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How to identify it
- The adult is a heavy-bodied moth with a wingspan of 2 1/2 to 3 1/2 inches and a furry brown body crossed by six white stripes.[2][3]
- Each long, narrow, dark olive brown forewing has a tan band from base to tip, crossed by thin white lines along the veins. The black hindwings are bright reddish pink in the middle.[2][3]
- It hovers at deep, tubular flowers like a hummingbird while sipping nectar through a long tongue.[1][2][3]
- Caterpillars are hornworms with a pointed horn at the rear, which may be yellow, orange, yellowish green or black. Midwestern caterpillars are usually green with black stripes and yellow, orange or pink dots; western ones are often dull yellow or cream, and dark forms run to brown or nearly black.[2][3]
- University of Arizona researchers found the green and yellow caterpillar forms occur together in wild populations and are inherited, mainly through a single gene.[4]
- Full-grown caterpillars reach about 3 1/2 inches.[2]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Tomato and tobacco hornworms | Their adults fly after dusk and are rarely seen, and their caterpillars feed on tomatoes and related plants.[1] |
| Hummingbirds | At dusk the moth is easily taken for a hummingbird as it hovers at flowers. Look for antennae, the striped body and white-lined wings.[2][3][1] |
Where it lives
Occurs through most of North America, from southern Canada to Central America, and statewide in Missouri. It is the most common hornworm in Colorado. In Wisconsin it cannot survive the winter and flies up from the south most springs.[2][3][1]
Biology and life cycle
Larvae feed on a very wide range of plants, commonly purslane (portulaca), primrose and wild grape, and also apple, four o'clock, fuchsia, gaura, pentas, peony, tomato and willow-weed. Missouri calls purslane probably the favorite there.[1][2][3]
Adults take nectar from many flowers, including columbine, honeysuckle, lilac, jimsonweed, petunia, phlox and penstemon. Wisconsin notes they favor bright flowers by day and white or pale flowers in the evening.[2][3]
Females can each lay hundreds of eggs. Caterpillars go through five instars, then burrow 1 to 4 inches into loose soil and pupate in a chamber of packed earth.[2][1]
Wisconsin Extension says there are normally at least two generations a year, more in warm climates. In Wisconsin moths first appear in mid-May with a second flight in late August to September; in Missouri adults fly from early April into November.[2][3]
In a University of Arizona field study, female moths carried pollen from more kinds of flowers than males, a sign that the sexes visit different flowers.[5]
In a Texas study using clay models, birds made most attacks on both moths and caterpillars, and adult moth models were attacked about twice as often as caterpillar models.[6]
Damage and signs
- Larvae seldom significantly damage economically important plants; rare outbreaks can send caterpillars across roads when food runs out.[1]
- Wisconsin Extension describes caterpillars occasionally appearing in huge numbers and moving in hordes, eating entire plants; such outbreaks are especially common in the dry West.[2]
Health risk
The horn at the rear is not a stinger, and the caterpillar is harmless to people.[2]
Control
Prevention
Usually none is needed: the caterpillars seldom significantly damage economically important plants, and the adult moths pollinate flowers.[1][3]
Traps and physical control
Hornworms can be hand-picked, most easily near dusk and dawn when they feed on the outside of plants.[1]
Where sources disagree
When adults fly: Colorado State says the moth is usually most active in late afternoon and at dusk, Wisconsin Extension calls it mainly nocturnal but sometimes seen by day, and Missouri says adults often fly in daylight as well as at night.[1][2][3]
Winter: Wisconsin Extension says it cannot survive Wisconsin winters and arrives from the south, while Missouri lists it as a resident species found statewide.[2][3]
Common questions
- Is that a hummingbird or a moth at my flowers at dusk?
- It may be a whitelined sphinx, the moth most often seen hovering like a hummingbird.[1]
- Do whitelined sphinx caterpillars hurt gardens?
- They seldom significantly damage economically important plants.[1]
- Can the horn on the caterpillar sting?
- No. The horn is not a stinger, and the caterpillar is harmless to people.[2]
Sources
- Colorado State University Extension, “Hornworms and 'Hummingbird Moths' (Fact Sheet 5.517).” extension.colostate.edu/resource/hornworms-and-hummingbird-moths/ (accessed 2026-11-11)
- University of Wisconsin-Madison Extension, “White-lined Sphinx Moth, Hyles lineata – Wisconsin Horticulture.” hort.extension.wisc.edu/articles/white-lined-sphinx-moth-hyles-lineata/ (accessed 2026-11-11)
- Missouri Department of Conservation, “White-Lined Sphinx (Field Guide).” mdc.mo.gov/discover-nature/field-guide/white-lined-sphinx (accessed 2026-11-11)
- Journal of Insect Science, via PubMed, “Francois and Davidowitz (2020), Genetic color polymorphism of the whitelined sphinx moth larva (Lepidoptera: Sphingidae).” pubmed.ncbi.nlm.nih.gov/32809022/ (accessed 2026-11-11)
- Insect Science, via PubMed, “Smith, Davidowitz, Alarcon, Papaj and Bronstein (2022), Sex differences in the foraging behavior of a generalist hawkmoth.” pubmed.ncbi.nlm.nih.gov/33908191/ (accessed 2026-11-11)
- Insects, via PubMed, “Sanchez et al. (2025), The dangers of growing old: adult moths face higher predation pressures than caterpillars in Hyles lineata.” pubmed.ncbi.nlm.nih.gov/40332810/ (accessed 2026-11-11)
- iNaturalist, “Hyles lineata taxon page (order and family).” www.inaturalist.org/taxa/49348 (accessed 2026-10-06)