Genus Paralixes Caldwell, 1945

Genus Paralixes Caldwell, 1945: 107.

Note: This genus described as a subgenus of Ulixes, status revised by Gnezdilov & O’Brien 2006b: 224.

Type species (in original combination): Issus scutatus Walker, 1858a: 44.

(Type species of Ulixes (Ulixes) is Issus marmoreus Stål, 1861a: 150).




Southwestern US and Mesoamerica.


Distribution of Paralixes (as of 14 Jan. 2019)

Recognized species

There are five species currently assigned to this genus.

Paralixes fowleri (Melichar, 1906) – Mexico (Durango)
Hysteropterum fowleri Melichar 1906: 149, new name for unavailable H. montanum Fowler, 1904 (nec Becker 1865).
Hysteropterum montanum Fowler 1904: 120.
Paralixes fowleri (Melichar 1906); comb. by Gnezdilov & O’Brien 2008: 15.

Paralixes horizontalis (Caldwell 1945:108) – Mexico (Chiapas)
Ulixes (Paralixes) horizontalis Caldwell 1945.
Paralixes horizontalis (Caldwell 1945); status by implication Gnezdilov & O’Brien 2006: 224.

Paralixes intermedius (Fowler 1904: 115) – Mexico (Durango), Guatemala
Ulixes intermedius Fowler 1904.
Paralixes intermedius (Fowler 1904); status by implication Gnezdilov & O’Brien 2006: 224.

Paralixes perpendicularis (Caldwell 1945:108) – Mexico (Tamaulipas).
Ulixes (Paralixes) perpendicularis Caldwell 1945.
Paralixes perpendicularis (Caldwell 1945); status by implication Gnezdilov & O’Brien 2006: 224.

Paralixes scutatus (Walker, 1858a) – USA: AZ, TX; Mexico, Guatemala
Issus scutatus Walker, 1858a: 44.
Ulixes (Paralixes) scutatus (Walker, 1858); comb. by Caldwell 1945: 108.
Paralixes scutatus (Walker, 1858); status by Gnezdilov & O’Brien 2006: 224.


The species of Ulixes Stål. 1861c: 208 are as follows:

Economic Importance

Limited – species are rarely encountered.

Plant associations


Hosts from Wilson et al. 1994; plant names from USDA PLANTS or Tropicos.


The differences between Ulixes and Paralixes are as follows (according to Caldwell 1945: 107)

Ulixes – frons perpendicular and the clypeus strongly inflexed, elytra angled at the ‘shoulders’, Sc2 vein forming a sharp line from which the costal margin is perpendicular or inflexed, vein Cu1 definitely branched, hind wing well developed with strong venation, hind tibiae with 2 spines.

Ulixes marmoreus from Melichar 1906

Lateral view of head of Ulixes marmoreus from Melichar 1906

Paralixes – Face evenly curved in profile (the clypeus may be horizontal but the face is retreating or curved and there is no sudden break in the plane of the frons and clypeus), tegmina sloped to the shoulders and not strongly angled, costal margin not inflexed, hind wings not fully developed with veins not reaching apical margin, and hind tibia with 3-4 spines.

Hind wings absent or rudimentary, body rounded in dorsal view, wings strongly reticulate; mesonotum with lateral carinae not elevated (vs. Traxus; clypeus on same plane as frons (in lateral view; vs. TraxusUlixes)

This genus is rarely encountered.

Paralixes perpendicularis

Paralixes perpendicularis (paratype)

Paralixes scutatus

Paralixes scutatus (holotype)

Online resources

Bugguide. (not present, link to family)
FLOW. (some species incorrectly treated as Ulixes)
BOLD. (to subfamily, genus not present)
Discover Life.


Adults are evidently taken sweeping or beating. Specimens are uncommonly encountered and I have seen few in collections.

Molecular resources

There are no data for this genus (or Ulixes) on Genbank or Barcode of Life (as of 14 Jan 2019). Barcode of Life has a good listing of genera in Issidae.

