Can You Identify This Caterpillar?

Ria, a forum member who teaches preschool in the Philippines, posted photos of some caterpillars she is raising. She found them in her schoolyard. We haven't confirmed the identity of these critters yet. Does anyone know what species these might be?

Here's what we know. The caterpillars feed on leaves of the frangipani tree, also known as calachuchi in the Philippines or by the scientific genus Plumeria. They're pretty big caterpillars, reaching about 3 inches in length. From the body shape of the caterpillars, they look like some kind of sphinx moth caterpillars. Ria reports that they seem to change from lighter to darker, or vice versa. It's not entirely clear whether they are changing color after each molt, or are perhaps readying themselves for pupation (some caterpillars change colors before pupating). Some of the caterpillars have already pupated, burrowing in the soil before they do.

Do you know what these caterpillars are called? Check out all of Ria's photos, and join our discussion in the forum.