paracraspis patelloides, commonly known as the Bowl Gall Wasp, is a species of cynipid wasp that induces distinctive gall formation on host plants. First described by Trotter in 1910 under the genus Andricus, it was later transferred to Paracraspis. The species is part of the diverse Cynipidae family, which contains numerous gall-inducing wasps primarily associated with oaks and related plants. Observations suggest it is moderately well-documented, with over 100 records on iNaturalist.
Philonix
oak gall wasps
Philonix is a genus of oak gall wasps in the family Cynipidae, restricted to North America (Canada, United States, and Mexico). Species in this genus induce spherical, soft, fleshy galls on white oaks (Quercus sect. Quercus), typically on the undersides of leaves. The genus was first described by Asa Fitch in 1859. Unlike many cynipid wasps, alternate sexual and asexual generations have not been documented in Philonix.
Phylloteras
Phylloteras is a North American genus of gall wasps in the family Cynipidae, tribe Cynipini. These insects are specialized associates of oak trees (Quercus), inducing galls on leaves. The genus contains at least 4 described species, with estimates suggesting up to 11 species may exist. As members of the oak gall wasp tribe, they exhibit the characteristic life history of alternating generations between sexual and asexual forms, often with distinct gall morphologies for each generation.
Phylloteras cupella
urn gall wasp, banded urn gall wasp
Phylloteras cupella is a cynipid wasp that induces distinctive leaf galls on multiple oak species in western North America. The wasp measures 1.3–2 mm in length. Its galls display a characteristic ombré color gradient, transitioning from lighter tones at the top to darker shades below, with new galls appearing yellow, red, or mauve, aging to purple, and ultimately turning brown. The species was originally described as Trigonaspis cupella by Weld in 1926 and later transferred to Phylloteras.
Phylloteras sigma
Phylloteras sigma is a species of gall wasp in the family Cynipidae. As a member of this family, it is an obligate gall-former on oak trees (Quercus species). The genus Phylloteras is associated with leaf galls on oaks, and species in this genus induce distinctive galls on oak foliage. Like other Cynipidae, P. sigma has a complex life cycle that typically alternates between sexual and asexual generations, though specific details for this species remain poorly documented.
Phylloteras volutellae
conical oak gall wasp
Phylloteras volutellae is a cynipid gall wasp native to North America that induces distinctive conical galls on the leaves of white oaks (Quercus section Quercus). The species is best known for the detachable, clustered galls formed on leaf undersides, each housing a single larva. Adults emerge in early January, though adult morphology remains undescribed.
Polystepha globosa
Polystepha globosa is a species of gall midge in the family Cecidomyiidae, a group of small flies known for inducing galls on plants. The species was described by Felt in 1909. Gall midges in this genus are associated with oak species (Quercus), where larvae develop within plant tissue and cause characteristic gall formations.
Protobalandricus spectabilis
Tapered Stem Gall Wasp
Protobalandricus spectabilis is a gall wasp species in the family Cynipidae, originally described as Andricus spectabilis by Kinsey in 1922 and later transferred to the genus Protobalandricus by Nicholls, Stone & Melika in 2018. It is commonly known as the Tapered Stem Gall Wasp. The species is part of the diverse Cynipini tribe, which includes numerous gall-inducing wasps associated with oaks and related plants. As a cynipid wasp, it induces the formation of plant galls during its life cycle, though specific gall morphology and host associations for this species require further documentation.
Striatoandricus
Striatoandricus is a genus of Neotropical gall wasps in the family Cynipidae, established by Pujade-Villar in 2020. The genus comprises approximately six described species, with four species transferred from the genus Andricus. Despite morphological similarities to Andricus, phylogenetic analyses indicate the two genera are not closely related. The genus name refers to the striations on the metasomal segments combined with its superficial resemblance to Andricus.
Striatoandricus aciculatus
Striatoandricus aciculatus is a species of gall wasp in the family Cynipidae, recently transferred from the genus Andricus to Striatoandricus based on phylogenetic and morphological studies. Like other members of its tribe, this species induces galls on oak trees (Quercus spp.) as part of its reproductive cycle. The species was originally described in 1909 and has been documented across multiple observations, indicating established populations in regions with suitable oak host availability.
Striatoandricus furnessulus
Striatoandricus furnessulus is a species of gall wasp in the family Cynipidae. It was originally described by Weld in 1944 and later transferred to the genus Striatoandricus in 2022. The species is known from Arizona, USA. As a member of the oak gall wasps, it likely induces galls on oak species (Quercus), though specific host associations have not been documented in available sources.
Synanthedon decipiens
oakgall clearwing, oak gall borer, Oak Gall Borer Moth
Synanthedon decipiens is a clearwing moth in the family Sesiidae, found in eastern North America. The species develops as a borer within woody oak galls formed by cynipid wasps. Adults are active primarily in June, with a possible second generation in September in some regions. The moth exhibits effective wasp mimicry, with a slender body, narrow transparent wings, and yellow abdominal banding.
