Callirhytis quercuspunctata

Distinguished from other oak gall wasps by the distinctive gouty gall morphology: hard, woody, irregular swellings on branches rather than leaves or acorns. Differs from the related horned oak gall wasp (Callirhytis cornigera) by lacking the characteristic horn-like projections on mature galls. Separated from bullet gall formers (Disholcaspis spp.) by the irregular, tumor-like gall shape versus the smooth, bullet-shaped galls. Leaf-galling cynipids such as Neuroterus and Cynips species produce entirely different gall structures on oak foliage. Accurate species-level identification typically requires gall examination and host oak species confirmation.

Associated with oak-dominated habitats including deciduous forests, woodlands, urban and suburban areas with oak plantings, and riparian corridors where host oaks occur. The wasp requires living oak tissue for gall induction and development.

Eastern North America, with observations concentrated in the United States. Documented from the Midwest through the eastern seaboard, including Missouri and Maryland. Distribution corresponds with range of host oak species.

Activity patterns follow the typical cynipid bimodal life cycle with spring and summer generations. Exact timing varies by geographic location and host oak phenology. Gall formation on branches becomes visible as woody swellings during growing seasons.

• Quercus spp. - hostInduces galls on oak branches and twigs; specific oak species associations require verification

Exhibits heterogonic life cycle with alternating parthenogenetic (agamic) and sexual generations, a characteristic of many cynipid wasps. The agamic generation produces females asexually that develop within woody branch galls. Sexual generation involves male and female wasps emerging from typically smaller, often leaf-based galls, though specific gall locations for C. quercuspunctata generations are not fully documented. Larval development occurs entirely within gall chambers, with adults emerging through exit holes chewed through gall tissue.

Females inject eggs into oak tissue along with gall-inducing chemical secretions that manipulate plant development. Larvae remain sedentary within galls, feeding on nutritive tissue. Adults emerge by chewing through gall walls using mandibles.

Acts as a gall inducer that creates habitat structure for a community of associated organisms. Galls may harbor inquilines, parasitoids, and predators forming complex food webs. The wasp functions as a primary consumer of oak tissue, though individual galls have minimal impact on healthy trees. Heavy infestations can contribute to branch dieback.

Primarily of academic and ecological interest. Galls may cause aesthetic concern in ornamental oaks. Heavy infestations potentially contribute to oak decline in stressed trees, though C. quercuspunctata is not considered a major forest pest compared to some related species. Provides educational opportunities for studying plant-insect interactions and gall biology.

• Callirhytis cornigeraAlso induces woody branch galls on oaks, but produces distinctive horned galls with spiny projections versus the irregular tumor-like gouty galls of C. quercuspunctata
• Disholcaspis spp.Form bullet galls—smooth, spherical, detachable galls on branches—distinctly different from the irregular, attached, tumor-like gouty galls
• Andricus spp.Many species induce oak galls but typically on leaves or acorns rather than woody branch tissue; gall morphology differs substantially

• gall wasp
• cynipid
• oak gall
• gouty gall
• parthenogenesis
• heterogony

• BugGuide
• iNaturalist taxon
• NCBI Taxonomy
• ID Challenge #3 | Beetles In The Bush
• What’s that on an oak leaf? Animal? Plant? Fungus? Nah, gall insect – Galls wasps, Cynipidae — Bug of the Week