The wingspan of the Cloudless Sulphur (Phoebis sennae) ranges from 4.8 to 6.5 cm.
Adults are usually bright yellow, but some summer form females are pale yellow or white.
Females (on the photo) have a narrow black border on the wings and a dark spot in the middle of the front wing.
This is the subspecies Phoebis sennae marcellina which occurs in Texas, throughout Central America and south to Brazil.
Andrew Neild, author of The Butterflies of Venezuela and a recognized authority on Neotropical butterflies, helped me identifying this species.
Los Tarrales Natural Reserve, Patulul, Suchitepequez, Guatemala, 18 January 2020