Selected references
Bartlett, C. R., L. B. O’Brien and S. W. Wilson. 2014. A review of the planthoppers (Hemiptera: Fulgoroidea) of the United States. Memoirs of the American Entomological Society 50: 1-287.

Caldwell, J. S. 1945. Notes on Issidae from Mexico (Homoptera: Fulgoroidea). Annals of the Entomological Society of America 38: 89-120.

Doering. K. C. 1938. A contribution to the taxonomy of the subfamily Issinae in America north of Mexico (Fulgoroidea: Homoptera. Part II. University of Kansas Science Bulletin 25(20): 447-575.

Fowler, W. W. 1904. Order Rhynchota. Suborder Hemiptera-Homoptera. (Continued). Biologia Centrali-Americana 1: 77-124. (link to Isssidae, p. 113)

Gnezdilov, V. M. 2016. Notes on the phylogenetic relationships of planthoppers of the family Issidae (Hemiptera, Fulgoroidea) of the Western Palaearctic fauna, with descriptions of two new genera. Entomologicheskoe Obozrenie 95(2): 362-382.

Gnezdilov, V. M. and L. B. O’Brien. 2006. Generic changes in United States Issini (Hemiptera, Fulgoroidea, Issidae). Insecta Mundi 20(3-4): 217-225.

Gnezdilov, V. M. and L. B. O’Brien. 2008. New taxa and combinations in Neotropical Issidae (Hemiptera: Fulgoroidea). Insecta Mundi 31: 1-26.

Melichar, L. 1906a. Monographie der Issiden. (Homoptera). Abhandlungen der Kaiserlich-Königliche Zoologisch-Botanischen Gesellschaft in Wien 3: 1-327.

Metcalf, Z. P. 1958. General Catalogue of the Homoptera. Fascicle IV, Fulgoroidea, Part 15, Issidae. Waverly Press, Inc., Baltimore, Maryland.

O’Brien, L. B. 1988. Taxonomic changes in North American Issidae (Homoptera: Fulgoroidea). Annals of the Entomological Society of America 81(6): 865-869.

Spinola, M. 1839a. Essai sur les Fulgorelles, sous-tribu de la tribu des Cicadaires, ordre des Rhyngotes. Annales de la Société Entomologique de France 8: 133-337.

Spinola, M. 1839b. Essai sur les Fulgorelles, sous-tribu de la tribu des Cicadaires, ordre des Rhyngotes. (Suite). Annales de la Société Entomologique de France 8: 339-454.

Stål, C, 1861a. Miscellanea hemopterologica. Stettin Entomologische Zeitung 22: 129-153.

Stål, C. 1861b. Genera nonnulla nova Cicadinorum. Annales de la Société entomologique de France. (4) 1: 613-622.

Stål, C. 1861c. Nova methodus familias quasdam Hemipterorum dispondendi genera Issidarum synoptice disposita. Öfversigt af Kongliga Svenska Vetenskaps-Akademiens Förhandlingar 18: 195-212.

Stål, C. 1864a. Hemiptera mexicana enumeravit speciesque novas descripsit. (Continuatio). Stettin Entomologische Zeitung 25: 49-86.

Wang, M. L., Y. L. Zhang and T. Bourgoin. 2016. Planthopper family Issidae (Insecta: Hemiptera: Fulgoromorpha): Linking molecular phylogeny with classification. Molecular Phylogenetics and Evolution 105:224-234.

Walker, F. 1851. List of the specimens of Homopterous Insects in the collection of the British Museum. British Museum, London. 2: 261-636.

Walker, F. 1858a. Homoptera. Insecta Saundersiana: or characters of undescribed insects in the collection of William Wilson Saunders, Esq. British Museum, London. Pp. 1-117.

Wilson, S. W., C. Mitter, R. F. Denno and M. R. Wilson. 1994. Evolutionary patterns of host plant use by delphacid planthoppers and their relatives. In: R. F. Denno and T. J. Perfect, (eds.). Planthoppers: Their Ecology and Management. Chapman and Hall, New York. Pp. 7-45 & Appendix.

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