Colorful Inchworm may be Meris alticola

Subject: Colorado Caterpillar
Location: 11 mile Canyon outside of Lake George, Colorado
June 23, 2016 8:10 am
Hey Bugman!
I have no idea what kind of caterpillar this is! Or what kind of moth/butterfly it will become. I tried all of my bug books and online resources.
This little guy was found in 11 mile Canyon in Colorado.
Thank you!
Signature: Frankie

Barberry Geometer
Colorful Inchworm:  Meris alticola perhaps

Dear Frankie,
Because of the reduced number of prolegs, your caterpillar is easily identified as an Inchworm or Spanworm in the family Geometridae, though its colorful markings make it unusual in that family, most of whose members have caterpillars that are green or brown and effectively mimic twigs.  At first we thought we had correctly identified your Inchworm as a Barberry Looper or Barberry Geometer,
Coryphista meadii, based on this BugGuide image, but we remembered identifying a similar Inchworm in the past and we could not find one in our archives.  We searched our archives for “colorful Inchworm” and we found this posting of Meris paradoxa that looks possible as well, but the species is only reported from Southern Arizona according to BugGuide.  The related and similar looking Meris alticola is also pictured on BugGuide, and it is reported on BugGuide from Colorado, so of the three, our money is on Meris alticola

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