Yellow caterpillar
September 21, 2009
Once again I need your help! In June I was hiking through Zion National Park in Utah and saw this little yellow caterpillar in a Prince’s Plume flower. I have searched high and low through Caterpillars in the Field and Garden and cannot find this little guy (or gal).
I’m also including this awesome picture of a black widow I took last friday. She was posing beautifully and thought I’d share it.
Thank you for always coming through and helping me!
Zion National Park, Utah

Unknown Caterpillar from Utah

Becker's White Caterpillar from Utah

Hi Holly,
Sadly, we don’t recognize your caterpillar, and we are a bit pressed for time, so we cannot immediately research this.  We are posting your letter and photo in the hope that that one of our readers might assist you.  Since the range of the Prince’s Plume Flower, Stanleya pinnata, is listed as Southern Utah, we expect that the caterpillar might be relatively easy to identify if it is associated with the plant.  Here is more information on the Prince’s Plume Flower.

Thanks to Karl’s comment, we now know that this is a Becker’s White (Pontia beckerii) caterpillar (family Pieridae).

Update from Keith Wolfe
September 26, 2009
Hi Daniel,
Hello Holly,
For more excellent Utah photos of the Becker’s White:
In California, where I live, this species also utilizes Bladderpod (Isomeris arborea, family Cleomaceae), and similar to other butterflies whose larvae feed on plant inflorescences, it completes development in relatively few days (egg 3, caterpillar 14, chrysalis 6).
Best wishes,
Keith Wolfe

2 Responses to Becker's White Caterpillar

  1. kkroeker says:

    Hi Holly:

    Your photo is a little bit fuzzy but it looks like it is probably a Becker’s White (Pontia beckerii) caterpillar (family Pieridae). It can be found in arid inter-montane valleys from southern British Columbia to Baja California. The larvae generally feed on the flowers and flower buds of plants in the mustard family (Brassicaceae); including Stanleya pinnata where that plant occurs. You can go to: for photos of larvae and adults. Regards.


  2. Holly says:

    Thank you kkroeker! That was my caterpillar. I’m guessing since I caught it shedding the old skin that this is still a pretty early instar. It looks like it loses that beautiful yellow color later on.

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