Distribution Mexico-Central America and southeastern Brazil.
Systematics Never revised. Species listing here follows Mielke & Grehan (2012) and excluded six Phassus species proposed in the literature (see Nielsen et al., 2000), but lack sufficient similarity corresponding to the type species of Phassus. These were identified as incertae sedis by Mielke & Grehan (2012). The names eldorado and pretiosus were subsequently sysnoymised and transferred to Sthenopis (Mielke & Grehan, 2016). The remaining species may or may not prove to be monophyletic. The larval morphology of Phassus huebneri was described in detail by Grehan & Rawlins (2003).
Biology Larvae are stem borers of shrubs or small trees. In spite of all the popular attention to tropical forest ecology and biodiversity and that several of the Phassus genus are among the largest and often collected tropical forest ghost moths, the almost nothing is documented about their biology with the exception of work by Williams (1935) and Moreno (1988).
References Grehan, J. R. and J. E. Rawlins. 2003.Larval description of the New World ghost moth Phassus and the evolutionary biogeography of wood boring Hepialidae (Lepidoptera: Exoporia: Hepialoidea). Journal of the Washington Entomological Society 105: 733-755. Mielke, C.G.C. & J.R. Grehan 2012.Catalogue of the Latin American Hepialidae with taxonomic remarks (Lepidoptera). Nachricten des Entomologischen Veriens Apollo, N. F. 32: 131–158. Mielke, C.G.C. & J.R. Grehan, 2016. Description of a new species of Phassus Walker, 1856 from Costa Rica, Pallas, gen. n., with a new species from Guatemala, and taxonomic notes on Sthenopis Packard,  (Lepidoptera, Hepialdiae). The European Entomologist 7, 113-134. Moreno, G. 1989. Biología de las especies de Phassus y Aepytus (Lepidoptera: Hepialidae) en localidades de elevación media en Costa Rica. Tesis Lic. Heredia, CR, Universidad Nacional. 161 p.Excerpt1, Excerpt2, Excerpt3 Williams, F.X. 1935.Phassus pharus Druce. A moth borer attacking sugar cane in Guatemala. Hawaiian Planters’ Record 39, 292–297.
Phassus exclamationis Pfitzner, 1938 (no information) Phassus rosulentus Weymer, 1907 Mexico Jalapa Incertae Sedis
Phassus costaricensis Druce, 1887 (Not Phassus but Gymelloxes) Phassus guianensis Schaus, 1940 (Not Phassus, but member of tergal lobe clade) Phassus smithi (not Phassus, cibyrine clade) Druce, 1889 Mexico: Vera Cruz, Atoya Flight: May Holotype female: Natural History Museum, London
Phassus transversus Walker, 1856 Brazil: Rio Janeiro