Entoma
Ramie moth, Arcte coerula, plate

Erebid moths

Arcte coerula

Ramie moth

This moth's dark brown forewings are speckled with silvery blue scales, and its hindwings carry a bright blue patch that stays hidden until it takes flight.

WhereNettle family shrubland and forest edges
Size65 to 90 mm wingspan
WhenJanuary to December

Adults are large, dark brown moths with black markings and a scattering of silvery blue scales on the forewings, scalloped wing edges, and hindwings marked with bright silvery blue patches that are hidden when the wings are folded at rest.

Caterpillars feed on ramie and other plants in the nettle family, and when disturbed they rear up the head, thrash from side to side and bring up a green fluid to deter predators. In warm parts of its range, adults can be found flying throughout the year.

Traits

Habitat

Woodland

Colour

Brown, Blue

Active

Night

To people

Adults do not sting or bite and are harmless to people; only the caterpillar's defensive display and fluid are meant for predators, not for humans.

Activity through the year

Often confused with

Ophiusa disjungensnot in guide
Ophiusa disjungens

Has an orange hindwing with only a small, reduced black patch, unlike the black hindwing with a bright blue patch carried by the Ramie moth.

Questions

Is the Ramie moth dangerous to people?

Adults do not sting or bite and are harmless to people; only the caterpillar's defensive display and fluid are meant for predators, not for humans.

When can you see the Ramie moth?

The Ramie moth can be seen from January to December, at night.

Plate retouched from a museum specimen photo by Taiwan Biodiversity Research Institute, CC BY 4.0, GBIF Licence

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Butterflies and moths›Erebid moths›Arcte

Last updated 2026-09-27. Every entry is checked against published sources.