Heteroecus sanctaeclarae

Identified by the distinctive mushroom-shaped or steeple-shaped bud galls it induces on host oaks. The galls are bilobed with a visible seam; the upper section resembles a rounded cap or dome, while the lower section forms the base. Gall coloration is variable, including beige, grey, pink, purple, and white. The larval chamber is positioned at the junction between the two gall sections. Adult wasps require specialist examination for species-level identification.

Associated with oak woodlands and chaparral containing huckleberry oak (Quercus vacciniifolia) and canyon live oak (Quercus chrysolepis).

Pacific coast of North America.

• Quercus vacciniifolia - induces gallshuckleberry oak
• Quercus chrysolepis - induces gallscanyon live oak

Develops within bud galls on host oaks. The larval chamber is located at the seam between the two sections of the bilobed gall.

Acts as a gall inducer, manipulating host oak tissue to form protective structures for larval development. The galls represent a form of plant-animal interaction that creates specialized microhabitats.

• Other Heteroecus speciesSame genus members also induce galls on oaks; species identification requires examination of gall morphology and adult wasp characteristics.
• Other Cynipidae on QuercusNumerous cynipid wasps induce galls on oaks; mushroom-shaped galls are distinctive to this species but may be confused with other bilobed gall forms without close inspection.

• gall wasp
• cynipid
• oak gall
• Pacific coast

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy