Disholcaspis quercusmamma (agamic)

Callirhytis seminator (sexgen)

Euhexomyza schineri

Antistrophus silphii

Disholcaspis mamma

Rough Bullet Gall Gall Wasp (Disholcaspis mamma Cresson) Swamp White Oak (Quercus bicolor Willd.) These round, nipple-tipped galls are found on several species of oaks. They are colored green and red when young, velvety to touch, later becoming red or dark brown. In winter the galls are very hard and may be cut with difficulty. Rough Bullet Galls are generally found on young shoots of oak. 

Callirhytis seminator

Quercus alba

A showy and attractive gall growth on oak twigs. The large number of small, hairy galls are attached to a common point to form this pinkish-white, wooly growth. A gall with a similar appearance may be found on several other species of oak. The Wool Sower was called by E. P. Felt ". . . one of the finest of natural objects." 

[photograph included]

Agromyza schineri Giraud.

Quaking Aspen {Populus tremuloides Michx.) Although quaking aspen belongs with the Poplars, it is a more common tree in north central Illinois. The gall is a rather irregular, oval swelling on smaller twigs. The gray-green color of these twig galls resembles that of the twigs themselves. Note that the new, leafy shoots appear to grow itself. (KB)

This rather uncommon gall appears at the tip of a growing stem of Cup Plant. It is green and often irregular in shape. The gall growth strongly re- sembles an unopened flower bud. (KB)

Some plant galls of Illinois