What's That Bug? does not endorse extermination

Subject: Beautiful caterpillar
Location: In between Fernan Saddle and Wolf Lodge Creek
July 5, 2015 10:58 am
Sooo….were out huckleberry picking on Independence Day and my daughter says “Dad, check out this cool caterpillar I found”. I walk over to her and to my amazement find the coolest Independence Day caterpillar ever! It’s got red spikes, blue spikes, and white dots and they look like fire works too!
Signature: Joe Hitz

Ceanothus Silkmoth Caterpillar, we believe

Ceanothus Silkmoth Caterpillar, we believe

Dear Joe,
Your images are spectacular.  While we are certain your caterpillar is a Giant Silkmoth Caterpillar in the genus Hyalophora, we are not certain if it will become a Ceanothus Silkmoth or a Columbia Silkmoth as both species have very similar looking caterpillars.  We are leaning toward the Ceanothus Silkmoth Caterpillar,
Hyalophora euryalus, and according to BugGuide:  “Larvae feed on a number of trees and shrubs, including Red Alder (Alnus rubra), birch, Antelope Bitterbrush (Purshia tridentata), buckthorn (Rhamnus), Buffaloberry (Sheperdia canadensis), Ceanothus species, cherry, gooseberry (Ribes), Hardhack (Spiraea douglasii), hazel, Madrone (Arbutus menziesii), manzanita (Arctostaphylos), Mountain Mahogany (Cercocarpus betuloides), Mountain Maple (Acer glabrum), rose, Saskatoon Serviceberry (Amelanchier alnifolia), willow (Salix), and occasionally Douglas-fir (Pseudotsuga menziesii).”  According to BugGuide, the caterpillar:  “changes colors as it develops and molts; mid instars are the most brilliantly colored with nine pairs of dorsal yellow spines, the first three pairs with partial to complete black rings; a middorsal yellow spine on A8; two rows of lateral blue spines tipped with white along T1-A8; white-tipped blue spines also occur on the head, at the base of the true legs, and in the anal region; body ranges from green to whitish-green  later instars whitish-green with white spines.”  You can see examples of both species on BugGuide, but your individual is more brightly colored than most of the images posted there.  We will try to contact Bill Oehlke to see if he can determine the species.

Ceanothus Silkmoth Caterpillar, we believe

Ceanothus Silkmoth Caterpillar, we believe

Bill Oehlke Responds
Daniel,
Idaho is a big state. It seems most like Hyalophora [euryalus] kasloensis. A more precise location would help.
There is also a hybrid zone in Idaho.
Very nice images. My first choice would have to be kasloensis, although this may only be third instar.
Bill

Thanks Bill.  the location is:  “In between Fernan Saddle and Wolf Lodge Creek”

Daniel,
Based on location it is Hyalophora euryalus, the ceanothus silkmoth.
Please see if I can get permission to post images. I suspect it is third instar.
Bill

Ceanothus Silkmoth Caterpillar, we believe

Ceanothus Silkmoth Caterpillar, we believe

What's That Bug? does not endorse extermination
Location: Fernan Saddle, Idaho
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3 Responses to Ceanothus Silkmoth subspecies Caterpillar

  1. I am seeking permission to publish this photo of the Ceanothus Silk Moth caterpillar in the September edition of our magazine. We would of course credit the photographer Thank you.

    Signature: Melissa Wynn

    • bugman says:

      Hi Melissa,
      What’s That Bug? grants permission to reproduce this image of a Ceanothus Silkmoth Caterpillar in your magazine. We will forward a higher resolution file to you. Please credit the photographer and add courtesy of What’s That Bug?

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