Xystonyttus Kirkaldy, 1909

Cosmonyttus Stål, 1868: 103; Stål 1872: 83 (not Stål 1866: 295); Lethierry and Severin 1896: 178 [catalog; including erroneously Stål 1866: 295]. Type species: Zelus ichneumoneus Fabricius 1803: 286, by monotypy.

Xystonyttus Kirkaldy, 1909: 388 [as a new name for " Cosmonyttus, Stål, 1872 (not 1866)"]; Wygodzinsky 1949: 48 [catalog]; Putshkov and Putshkov 1985: 66 [catalog]; Maldonado 1990: 324 [catalog]; Maldonado and Lozada 1992: 165 [key]; Forero 2011: 16 [checklist]; Gil-Santana 2015: 37 [key], 2016: 92 [citations]; Gil-Santana et al. 2017: 41 [citation]. Type species: Zelus ichneumoneus Fabricius 1803: 286, by original designation.

Morphological remarks.

Head gibbous, large, as long as wide across eyes, densely covered with long setae on ventral and postocular portions; postantennal spines elongated, curved forward, apices acute. Legs: fore and hind femora curved at median portion; fore femora thickened, narrowing at apices; fore tibia curved at apical third; middle and hind legs elongated, slender. Hemelytra long, surpassing the abdomen by somewhat more than half of the length of the membrane.