Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

Interested in a 2022 BugGuide gathering in New Mexico?

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

National Moth Week 2020 photos of insects and people.

Photos of insects and people from the 2019 gathering in Louisiana, July 25-27

Discussion, insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Previous events


celtidismamma complex

Many galls - Pachypsylla celtidismamma Psyllid? under bark - Pachypsylla celtidisvesicula hopper in snow - Pachypsylla Pachypsylla? - Pachypsylla Hackberry Blister Gall Psyllid? - Pachypsylla celtidisvesicula Hackberry Blister Gall Psyllid? - Pachypsylla celtidisvesicula Male, Hackberry Blister Gall Psyllid? - Pachypsylla celtidisvesicula Galls? on hackberry - Pachypsylla celtidisasterisca
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Hemiptera (True Bugs, Cicadas, Hoppers, Aphids and Allies)
Suborder Sternorrhyncha (Plant-parasitic Hemipterans)
Superfamily Psylloidea
Family Aphalaridae
Subfamily Pachypsyllinae
Genus Pachypsylla (Hackberry Psyllids)
No Taxon celtidismamma complex
Other Common Names
Hackberry Leaf Gall Psyllids
In almost all instances, members of this group are best identified by the appearance of the gall, or from adults reared from galls. There is no reliable way to distinguish adults of most species.

Adults of the Hackberry Blister Gall Psyllid Pachypsylla celtidisvesicula have historically been distinguished from Pachypsylla celtidismamma sensu lato on the basis of their small size, the former being less than 2.5mm and the latter being over 3mm, with an ambiguous area in between. However, a series of psyllids reared from blister galls by Michael Palmer in Oklahoma measured 3.2mm, weakening the idea that size is a reliable way to distinguish between species in all but the smallest of hackberry psyllids. To further complicate the situation, adults of the star galler are also said to be measure under 3mm(1).

Adult females of the inquiline species Pachypsylla cohabitans may be distinguished by their green abdomen, whereas the abdomen is brown in the other members of this complex. P. cohabitans does not create galls itself; rather, it becomes incorporated in side cells of the galls of other leaf-galling Pachypsylla(1).

Overview of gall types
Images depict the gall as it appears on the ventral surface of the leaf.

Blister galls (P. celtidisvesicula)

Star galls (P. celtidisasterisca)

Disc galls (P. celtidisumbilicus)

Hairy nipple galls (P. celtidismamma [syn: P. celtidispubescens])

Glabrous nipple galls (P. celtidismamma [syn: P. celtidiscucurbita & P. celtidisglobula])
Throughout North America but most common east of the Rockies (2)
Hackberry (Ulmaceae: Celtis spp.) including C. occidentalis, C. reticulata, C. tenuifolia, & C. laevigata (3)
The Pachypsylla celtidismamma complex refers to all of the leaf-galling members of the genus Pachypsylla. With our current knowledge, adults belonging to this complex are indistinguishable from each other, though the galls themselves 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.

BugGuide currently recognizes the star-gall maker (P. celtidisasterisca) and disc-gall maker (P. celtidisumbilicus) as distinct species. The hairy nipplegall maker (P. celtidismamma & P. celtidispubescens) and glabrous nipplegall maker (P. celtidiscucurbita & P. celtidisglobula) are treated here as a single species, P. celtidismamma, but they may represent one or two distinct species(3). Further genetic testing may eventually reveal the extent of species boundaries within this group(3)(4).
Works Cited
1.First incidence of inquilinism in gall-forming psyllids, with a description of the new inquiline species
Yang, M.-M., C. Mitter & D.R. Miller. 2001. Zoologica Scripta, 30, 97–113.
2.Garden Insects of North America : The Ultimate Guide to Backyard Bugs (Princeton Field Guides)
Whitney Cranshaw. 2004. Princeton University Press.
3.Biosystematics of hackberry psyllids (Pachypsylla) and the evolution of gall and lerp formation in psyllids
Yang, M.-M. & C. Mitter. 1993. The Ecology and Evolution of Gall-forming Insects. United States Dept. of Agriculture.
4.The Authority and Types for the Hackberry Gall Psyllid Genus Pachypsylla (Riley) (Hemiptera: Psyllidae)
Thomas, D.B. 2011. Entomological News, 122(3):279-287.