Callirhytis quercussuttoni

Galls induced by C. quercussuttoni appear as woody, irregular swellings on oak stems, often clustered and resembling knobby outgrowths. The galls are hard and persistent, distinguishing them from the spongy oak apples produced by some related species. Identification to species level requires examination of gall morphology on specific host oaks in the red oak group, combined with geographic location on the Pacific coast.

Associated with oak woodlands and forests dominated by red oak group species (section Lobatae), particularly in Mediterranean and coastal climates of western North America.

West coast of North America. Documented in California on Quercus agrifolia and Q. wislizeni.

• Quercus agrifolia - gall inductioncoast live oak
• Quercus wislizeni - gall inductioninterior live oak

Gall induction modifies host plant tissue, creating specialized habitat for the wasp's larval development. The hard, woody galls persist on host stems and may serve as microhabitat for other organisms.

• Callirhytis quercuspunctataAlso induces gouty stem galls on oaks, but occurs in eastern North America rather than the Pacific coast; host range and geographic distribution are primary distinguishing features.
• Callirhytis clavulaProduces galls on oaks, but gall morphology differs—C. clavula galls are not described as succulent or exhibiting latex exudate, unlike some other cynipid galls.

• gall wasp
• Cynipidae
• oak gall
• stem gall
• Pacific coast
• Quercus

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy
• ID Challenge #3 | Beetles In The Bush