The gulf fritillary is a simply gorgeous butterfly, one of the most striking insects in North America. It has the orange and black upperside of most fritillary species, but underneath it is shaded with crimson, rich coffee-brown, and brightly metallic silver spots. Interestingly, it is not a true fritillary; it's a member of a tropical group of butterflies sometimes called longwings or Heliconiids. There are no other members of this group that resemble the gulf fritillary, and the group is well known for its mimicry of other species, so it's likely that the gulf fritillary is "copying" the colors of the true fritillaries in order to gain some protection from predators. Of course, it could also be the other way around, and idea supported by the fact that Heliconiid caterpillars feed on vines -- in this case, Passiflora vines -- that are known to have toxic sap.

Whatever the case, the spiny caterpillar of the gulf fritillary is sometimes found on passion flower vines, especially in Florida and Texas. It is a southern species, but is sometimes found as far north as the Great Lakes.