Alternating-generations
Guides
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.
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 spinosa
Amphibolips spinosa is a cynipid wasp (family Cynipidae) first described by Ashmead in 1887. Like other members of its genus, this species likely induces galls on oak trees (Quercus spp.), though specific gall morphology and host associations remain incompletely documented. The species exhibits alternating sexual and asexual generations, a trait confirmed through molecular analysis of specimens from Florida and North Carolina. It is known from limited collection records in the southeastern United States.
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.
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 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.
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 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 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.
Diplolepis bicolor
spiny rose gall wasp, spiny bud gall wasp
Diplolepis bicolor is a cynipid gall wasp that induces bud galls on wild roses (Rosa spp.) across North America. The species produces distinctive spiny galls measuring 10–12 mm in diameter on rose buds. It exhibits the typical cynipid life cycle with alternating sexual and parthenogenetic generations. The galls superficially resemble those of Diplolepis polita but can be distinguished by their location on buds rather than leaves.
Druon quercuslanigerum
Druon quercuslanigerum is a cynipid gall wasp that alternates between sexual and asexual generations on live oaks. The sexual generation forms small galls on catkins in spring, while the asexual generation produces distinctive woolly galls on leaf undersides. It is one of only two species in the genus Druon with documented alternating generations.
Feron gigas
Saucer Gall Wasp
Feron gigas, the saucer gall wasp, is a cynipid wasp that induces distinct galls on oak leaves. It exhibits an alternating generation life cycle with morphologically different galls produced by all-female (agamic) and bisexual generations. The species is associated with several oak species in western North America and has been widely documented through citizen science observations.
Feron pattersonae
Plate Gall Wasp
Feron pattersonae, the plate gall wasp, is a cynipid wasp that induces distinct galls on white oaks, particularly blue oak (Quercus douglasii). The species exhibits cyclical parthenogenesis with two alternating generations per year: an all-female parthenogenetic generation and a bisexual generation. Each generation produces morphologically different galls—flat, circular, plate-like galls in summer, and pointed capsule galls on hair-like stems later in the year. The bisexual generation's galls were originally described as a separate species, Andricus pedicellatus, by Alfred Kinsey in 1922.
Melikaiella tumifica
Melikaiella tumifica is a cynipid gall wasp native to eastern North America. The species induces galls on oaks and exhibits a complex life cycle with alternating sexual and asexual generations. It has been introduced to Europe, where it was first documented in Germany on introduced red oak. Molecular studies have confirmed the connection between sexual and asexual generations through DNA sequencing.
Neuroterus quercusminutissimus
Neuroterus quercusminutissimus is a species of cynipid gall wasp in the genus Neuroterus. The species was described by Ashmead in 1885 and is associated with oak trees (Quercus species), as indicated by its specific epithet. Like other Neuroterus species, it induces the formation of galls on oak tissue. The genus Neuroterus contains approximately 50-60 species, many of which are known for their complex life cycles involving alternating generations that produce different gall types on oak leaves or other plant parts.
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.
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.