Fauna
Insect

Ceanothus Silk Moth

Hyalophora euryalus

Also known as Ceanothus Silkmoth, California Silk Moth

Ceanothus silk moths rank among the largest native moths in western North America, featuring rich reddish-brown wings adorned with crescent spots and a distinct white band. Adults emerge in spring with non-functional mouthparts, relying entirely on stored energy to find mates during their brief two-week lives. Large green caterpillars feed on chaparral shrubs before spinning tough silk cocoons anchored directly to host plant stems.

NocturnalLargeSilk Moth
Ceanothus Silk Moth reference1 / 7
(c) Ken-ichi Ueda, some rights reserved (CC BY), uploaded by Ken-ichi Ueda · cc-by
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Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & preyCeanothus foliage, Manzanita leaves, Willow foliage
Predators
  • Bats
  • Insectivorous Birds
  • Rodents
ThreatsHabitat loss, light pollution, pesticide use
HabitatsChaparral, coastal sage scrub, coniferous forests, oak woodlands
Life span7–14 days as adults; 1 year total lifecycle
Classification
  1. FamilySaturniidae
  2. SpeciesHyalophora euryalus
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Safe to observe at a normal distance.
Responsible observation
  • Night Lighting: Attract adults to porch lights or blacklight setups during spring evenings.
  • Winter Searching: Scan Ceanothus and manzanita stems in winter for attached silk cocoons.
  • Handle with Care: Avoid touching delicate wing scales if adults land on hands or clothing.
Related species
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