Late one afternoon in early September of 2005, I visited the Tanque Verde Wash near Wentworth Road here in Tucson, Arizona, and I observed hundreds of White-lined Sphinx (Hyles lineata) caterpillars there feeding on various species of Boerhavia and other plants in a dense field of weeds and grass at the center of the wash.
White-lined Sphinx caterpillars are quite variable in color, and it's likely that this smaller, lighter caterpillar below is also that of a White-lined Sphinx, but just a bit younger than the one above.
I enjoy watching White-lined Sphinx moths visiting the flowers in my garden just after sunset. Like hummingbirds, these large, plump moths dart nimbly about the garden and stop to hover in front of flowers as they sip nectar. They are especially fond of Japanese Honeysuckle (Lonicera japonica) with it's fragrant, white to pale yellow, tubular, sweet nectar-filled flowers.