Pachypsylla celtidis-pubescens n. sp.

This gall on the upper side of the leaf is represented by a small circular cup-shaped impression, surrounded by a rather wide, thickened, and elevated margin, and furnished at the bottom with a small, usually star- shaped, median nipple. The bottom and sides of the impression are smooth and shining, and occasionally beset with a few scattered hairs; the elevated margin is coarsely rugose-plicate, and usually also shining. Average diameter of gall, including elevated rim, about 3 mm; without the latter, nearly 2mm. On the under side of leaf it is usually semi- globular, entirely sessile, sometimes more flattened, rarely more globular and then less sessile. Surface more or less rugose, not shining, and covered with long but not densely placed white woolly hairs. There is sometimes a small apical nipple surrounded by a slight depression. Average diameter, 3 mm. Color pale greenish-yellow. The walls are very thin, but much thicker than the leaf itself; the roof is straight and the cell comparatively large and crescent-shaped in a cross- cut. Mode of issuing of mature pupa as in the preceding.

- CV Riley: (1890) Insects injurious to the hackberry^©

Reference: https://www.biodiversitylibrary.org/item/42358#page/634/mode/1up