Cynipid
Guides
Neuroterus tantulus
Neuroterus tantulus is a species of gall wasp in the family Cynipidae. Like other members of the genus Neuroterus, this species induces the formation of galls on oak leaves. The genus Neuroterus is known for producing small, often disc-shaped or pouch-like leaf galls on various oak species. Neuroterus tantulus has been documented through numerous observations, indicating it is relatively widespread where its oak hosts occur.
Neuroterus washingtonensis
Neuroterus washingtonensis is a North American cynipid gall wasp first described by Beutenmüller in 1913. It is known to induce galls on oak (Quercus) species and has been documented as a host for the introduced parasitoid wasp Bootanomyia dorsalis on the Pacific coast of North America. The species is part of the diverse Neuroterus genus, which includes gall-forming wasps known for complex life cycles often involving alternating generations on different oak tissues.
Odontocynips nebulosa
root gall wasp
Odontocynips nebulosa is a cynipid wasp that induces large, woody, subterranean galls on oak roots. Adults are small and rarely observed; the galls are the primary sign of its presence. The species was long misidentified due to confusion with a different gall-former on oak leaves. It has a two-year life cycle and is restricted to the southeastern and central United States.
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.
Periclistus
Periclistus is a genus of micro-hymenopteran gall wasps (Cynipidae) comprising at least 17 described species. These wasps are obligate inquilines that occupy galls induced by other cynipid genera on plants in the rose family (Rosaceae), particularly roses (Rosa). Unlike gall inducers, Periclistus species have lost the ability to initiate galls but retain the capacity to modify existing gall tissue, inducing nutritive tissue for their own larvae. The genus exhibits a phylogenetic divide between Palaearctic and Nearctic clades, with host specificity ranging from specialists to generalists across different species.
Phanacis taraxaci
dandelion gall wasp
Phanacis taraxaci is a gall-forming cynipid wasp that induces galls on the leaves of common dandelion (Taraxacum officinale). The galls function as physiological sinks, actively redirecting carbon and mineral nutrients from host plant tissues. This species has been documented in Europe, northern Asia, and North America.
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.
Philonix fulvicollis
Philonix fulvicollis is a gall wasp species in the family Cynipidae, first described by Fitch in 1859. It has an alternation of sexual and asexual generations, a phenomenon confirmed through molecular analysis of cytb and ITS2 sequences. The species is distributed across eastern and central North America, with records from the United States and Canada. Like other cynipid wasps, it induces gall formation on host plants, though specific host associations require further documentation.
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.
Sphaeroteras pulchripennis
Sphaeroteras pulchripennis is a species of gall wasp in the family Cynipidae. The species name 'pulchripennis' (Latin: 'beautiful wing') refers to its distinctive wing coloration. As with other members of Cynipidae, this species induces gall formation on host plants, though specific host associations remain incompletely documented. It is a relatively rarely observed species with limited published biological data.
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.
Synergus
inquiline oak gall wasps
Synergus is a genus of inquiline gall wasps in the tribe Synergini (Hymenoptera: Cynipidae). Most species develop within galls induced by other cynipid wasps on oaks (Quercus), though some inhabit galls on chestnuts (Castanea). The genus is distributed worldwide, with notable diversity in the New World and Eastern Palaearctic. One species, S. itoensis, has independently evolved the ability to induce its own galls inside oak acorns, representing a rare transition from inquilinism to gall induction. Species are morphologically grouped by fore wing radial cell structure and mesopleural sculpture.
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 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.
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.