Giant Silkmoth Caterpillars

Subject: Beautiful Green Caterpillar
Location: Southern Oregon
September 22, 2016 8:55 pm
Hello Bugman!
I found two beautiful, large, green caterpillars in my yard (mid July). I was thinking maybe they’re Luna Moth Caterpillars but they don’t have any red on them as some of the pictures I found do.
Can you tell me what they are? I took both of them out of the way and placed them on Oak Trees hoping that wasn’t a mistake but worried that they may otherwise be harmed.
Also, I want to write an article for our local paper about helping beneficial insects during the fall. I welcome any advice you have (especially about preserving some leaf litter for insects), and I will gladly quote you and ideally drive more traffic to your site.
Thank you!
Signature: Kenda

Silkmoth Caterpillar
Silkmoth Caterpillar

Dear Kenda,
These are Giant Silkmoth Caterpillars from the family Saturniidae and the genus Hyalophora.  There are two species from the genus in Oregon.  We are requesting assistance from Bill Oehlke to verify their species identity.

Silkmoth Caterpillar
Silkmoth Caterpillar

Bill Oehlke Responds
In southeastern Oregon they should be Hyalophora columbia gloveri. In southwestern Oregon, they should be Hyalophora euryalus.
There are hybrid blend zones in some areas and it is very difficult in some cases to differentiate even between adult moths whether they are [H.] euryalus, [H.] columbia gloveri or a naturally occurring hybrid strain.

Awesome! Thank you! Are they pollinators?

Caterpillars are not considered pollinators in the traditional sense of the word, but we would not rule out that they might accidentally transfer pollen from one blossom to another while eating leaves.  Adult Giant Silkmoths do not feed, so they are not considered pollinators.

That’s great information, thank you Daniel.
So, here’s a potentially silly question, what value do the adult moths bring to biodiversity?

We have a long-standing mission on our site to promote the interconnectivity of all forms of life on our planet.  While they are Caterpillars, Giant Silkmoths store vast quantities of fat in their bodies to help them survive as adults which do not eat.  Adult Giant Silkmoths provide a valuable source of nutrition to many predators, including bats, birds and mammals.

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