Synanthedon sapygaeformis
Florida Oakgall Moth, Florida Oakgall Borer Moth
Synanthedon sapygaeformis is a clearwing moth in the family Sesiidae, commonly known as the Florida Oakgall Moth or Florida Oakgall Borer Moth. A subspecies, S. sapygaeformis floridensis, has been documented in Florida with biological notes published in 1964. As with other sesiids, this species exhibits wasp mimicry through its transparent wings and hymenopteran-like appearance. The specific epithet 'sapygaeformis' references a resemblance to wasps in the genus Sapyga.
Trigonaspis
Trigonaspis is a genus of cynipid wasps in the family Cynipidae, tribe Cynipini. These insects are gall wasps that induce galls on host plants. The genus was established by Hartig in 1840 and is part of the diverse radiation of oak gall wasps and related lineages.
Trigonaspis quercusforticorne
Trigonaspis quercusforticorne is a cynipid wasp that induces galls on oak trees. It is one of several oak gall wasps in the genus Trigonaspis, which are characterized by their distinctive gall formations on specific host tissues. The species has been documented across multiple European countries and is associated with Quercus species. Its biology and life history follow the typical pattern of unilocular cynipid galls with alternating sexual and asexual generations.
Trigonaspis radicola
Trigonaspis radicola is a species of gall wasp in the family Cynipidae. The species is known for inducing root galls on oak species (Quercus), distinguishing it from many cynipids that form galls on above-ground plant parts. Like other members of the tribe Cynipini, it has a complex life cycle involving alternating sexual and asexual generations, typically associated with different oak host species or plant structures. The species name 'radicola' (meaning 'root-dwelling') reflects its distinctive subterranean gall-forming habit.
Xanthoteras
Xanthoteras is a genus of gall-inducing wasps in the family Cynipidae, first described by William Harris Ashmead in 1897. The genus includes species that induce galls on oak trees (Quercus). The ball-tipped gall wasp, a notable member, was transferred to this genus from Trigonaspis. These wasps are part of the diverse community of cynipids that manipulate plant tissue to form protective structures for their developing larvae.
Xanthoteras eburneum
Xanthoteras eburneum is a species of gall wasp in the family Cynipidae. It is one of several North American species in the genus Xanthoteras, which induce distinctive galls on oak trees (Quercus spp.). The species is primarily known from observations of its characteristic galls rather than the adult wasps themselves.
Xanthoteras teres
Ball-tipped Gall Wasp
Xanthoteras teres is a cynipid gall wasp native to western North America. The species induces distinctive galls on oak leaves, characterized by an upright stalk topped with a fuzzy spherical structure. Formerly classified under the genus Trigonapsis, it was reclassified to Xanthoteras based on taxonomic revision. The wasp has been documented primarily in Oregon and California.
Zapatella
Zapatella is a genus of gall wasps in the family Cynipidae. The genus includes at least one well-documented species, Z. davisae, which has become a significant pest of black oak (Quercus velutina) in the northeastern United States. Gall wasps in this genus induce gall formation on oak hosts. The genus was described in 2012 by Pujade-Villar & Melika.
Zapatella quercusmedullae
Oak Rough Bulletgall Wasp
Zapatella quercusmedullae is a gall wasp in the family Cynipidae that induces galls on oak trees (Quercus). The species was transferred from Andricus to Zapatella based on phylogenetic studies. It produces distinctive bullet-shaped galls on twigs and branches of host oaks. The wasp has an alternating sexual and asexual generation life cycle typical of many Cynipini.
Zapatella quercusphellos
Zapatella quercusphellos is a species of gall wasp in the family Cynipidae. It is known to induce galls on oaks (Quercus species). The species was described by Carl Robert Osten Sacken and has been documented in the northeastern United States. It belongs to a genus of cynipid wasps specialized on oak hosts.
Zopheroteras compressum
Zopheroteras compressum is a species of gall wasp in the family Cynipidae, originally described as Acraspis compressus by Gillette in 1891. Like other members of its family, it is an obligate plant parasite that induces gall formation on host plants. The species has been documented through 202 iNaturalist observations, indicating it is not uncommon but remains poorly studied in the scientific literature. As a cynipid wasp, it likely exhibits the typical life history of alternating sexual and asexual generations, though specific details for this species are not well documented.
Zopheroteras sphaerula
Zopheroteras sphaerula is a species of gall wasp in the family Cynipidae, described by Weld in 1926. The genus Zopheroteras is part of the diverse cynipid radiation associated with oak galls. Like other members of its family, this species is presumed to be a specialist on oaks (Quercus), though specific host associations for this particular species require confirmation. The species has been documented through numerous iNaturalist observations, indicating it is not rare in suitable habitats.