Numbers
Between 7-13 spp. in our area
(1), 8-14 total
(2) (see remarks)
Identification
Key to species adapted from
(3)
1. Head and thorax pubescent, not shining; marginal cells of forewing very elongate; forming galls on leaves or leaf petioles ... 2
Head and thorax glabrous, marginal cells not elongate; forming galls on buds or twigs ... 3
2. Large species (>5mm), wings rhomboidal, forming galls on leaf petioles:
P. venusta
Smaller species (typically between 2-4mm), forming galls of various types on leaves ...
P. celtidismamma complex (includes
P. celtidismamma,
P. celtidisvesicula,
P. celtidisasterisca,
P. celtidisumbilicus, and
P. cohabitans. See remarks below)
3. Forewings uniformly brown, forming glabrous galls on axillary buds:
P. celtidisgemma
Forewings maculate ... 5
4. Branches of medial cell sinuate, forming galls beneath bark on twigs:
P. celtidisinteneris
Branches of medial cell not sinuate ... 6
5. Forewings finely mottled apically (galls are unknown): P. dubia
Forewings with large maculae, forming pubescent galls on axillary buds:
P. pallida
Range
Throughout North America, mostly eastern
(2)Remarks
Within the
Pachypsylla celtidismamma complex, adults are indistinguishable, yet the galls are distinct. Historically, most authors have treated all leaf-gallers other than the blister-galler as synonyms of a single species,
P. celtidismamma. However, allozyme frequency testing and electrophoretic analysis suggests that there may be up to seven cryptic leaf-galling species, including an inquiline species; further genetic testing may eventually reveal the extent of species boundaries within this group
(4)(5).