California Non-Oak Galls Acacia greggii (catclaw) Alnus sp. (alder) Arctostaphylos sp. (manzanita) Artemisia tridentata (sagebrush) Contarinia sp. Catclaw Leaflet Gall Midge Phytoptus laevis Alder Bead Gall Mite Tamalia coweni Manzanita Leaf Gall Aphid Rhopalomyia pomum Sponge Gall Midge Atriplex sp. (saltbush) Asphondylia floccosa Woolly Stem Gall Midge Asphondylia sp. Pom-Pom Bud Gall Midge Baccharis pilularis (coyote brush) Gnorimoschema baccharisella Baccharis Stem Gall Moth Puccinia evadens Baccharis Rust Gall Fungus Rhopalomyia baccharis Coyote Brush Stem Gall Midge Rhopalomyia californica Coyote Brush Bud Gall Midge Ceanothus sp. (ceanothus) Asphondylia ceanothi Ceanothus Bud Gall Midge Asphondylia sp. Vein Gall Midge Chrysolepis chrysophylla (giant chinquapin) and Chrysolepis sempervirens (bush chinquapin) Dryocosmus castanopsidis Chinquapin Flower Gall Wasp Dryocosmus juliae Ericameria sp. (rabbitbrush) Garrya sp. (silk tassel) Rhopalomyia utahensis Cotton Gall Midge Rhopalomyia sp. Spiny Cone Gall Midge Asphondylia garryae Silk Tassel Gall Midge Juniperus californica (California juniper) Walshomyia juniperina Juniper Urn Gall Midge Walshomyia sp. Juniper Gall Midge Larrea tridentata (creosote bush) Asphondylia apicata Creosote Bush Gall Midge Asphondylia auripila Creosote Stem Gall Midge Asphondylia digitata Creosote Antler Gall Midge Asphondylia discalis Creosote Bush Paddle Gall Midge Asphondylia fabalis Creosote Bush Gall Midge Asphondylia florea Creosote Bush Flower Gall Midge Asphondylia foliosa Leafy Bud Gall Midge Asphondylia pila Leaf Club Gall Midge Asphondylia resinosa Creosote Resin Gall Midge Asphondylia rosetta Creosote Cone Gall Midge Contarinia sp. Clasping Leaf Gall Midge Populus sp. (poplars; cottonwoods) Pemphigus populivenae Cottonwood Leaf Gall Aphid Pemphigus spyrothecae Rosa sp. (roses) Diplolepis californica Leafy Bract Gall Wasp Diplolepis nebulosa Diplolepis polita Spiny Leaf Gall Wasp Diplolepis rosae Pincushion Gall Wasp Diplolepis rosaefolii Rose Blister Gall Wasp Salix sp. (willows) Iteomyia sp. Willow Tooth Gall Midge Iteomyia sp. Willow Tube Gall Midge Pontania sp. Willow Gall Sawfly Rabdophaga rigidae Willow Beaked-gall Midge Rabdophaga salicisbrassicoides Willow Rosette Gall Midge Salvia mellifera (sage) Rhopalomyia audibertiae Sage Leaf Gall Midge

For more information about California galls, see Ron Russo's Plant Galls of the Western United States (2021), an update to and expansion of Ron's 2006 Field Guide to Plant Galls of California and Other Western States.