Pachypsylla celtidisumbilicus

Celtis occidentalis

Galls disc-like or button-like, much flattened; upper depression with an outer rim and the central portion slightly raised with a median spine; under side wart-like, with a depression at middle

MD, VA, AR, MO, IA, MS

Pachypsylla celtidisumbilicus n. sp.

This gall occurs on the upper side of the leaf, is regularly circular in outline and abruptly depressed at its outer margin beneath the surface of the leaf. From this outer margin toward the center the gall gradually rises again to about the level of the surface or even above it, the center being furnished with an elongate nipple (frequently broken off). The color in fresh specimens is a little lighter than that of the leaf, but fully developed and dried specimens are more yellow. Surface opaque, either without any decided sculpture, or rugose and with the venation of the leaf still preserved. On the under side of the leaf it is distinctly elevated, averaging 2 mm in height and 5 mm wide, circular in outline, the sides not abruptly elevated but gradually rising, with a larger or smaller shallow depression at top which is often furnished with a small central nipple. Color, yellowish-green in fresh, and more yellow in dried specimens ; surface opaque, rugose. Gall woody and hard, the wall at the bottom about 1 mm in thickness; that of the roof about 0.5 mm. Cell formed as in the preceding species [Pachypsylla celtidisvesicula], but much larger; mode of issuing of mature pupa also as in the preceding. There is no difficulty in recognizing this gall, especially from its appearance on the upper side of a leaf.

Pachypsylla umbilicus

Circular, depressed leaf gall on the upper surface, the outer rim depressed, the central part slightly raised and with a median spine; wartlike on the under surface, much flattened and with a depression in the middle; height 2 mm, diameter 5 mm.

Pachypsylla celtidisumbilicus Riley, 1890

Pachypsylla celtidis-umbilicus Riley, 1890. USDA Bull. 7:619.
Pachypsylla celtidisumbilicus: Yang et al., 2001. Zoologica Scripta 30:111.