Royal Alberta Museum: Invertebrate Zoology - Bug Facts

[Caterpillars and Other Immature Insects]

Fact Sheets: Commonly Observed and Asked About Insects and Spiders Found in Alberta

White-lined Sphinx (Hyles lineata)

White-lined Sphinx
Credit: Terry Thormin

White-lined Sphinx caterpillar
Credit: Terry Thormin

INTRODUCTION

The White-lined Sphinx is not a permanent resident in Alberta, but rather a wanderer from farther south. It is also the only sphinx moth in Alberta that has a fall population of adults. At this time of year it is sometimes observed in the evening hovering at flowers much like a hummingbird would.

IDENTIFICATION

The adult moths can be up to 9 cm in wingspan. The front wings have a broad, pale tan stripe going from the base of the wing to the tip. Several thin white lines cross this broader stripe. The hind wings have a broad central pink stripe bordered on either side by black. The caterpillar, which can get up to about 6 cm long, is green with a series of black stripes down the length that are additionally striped and dotted with yellow and pink. The extent of the striping and spotting varies considerably from one individual to the next. Like most sphinx moth caterpillars, this species has a pointed horn near the back end.

DISTRIBUTION

Although distributed across most of North America from Mexico to central Canada, this species is most common in the west. In Alberta it does not survive the winters, but new individuals invade from the south most springs.

TIME OF YEAR

Moths tend to appear first in mid-May and will last through the month of June. Caterpillars may show up fairly early in July and last into mid-August. This species is unique amongst sphinx moths in Alberta in that it can have a second generation of adults in late August and September. The abundance of this species varies from year to year and some years there are no records of this species in the province.

HABITAT AND HABITS

This is a species of forest edges, weedy fields and even back yards. Adults feed at flowers in the evening, hovering just like hummingbirds. The caterpillars feed on leaves of apple trees, four-o'clocks and willow-herbs. Caterpillars are most likely to be seen when they are fully grown because at that time they come down to the ground and go looking for a place to pupate. They pupate in the soil usually about 2 to 10 cm below the surface.

SIMILAR SPECIES

The Galium Sphinx, Hyles gallii, looks rather similar as an adult, but averages smaller and lacks the fine white lines crossing the front wings.

COMMENTS

On occasion people bring in either the moth or caterpillar for identification. As a rule this is just sparked by curiosity at such a large impressive insect, but some people express concern over the caterpillar because of the horn at the back end. This is not a stinger and the caterpillar is not in any way dangerous. We also occasionally get phone calls in the fall from people who have seen "a cross between a moth and a hummingbird hovering at flowers in the evening". These are undoubtably sightings of this moth.

For information on how to over-winter pupae of this species, see How to over-winter butterfly and moth pupae

For more information on the White-lined Sphinx you can visit the University of Alberta’s entomology collection species page.

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Last update: December 10 2004