Gosse (1851) estimated (for the wet season) two months for the life cycle of Urania sloanus, between the April and June appearances of adults.
Unknown, the usual lifecycle of Urania takes about 30 days (Smith, 1983). During times of avocado flowering, adults of U. sloanus were around for about a fortnight (Gosse, 1851)
In this genus, large numbers of eggs can be produced by females soon after emergence (Gosse, 1851) as typical for a r-strategist.
The reproductive biology of the related U. fulgens has been covered in some detail by Smith (1992).
Like all other uraniines, tympanic organs in females are confined to the first abdominal segment, whilst they occur between the second and third abdominal segments and are larger in males (Lees and Smith, 1991). Hearing had not been studied in this species, but neurophysiology has been investigated in the Cuban endemic Urania boisduvalii (Coro, 1986)
Urania fulgens has sedentary and migratory phases although cues regulating this are insufficiently understood (Smith 1983).
In unstable or unpredictable environments, r-selection predominates as the ability to reproduce quickly is crucial. There is little advantage in adaptations that permit successful competition with other organisms, because the environment is likely to change again. Traits that are thought to be characteristic of r-selection include: high fecundity, small body size, early maturity onset, short generation time, and the ability to disperse offspring widely.