|Male P. s. sennae, Tobago|
|Female P. s. sennae, Tobago|
Three, see text
The cloudless sulphur or cloudless giant sulphur (Phoebis sennae) is a midsized butterfly in the family Pieridae found in the New World. There are several similar species such as the yellow angled-sulphur (Anteos maerula), which has angled wings, or other sulphurs, which are much smaller.
Their range is wide, from South America to southern Canada, in particular southwestern Ontario. They are most common from Argentina to southern Texas and Florida, but are often visitors outside this range becoming more rare further north.
The common habitats of this butterfly are open spaces, gardens, glades, seashores, and watercourses.
The breeding season is dependent on the climate of the area, from midsummer to fall in the cooler areas, to year-round where the climate is warmer.
The cloudless sulphur starts off as a pitcher-shaped white egg. Eventually it will turn to a pale orange. The egg stage lasts six days.
Once the egg hatches, a caterpillar emerges that is yellow to greenish, striped on sides, with black dots in rows across the back. The caterpillar will build a tent in a host plant where it hides in the day. The host plant may be partridge pea (Chamaecrista cinerea), sennas (Senna), clovers (Trifolium), or other legumes (Fabaceae). The caterpillar will usually grow to a length between 41–45 mm (1.6–1.8 in).
The caterpillar will form a chrysalis that is pointed at both ends and humped in the middle. The chrysalis will be either yellow or green with pink or green stripes. From the chrysalis comes a medium-sized butterfly (55–70 mm (2.2–2.8 in)) with fairly elongated but not angled wings.
The male butterfly is clear yellow above and yellow or mottled with reddish brown below and the female is lemon-yellow to golden or white on both surfaces, with varying amounts of black spotting along the margin and a black open square or star on the bottom forewing. Wingspan: 63–78 mm (2.5–3.1 in).
- P. s. amphitrite (Feisthamel, 1839) – Chile
- P. s. sennae or P. s. eubule – Jamaica, South Carolina, , Kansas, Virginia, Florida, Cuba
- P. s. marcellina (Cramer, ) – Mexico, Uruguay, Galapagos, Surinam, Honduras, Brazil, Argentina, Bolivia, Peru
- Cloudless Sulphur, Butterflies of Canada
- Lady Bird Johnson Wildflower Center Native Plant Information Network: ''Senna hebecarpa
- Clark, Dale. "Phoebis sennae". Dallas County Lepidopterists' Society. Retrieved 2008-07-21.
- Phoebis sennae, funet.fi