celtidismamma (Fletcher, 1883)

Type locality: USA, Iowa.

Additional distribution: USA, widely distributed in eastern and central North America; considered introduced in California.

Host plant: Celtis occidentalis, C. laevigata .

Remarks: First recorded in California in 1989 (Gill 1989); common name: hackberry nipple gall psyllid.

Parasitoids: Both Torymus sp, as a possible hyperparasitoid, and Eurytoma sp., have been reared from Pachypsylla sp.