The Marcellina Sulphur (Phoebis marcellina) is a large, vibrant butterfly known for its brilliant yellow colour and strong, fast flight. Males are primarily brilliant, clear yellow on the upper side with virtually no markings. Females can range from yellow to nearly white. They often feature black or brown markings along the wing margins and a distinctive dark spot on the forewing. They thrive in open, sunny areas such as gardens, parks, forest edges, and roadsides.