Disholcaspis sp.

[Photo caption]
On Q margaretta. Also on Q stellata. Contained pupae Sept 15. Adults were cut out Nov 13. Living adults were in breeding cage on Mar 1. Galls are harder, occur in larger groups and have a rougher surface than the bullet gall on white oak Disholcaspis quercus-globulus of which it has been made a synonym in literature. Bassett described it from Q prinoides under the name of rugosa. The life history needs to be worked out.

[Cynips rugosa is listed as a synonym of Disholcaspis quercusglobulus]

Holcaspis rugosa

Cynips rugosa

Quercus prinoides

Round, somewhat roughened, woody galls on branch of dwarf chestnut oak, Quercus prinoides. Frequently several are so crowded as to lose the spherical shape. Green with red side when young, turning brown. Free larval cell surrounded by brown hard-spongy mass. Diameter about 10-12 mm. Insects emerge in the fall.

Cynips rugosa

Scrub oak
Twig galls
round, sessile galls 1/2 to 1/4 in diameter.

Cynips rugosa

Round, hard galls, sessile, on the branches of Quercus prinoides. Size from 1/2 to 1/4 of an inch in diameter. They are attached to the branch by a small point. The surface when green is smooth and often quite red on the side exposed to the sun. When fully ripe they have a shrunken and shrivelled surface and the color varies from an ashen hue to a dull brown. The free larval cell is surrounded by a yellowish brown cellular mass, too dense to be called spongy, which fills the entire gall. This species has been known to me for many years, but until lately I have considered it a variety of C. globulus Harris, but a careful study convinces me that it is a distinct species. C. globulus is only on the white oak and rarely more than one or two galls in a place, and has even when dry a smooth surface, while C. rugosa is often found in clusters of four or five and even more, so closely compressed that the galls are of an angular or cuneate form. The flies are all females and they mature and leave the galls late in the fall, at least I have never been able to find them in the galls in winter.