Polyphemus Moth

The Polyphemus Moth is a large and widespread member of the giant silkmoth family Saturniidae, found across most of North America from southern Canada to Mexico. Its common name references the Cyclops Polyphemus of Greek mythology, inspired by the single prominent, eye-like transparent spot centered on each hindwing.

As with other giant silkmoths, the Polyphemus Moth has no functional mouthparts as an adult and does not feed, relying entirely on energy stored during its caterpillar stage to fuel a brief adult life focused solely on reproduction.

The species is remarkably adaptable, with caterpillars feeding on a wide range of deciduous tree species, allowing the moth to persist in habitats ranging from deep forest to suburban parks and gardens across a broad geographic range.

• Wings are tan to golden-brown or reddish-brown, with a large, translucent, blue-and-black-ringed eyespot centered on each hindwing.
• Forewings also show smaller eyespots and a fine pink or reddish line running near the outer wing margin.
• Body is stout and furry, colored to match the wings, with large, feathery (bipectinate) antennae in males used to detect pheromones.
• Large size, typically 4 to 6 inches across, ranks it among the largest moths in North America.
• The prominent, glassy hindwing eyespots (resembling a single large eye when flashed) distinguish it from similar-sized saturniids such as the Luna or Cecropia moth.

Widespread across nearly all of North America from southern Canada through the continental United States into Mexico, the Polyphemus Moth occupies deciduous forests, woodland edges, orchards, parks, and suburban yards with mature trees. Adults fly at night during late spring through summer, depending on latitude.

Its broad host plant range, including oak, maple, birch, and willow among many others, allows it to thrive in a wide variety of wooded and semi-wooded habitats.

Adults do not feed and live only about a week, devoting their short lives entirely to finding a mate. Males use their large, feathery antennae to detect female pheromones from considerable distances and fly upwind at night to locate a mate.

When disturbed at rest, the moth suddenly spreads its forewings to reveal the large eyespots on the hindwings, a startle display intended to momentarily confuse or deter predators such as birds. Caterpillars are solitary leaf feeders that consume large amounts of foliage as they grow.

Eggs are laid singly or in small groups on the leaves of a wide range of deciduous trees. Caterpillars are bright green with silvery, diagonal markings and pass through five instars, growing to roughly 3 inches before pupating.

The caterpillar spins an oval, tightly woven brown cocoon, typically dropped to the leaf litter rather than remaining attached to the host plant, within which it overwinters. Adults emerge the following spring or early summer, and depending on climate the species may produce one or two generations per year.