Burnettweldia plumbella (agamic)

Callirhytis congregata (sexgen)

Cynips q-kelloggii-acorn-cup-gall-wasp

Heteroecus pacificus (sexgen)

Walshomyia j-osteosperma-tube-gall-midge

Cembrotia coloradensis

Andricus quercuscalifornicus (agamic)

Walshomyia cupressi

Rhopalomyia baccharis

Tanaostigmodes howardii (integral stem)

[Stem gall, appearing either green or red overall with round yellow spots or bumps. Most examples of this species will have a distinctive long, curved beak, however, forms of this gall occurring on Quercus cornelius-mulleri (Muller's Oak) can have beaks that appear very small or indistinct.]

This cynipid wasp induces large, elongated, fleshy, polythalamous catkin galls, especially on coast live oaks.

Acorn Cup Gall Wasp

Oaks examined in mid-July on Mount Shasta in northern California were thoroughly affected by this gall insect. 

Host:
Quercus kelloggii

Heteroecus pacificus (bisexual generation)

Bisexual generation galls are conical, thorn-shaped, red-wine colored, monothalamous, and often in clusters. 

Hosts:
Quercus chrysolepis
Quercus vacciniifolia

Tube Gall Midge
*Walshomyia sp. C

This midge induces elongate, tubular, monothalamous galls on buds along the sides of scaly leaves of Utah juniper. 

Host:
Juniperus osteosperma

CYPRESS GALL MIDGE 
Walshomyia cupressi Pl. 40

This midge induces large, monothalamous, four-sided galls insummer on at least two cypress species in California. They appear as massive replicas of the terminal buds and often occur in clusters of three or four individual galls. 

Stem Gall Wasp
Tanaostigmodes howardii

This wasp has been associated with two different galls on catclaw. The first, an elliptical, sometimes lopsided, integral, monothalamous, stem gall on catclaw is a bit lopsided, measures up to 12mm long by5mm in diameter, and is the same color as the stems. 

Host:
Senegalia greggii

Field Guide to Plant Galls of California and Other Western States