Recently we have had a large number of caterpillars (Hyles lineata) appearing at the Thousand Palms Oasis Preserve. These caterpillars are seen feeding on the brown-eyed primrose among other wildflowers and other vegetation, and when they are not feeding they can be found crawling on the desert floor in their search for food or for softer, less clay-like soil. This stage, the larva, will burrow into the soil to pupate and two to three weeks later emerge in the adult form, the white-lined sphynx moth. The adults feed on mainly the nectar of desert wildflowers while they pursue a partner with which to mate and produce eggs. As many as 1000 eggs are laid by the female on leaves of host plants.
The adult form of this insect is a key pollinator of the rare lemon lilly, Lilium parryi. The flying adult hovers and darts about quickly for which habits it is sometimes called the Hummingbird Moth. Wingspans range from two to eight inches. The adult usually flies at dawn and dusk and also at night time, but also occasionally during the day time.
The caterpillar is usually a bright yellow-green with black spots or stripes on the back, to almost entirely black with only glimpses of yellow breaking up the black. Each caterpillar has a posterior horn as decoration. This horn is flexible and sometimes brightly colored, but it is NOT a stinger.
The insect is found throughout all north American desert regions.