In 1991 in eastern Venezuela, Frank Saager found specimens of what he was to call Psalmopoeus irminia , with regional locality comprising Estado Guyana and the Gran Sabana (Grand Savanna). More specific localities he documents within the Gran Sabana (inset, left):
Throughout the rolling plains that dominate the Gran Sabana are spectacular geological features, including sedimentary massifs (tepuis), sprawling cave systems, underground rivers, and sinkholes. All are the result of eons of water acting on calcium carbonate. One of the localities reported is the 7,671 ft. Roraima Tepui, or rather the vicinity thereof, as Saager states P. irminia is not found above 2,000 ft.
Within Estado Guyana and the Gran Sabana, P. irminia is reportedly widespread but not common. Saager found them on trees in areas of contiguous forest, rarer due to centuries of slash and burn he writes. The forests receive seasonal rainfall. According to Saager, day/night extremes of 104/59F (40/15C) are not uncommon. Specimens were found under bark or in holes associated with branches or roots. These observations comport with hobbyist experience.
Mating occurs in the dry season (December to June), with spiderlings emerging in 7-8 weeks (5-6 weeks for first instar), numbering 50-200 (100 typical) .
– view of Auyan Tepui with an Uruyen indigenous village and forested/deforested areas in the foreground
Saager’s account is rich compared to most scientific descriptions, with information helpful to keeper and breeder alike.
 Saager, F. (1994). Psalmopoeus irminia sp. n., Beschreibung einer neuen Aviculariinae (Theraphosidae, Aviculariinae, genus Psalmopoeus) inclusive einem Vergleich mit Psalmopoeus cambridgei. Arthropoda 2: 59-71.