Excerpts from Jim Conrad's
Naturalist Newsletter

Orange-barred Sulphur, PHOEBIS PHILEA

from the October 10, 2010 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO; limestone bedrock, elevation ~39m (~128ft), ~N20.676°, ~W88.569°
SULPHUR ON THE HIGHWAY

On the peaceful little blacktop road running south of Pisté, from the bike I spotted a yellow butterfly lying at the road's edge. He'd been hit by a car, leaving his wings cramped unnaturally below him. I knelt and gently spread the wings atop the road surface. You can see the pretty orange markings there above.

Bea in Ontario tells me that this is an Orange-barred Sulphur, PHOEBIS PHILEA, a member of the big Whites & Sulphurs Family of butterflies, the Pieridae. It's a common species, frequent along weedy roadsides, and I've seen it a lot. I hadn't photographed one until now because they're swift, high fliers. When it's hot and sunny this one just streaks about, not waiting for a digital camera to do all its grinding and configuring.

Orange-barred Sulphur, PHOEBIS PHILEA

Several look-alike yellow butterfly species are common here. You might find it interesting to compare a side shot of this week's Orange-barred Sulphur, shown above, with a similar side shot of an earlier-seen Dina Yellow, at www.backyardnature.net/yucatan/mariposa/butt061.jpg.

If you place those two images in different windows, side by side on the computer screen, it's fascinating to see how for the most part they're identical, but here and there there's a spot on one but not the other, or a wing vein that's shorter or more bent than on the other.

One reason Orange-barred Sulphurs are so common is that there's plenty here for them to eat. Their caterpillars feed on the genus Cassia in the Bean Family, and Cassias are common here. Adults take nectar from many different kinds of flowers. Thus you find them in all kinds of lowland, weedy sites, including gardens, parks, forest edges and, as I did, along roads.

The species is distributed from Brazil all through Latin America to the US border and southern Florida, plus it wanders irregularly as far north as Minnesota and Connecticut. This seems to be a species poised to take advantage of global warming.