How to identify a White-lined Sphinx
This is one of the most recognizable hawk moths in North America. The forewings are olive-brown with a broad tan stripe running tip to base and bright white lines along the veins; the hindwings flash a band of rose-pink that shows in flight. The body is streaked with white. Wingspan is roughly 2.5 to 3.5 inches. It has a stout, torpedo-shaped body and powerful, blurring wingbeats, and it hovers at flowers with its long tongue extended, often mistaken for a small hummingbird. There are no tails or eyespots.
Where it lives
The White-lined Sphinx is one of the most widespread moths on the continent, common across the western United States and found nearly everywhere. Open records place it most often in California, Texas, Arizona, New Mexico, and Nevada, and it thrives in deserts, gardens, fields, and open country. In big population years its caterpillars can appear in huge numbers. See the wider list for California or Texas.
When it flies
Unlike the strictly summer silk moths, this species has a long, two-part season: a spring flight peaking March through May and a late-summer flight in August and September. It is active at dusk and into the night, and also flies on warm days. That spread makes it one of the moths you can find across much of the year in the south and west.
Caterpillars, host plants, and life cycle
The caterpillar is a large hornworm, variable from green to black with yellow or orange markings and a tail horn. It feeds on a remarkable range of plants - evening primrose, purslane, willow weed, grape, four o'clocks, and many garden and desert plants - which is part of why the species is so successful. When mature it burrows into the soil to pupate. There are typically two or more generations per year, and the pupa overwinters underground before the next spring flight.
How to see one at night
You have two good options. At dusk, watch nectar flowers - the moths hover and feed actively in the fading light and are easy to approach. After dark, a UV or mercury-vapor light on a white sheet draws them in, since moths respond most to short-wavelength light and artificial light disrupts the flight orientation they normally hold against the moon, leaving them circling the sheet. Warm, calm evenings in spring or late summer are ideal - see our good night for moths guide. To check whether it is active near you tonight, run the predictor, and for another hovering sphinx compare the Snowberry Clearwing.