Texas Woolly Oak Galls

In an effort to simplify the identification of woolly looking oak galls in Texas, I pulled this info from BugGuide. It's just a first draft, so comments and suggestions are very welcome!

Charley Eiseman advises that galls on Texas oaks are largely understudied. The data for the Texas observations on BugGuide is VERY limited. Keep in mind there are probably several/many unidentified species, too.

If you are interested in helping to document galls (any, not just woolly ones) for identification, I recommend the following:

Photograph the whole leaf, top and bottom.
Photograph the gall up close.
If possible, break open the gall and photograph what is inside.
Perhaps most importantly, note the host plant.

Galls are frequently specific to a genus (oaks, elms, hackberries, etc) and to where they occur on the plant (upper-/lowerside of leaf, leaf midrib, petiole, stem, etc.) They also may or may not have features that affect the opposite side of the leaf which can help in identification.

Gall-forming Insect	Hosts	Gall type	Gall description	Sources
*Andricus pattoni*	WHITE OAKS Post Oak (stellata) White Shin Oak (breviloba) Sand Post Oak (margarettae)	Leaf midrib, underside	Begins to develop in August. Galls similar to Andricus quercusflocci (which is not a TX species.) "Woolly, dirty white, of 2-10 seed-like bodies attached by one end on midrib on upper or lower side, in fall." Unconfirmed in TX	BugGuide BG See also
*Andricus quercuslanigera* "Wool-bearing Gall Wasp"	LIVE OAKS Southern Live Oak (virginiana) [Texas Live Oak (fusiformis)]	Leaf midrib, underside	"Hemispherical or irregular tufts 1/2 inch long of rather long, whitish or reddish wool covering, 2 to 6 irregular brown, seed-like kernels on under side of midrib, diameter 1/12 inch, on live oak, summer."	BugGuide
*Callirhytis furva* "Furry Oak Leaf Gall Wasp"	RED OAKS	Leaf, upperside	"Probably on all the red oaks" "Small cluster of globular galls, 3-4 mm, each covered with short, straight brown hairs, upper side, fall" "Galls drop from leaves in October; adults emerge in the second or third spring in late March." Unconfirmed in TX	BugGuide
*Callirhytis lanata* "Woolly Oak Gall"	RED OAKS	Leaf, underside	"Forms woolly, detachable galls on leaves of various species in the red oak group. The galls drop in October and adults may emerge in the second, third, or fourth spring."	BugGuide
*Callirhytis quercusoperator* "Woolly Catkin Gall Wasp"	RED OAKS	Flower	"Oval masses 2 to 3 inches in diameter, hairs greenish white or rose tinted, sometimes deep red, there may be 150 or more cells each less than 1/10 of an inch in diameter."	BugGuide
*Callirhytis seminator* "Wool Sower Gall Wasp"	WHITE OAKS Post Oak (stellata)	Stem	"Spring; White with pink spots, detachable stem gall. Many celled. Around 20mm in diameter."	BugGuide
*Neuroterus quercusverrucarum* "Oak Flake Gall Wasp"	WHITE OAKS Bur Oak (macrocarpa) Chinkapin (muehlenbergii) Post Oak (stellata)	Leaf, underside	"Causes fuzzy, white to brown galls, about 2.5 mm across, on the undersides of leaves of oaks in the white oak group. Adults emerge from galls in April." Typically many scattered on one leaf.	BugGuide