This species is related to the tomato hornworm. It is part of a large family of moths known as the Sphingidae, or hawk moths. The white-lined sphinx is a big moth that flies like a hummingbird, hovering in front of flowers to drink nectar through its long, flexible "tongue." The adult is sometimes called the "striped morning hawkmoth," because its flies at dusk and dawn. If you're outside and it's getting dark and a big moth swoops by the hover in front of some flowers, it's almost certainly a hawkmoth of some kind. The caterpillars come in several forms: some are green, some are brown, and some nearly black.