Callaspidia Quercus-globulus, new species

Oak-bullet gall-flies

Smooth globular galls the size of a bullet, growing singly or two, three, or more in a cluster, upon white oak twigs, internally of a corky texture, each containing in its center a single worm lying in a oval whitish shell resembling a little egg 0.15 in length.

These bullet-like galls are most common and oftenest noticed of any of the galls on our oaks. When growing they are of a pale greenish color, shaded into bright red upon the side which is most exposed to the light, and with the fading of the leaves in autumn, they also fade to the same pale dull yellow hue with the dead leaves, even though the insect be still inclosed in them, to pass the winter, as it sometimes is.

- Asa Fitch: (1859) Fifth report on the noxious and other insects of the State of New York^©

Reference: https://www.biodiversitylibrary.org/item/239303#page/36/mode/1up