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Species Pachypsylla celtidisumbilicus - Hackberry Disc Gall Psyllid

Galls on tree - Pachypsylla celtidisumbilicus Galls on tree - Pachypsylla celtidisumbilicus Galls on tree - Pachypsylla celtidisumbilicus Galls on tree - Pachypsylla celtidisumbilicus Galls on tree - Pachypsylla celtidisumbilicus Disc gall - Pachypsylla celtidisumbilicus Disc gall - Pachypsylla celtidisumbilicus
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)
Species celtidisumbilicus (Hackberry Disc Gall Psyllid)
Synonyms and other taxonomic changes
Pachypsylla celtidis-umbilicus Riley, 1890.
Explanation of Names
Pachypsylla celtidisumbilicus Riley, 1890
Gall on upper surface of leaf circular and abruptly depressed at its outer margin, gradually rising to surface level, with an elongate nipple in the center; ventral surface of the leaf elevated, 2mm in height and 5mm wide, circular, gradually rising with a shall depression in the center(1)
The adults are said to resemble P. celtidismamma.
Eastern US (2)
Celtis occidentalis (2)
Riley described the gall of this and several other leaf-galling species but never formally described the adults, which Riley (1890) said so closely resembled P. celtidismamma that "they can only be distinguished with difficulty". These two facts caused subsequent authors to treat Riley's names as either nomina nuda or as synonyms of P. celtidismamma. However, as D.B. Thomas (2011) points out, names published prior to 1931 based on descriptions of galls are indeed valid under the ICZN, and recent studies by Yang and Mitter (1994)(2) concluded that P. celtidismamma was indeed a cryptic-species complex, though more work needs to be done in order to fully understand which of Riley's species are indeed valid(3).
See also comment here.
See Also
Adults of P. celtidismamma are said to be nearly indistinguishable, though the galls are distinctly different:
Works Cited
1.Insects Injurious to Forest and Shade Trees
Alpheus, S.P. 1891. Fifth Report of the United States Entomological Commission.
2.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.
3.The Authority and Types for the Hackberry Gall Psyllid Genus Pachypsylla (Riley) (Hemiptera: Psyllidae)
Thomas, D.B. 2011. Entomological News, 122(3):279-287.