by Skip Via
skip@westvalleynaturalists.org

White-lined sphinx moths (Hyles lineata) are one of over a thousand varieties of sphinx moths, most of which occur in tropical zones. This one is common throughout most of Central America and North America to southern Canada. Hyles lineata is a type of hawk moth, but they are often called hummingbird moths because they resemble hummingbirds in appearance, size, and actions. They are generally common here in the valley, although their population numbers and locations vary from year to year.

Like most sphinx moths, the white-lined sphinx is mainly nocturnal, although some may be visible during the day. They commonly appear around dusk to feed on the nectar of a variety of flowers, including lilacs, columbines, phlox, and petunias in addition to many of our local native plants. They can hover like hummingbirds as they extend their long proboscis to feed on flower nectar.

The white-lined sphinx’s caterpillar is a large (3-4 inches) and has many color morphs. All have a distinct horn at the rear (usually orange, sometimes yellow) and are often referred to as horn worms. The horn looks menacing but the caterpillars are harmless to humans. They are voracious eaters, consuming green leaves of a variety of plants.

White-lined sphinx moth adults are capable of being effective pollinators for certain species of plant. Here on the valley there are typically two generations of moths per season. Their adult life span is somewhere between 10 and 30 days.