In the Carribbean, these conspicuous large butterflies can be seen nectaring on Bougainvilea, Hibiscus and Lantana as well as many other tropical flowers.
The wings of males are sulphur yellow, while females are more of a lemon yellow. the wingspan ranges from 6.3 to 7.8cm, with females slightly larger than males, as is very common with butterflies.
Breeding throughout most of South America and the southern half of the USA, with some adults migrating through the northern states of the USA and into Canada, this lovely butterfly also occurs the West Indies including Barbados, where this photograph was taken in late April.
The larval foodplants are Cassia (senna) species in the family Fabaceae, from which the specific epithet is derived.
In the tropical climate of the Carribbean these butterflies breed all through the year, whereas in more temperate northern or southern countries their emergence coincides with summer.