Butterflies and Moths of North America

collecting and sharing data about Lepidoptera

Ceanothus silkmoth
Hyalophora euryalus (Boisduval, 1855)


Family: Saturniidae
Subfamily: Saturniinae
Identification: Wings are red to brownish red. Areas outside the narrow white postmedian lines are also red to brownish red, but may have black overscaling. Cell spot on the hindwing is shaped like an elongated comma and touches or breaks the postmedian line.
Wing Span: 3.5 - 5 inches (8.9 - 12.7 cm).
Life History: Females glue eggs singly or in clumps on leaves of the host plant. The eggs hatch in 9-14 days and the caterpillars eat leaves. The cocoon is spun in the outer part of the host plant and is attached to a twig by only one-half its length.
Flight: One brood from January-July depending on altitude and seasonal variation.
Caterpillar Hosts: A wide range of plants including buckbrush (Ceanothus), manzanita (Arctostaphylos), gooseberry (Ribes), madrone (Arbutus menziesii), willows (Salix), alder (Alnus), and mountain mahogany (Cercocarpus betuloides).
Adult Food: Adults do not feed.
Habitat: A wide variety of habitats including coastal areas, chaparral, and conifer forests.
Range: British Columbia east to western Montana, south through Washington, western Oregon, and California to Baja California Sur.
Conservation: Not usually required.
NCGR: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management Needs: None reported.
Comments: NULL