Excerpts from Jim Conrad's
from the June 27, 2010 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO
Another species showing up for the first time now that the rainy season is underway is shown above.
Volunteer butterfly identifier Bea in Ontario figures that that's a Giant White, GANYRA JOSEPHINA, a member of the large Family holding butterflies known as whites and sulfurs, the Pieridae. You've seen whites and sulfurs flitting around pools of water and cabbage patches. Generally they're smallish butterflies but the wingspan of this species is about 3-½ inches (9 cm), so it's a "giant," relatively speaking.
The Giant White specializes in open, dry, tropical and subtropical forests such as our scrubby-tending forests in the northern Yucatan. It occurs from southern Texas through Mexico and Central America, rarely straying north as far as Kansas and New Mexico. The caterpillars' food is listed as trees in the Caper Family, the Caparidaceae, which aren't conspicuous in this area, but ought to be present.