Polyphemus moth vs Promethea moth

These two are easy to mix up. Here's how to tell a Polyphemus moth from a Promethea moth, and whether either one bites or stings.

≠The key differences

Polyphemus is larger with a prominent eyespot on the hindwing; Promethea lacks large eyespots.

	Polyphemus moth	Promethea moth
To humans	Non-toxic	Non-toxic
Size	11-15 cm wingspan	7.5-9.5 cm wingspan
Colours	Reddish brown, Tan, Olive-brown, Sky blue (eyespot center)	Reddish brown, Dark brown, Cream/white, Black
Family	Saturniidae	Saturniidae
Habitat	Deciduous woodlands, suburban yards, parks and areas with host trees	Deciduous forests, forest edges, riparian corridors and suburban areas with host trees
Range	Widespread across much of the United States and southern Canada, extending into Mexico	Eastern North America: from southern Canada through the eastern United States
Active	Spring and early summer (one or two broods depending on latitude); adults are nocturnal	Late spring to midsummer; one generation in the north, one or two generations farther south; adults fly at dusk and night, males often active during the day
Pest?	No	No

Very large wingspan (11-15 cm) with broad, rounded wings
Distinctive large circular eyespot on each hindwing with a clear center ringed with yellow, blue and black
Overall reddish-brown to tan coloration with wavy crosslines across wings
Males with notably feathered antennae; females with thinner antennae

Sexual dimorphism: females are reddish-pink with broad pale bands; males are darker brown and smaller.
Wingspan 7.5-9.5 cm with rounded hindwings typical of silk moths.
Small translucent or pale cell spot on each forewing.
Found on or near host trees (spicebush, sassafras, wild cherry, tulip tree, sweetgum).

Polyphemus is larger with a prominent eyespot on the hindwing; Promethea lacks large eyespots.

Polyphemus moth: Non-toxic. Promethea moth: Non-toxic. Polyphemus moths do not bite or sting. Adults do not bite or sting and are harmless.

Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.