Ceanothus Silk Moth

Ceanothus Silk Moth

Hyalophora euryalus

Daily sighting probability <5% · Rare
at Portland

In 3 days ~10% in a week ~20%

17 Verified sightings at Portland
70 In all 7 parks From 2019 to 2026
April Best month
☀️ Diurnal When it's spotted

About the Ceanothus Silk Moth

Hyalophora euryalus, the ceanothus silkmoth, is a moth of the family Saturniidae. The species was first described by Jean Baptiste Boisduval in 1855. It is found in the forests and valleys of the Pacific Northwest, but has been observed as south as Baja California.

It is a reddish-brown moth with black and white patterning spots. The postmedial band and various spots are black and white. The edges of the wings vary from light brown to gray. Its antennae are fluffy and black. The wingspan is 89–127 mm. Adults are on wing from January to July depending on the location. There is one generation per year.

It is found in the dry intermontane valleys and interior of British Columbia, Canada, (as far north as Prince George along the Fraser River) south to Baja California in Mexico. A subspecies, Hyalophora euryalus cedrocensis, is found on the Isla de Cedros, a small island off the west coast of Baja California, Mexico.

Other habitats include coastal rainforests, hardwood forests, montane forests, and juniper woodlands. The larvae feed on numerous hostplants including those in the Rhamnaceae (Ceanothus, Rhamnus californica), Ericaceae... Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Redwood National Park 🇺🇸 United States
~10%
2 Sequoia and Kings Canyon National Parks 🇺🇸 United States
~10%
3 Yosemite National Park 🇺🇸 United States
~10%
4 Great Bear Rainforest 🇨🇦 Canada
~10%
5 Pacific Rim National Park Reserve 🇨🇦 Canada
~10%
6 Glacier National Park 🇺🇸 United States
~10%
7 Olympic National Park 🇺🇸 United States
<5%

Cities Where Found

# City Country Daily sighting probability
1 Portland 🇺🇸 United States
<5%
2 Vancouver 🇨🇦 Canada
<5%
3 San Francisco 🇺🇸 United States
<5%
4 San Diego 🇺🇸 United States
<5%
5 Los Angeles 🇺🇸 United States
<5%

Before you go

What are the chances of seeing a Ceanothus Silk Moth in Portland?

Rare

Under 5% of wildlife watchers report a Ceanothus Silk Moth sighting in Portland on a given day, based on 17 verified sightings from GBIF citizen-science data. It is the 269th most-seen of the 507 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.

When is the best time to see a Ceanothus Silk Moth in Portland?

April

In that month about 10% of wildlife watchers report a Ceanothus Silk Moth in Portland on a given day, against under 5% in May to March, the lowest months.

What time of day is best to see a Ceanothus Silk Moth?

Between 7 and 10 am

Across all the parks we cover, that three-hour window holds the most Ceanothus Silk Moth sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.

Is Portland the best place to see a Ceanothus Silk Moth?

Yes

Of the 5 cities where we can rate Ceanothus Silk Moth sightings, Portland has the highest daily chance: under 5%. Next come Vancouver (Canada, under 5%) and San Francisco (United States, under 5%).

Where does the Ceanothus Silk Moth sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Ceanothus Silk Moth is recorded against all the insects logged in Portland (17 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.

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