Earlier this summer Erika and I saw an adult White-lined Sphynx in Erika's garden. Typical for the species, the moth fed just at dusk and fled by the time I found my camera. The adults are sometimes mistaken for hummingbirds and are often named "hummingbird moths."
On 3 September 2011, while performing our civic duty by weeding the mulch of a local playground, we dug up two White-lined Sphynx caterpillars, often known as hornworms. Unlike the similar Tomato Hornworm, this caterpillar usually does not damage gardens. The caterpillars feed on a wide range of host plants before digging into loose soil to go into chrysalis. Pupation occurs in a small, packed-earth chamber. Two to three weeks later they emerge as adult hummingbird moths (Colorado State University Extension Service).