What is this Moth?
Thu, Mar 19, 2009 at 2:29 PM
this moth was hanging on the window screen of our house from about 7am when i first noticed it, and was there all day and disappeared sometime in the night after 11pm. it was almost 5 inches wide (as seen in the picture) and very rusty/red. we live about an hours drive south of San Fransisco, California, and about a 30 minute drive from the beach. our house is in the Santa Cruz mountains, about 600ft elevation. this is easily the biggest and most colorful moth I’ve seen (although I’m only 17 and havent seen much) and i would love to know what it is
Will Lawton
Redwood Forest, in the mountains, near the ocean

Ceanothus Silk Moth

Ceanothus Silk Moth

Dear Will,
Congratulations on your sighting of a Ceanothus Silk Moth, Hyalophora euryalus, one of the Giant Silk Moths.  It is wonderful that you included both and open winged and closed winged shot and also that your included a ruler.  All of this will assist our West Coast readers who should begin sighting this moth now that spring is approaching.  According to BugGuide:  “adults fly from January to July, depending on altitude, latitude, and seasonal variation”  and  the species ranges from “British Columbia to western Montana, south through west coast states to Baja California. In California, found mostly west of the Sierras. Habitat coastal areas, chaparral, intermontane valleys, conifer forests.”  The caterpillars feed on a variety of leaves including the California lilac or Ceanothus.  Adults do not feed.

Ceanothus Silk Moth

Ceanothus Silk Moth

9 Responses to Ceanothus Silk Moth

  1. Sherry says:

    I found an injured ceanothus silk moth on February 19. His right wing is limp. I put him in a sheltered outdoor plant. Is there anything I can do for it?! I read that the moth doesn’t need to eat. Do I just wait for him to die? What do you think is the most humane thing to do?

    • bugman says:

      If the moth is a female, she may still be able to mate despite the injury. We are in favor of letting nature takes its course.

  2. Julie Terry says:

    I recently encountered the Ceanothus Silk Moth at my home in Northern Nevada. At first people told me it was a sphinx moth, but it didn’t look like any of the pictures I found. I just stumbled onto a picture of exactly what it looked like with the fuzzy body and cool antenna. He/she had a beautiful burgundy color, but I wonder if it was lost. It hung out for 3 days undisturbed on my wood fence and then disappeared. It truly was a beautiful moth and I am so glad it isn’t related to tomato worms because those things are pure ugly and gross. It was a treat to see it.

    • Joseph E. says:

      What part of Nothern Nevada did you find it in? I haven’t seen any specimens at the UNR museum, but I feel that they spread down in the hilly areas by Verdi, Mayberry Park, near Peavine Peak, and all the higher elevations in west and south Reno, Carson City, and Minden/Gardnerville.

  3. Tayne says:

    I”ve seen one of these in the bitterroot mountains in montana while hiking, it was such a beautiful surprise!

    here are some good pics my partner took of it on her blog: https://pixiefruit.wordpress.com/2015/06/03/up-on-a-mountain/

    • bugman says:

      Thanks for your links and beautiful images, but alas, we cannot post the images to our site. You may submit the images using our standard submission form by clicking the Ask What’s That Bug? link on our site.

  4. Dave Osborne says:

    Found a beautiful Ceanothus Silk Moth on the front porch this evening. Odd as we are in central Oklahoma.
    Have pictures if you would be interested.

  5. Charlie says:

    There were 2 of the Ceanothus Silk Moths on our Bug Zapper
    5-08-19 at 7am. They can`t get zapped they are too large to get in. They were mating all day and the next morning.
    This morning 5-10 only one was still clinging to the Zapper.
    Later in the day it moved and is clinging to a electric wall
    outlet by the front door. The large one has a 5″ wing span, I assume it must be the female. We are in Northern Nevada in Gardnerville. I know what Ceanothus is, just never seen it here growing unless another variety of it?

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