Flightless Female Moth from Alaska: Possibly Lycia species

Subject: Confused in Alaska!
Location: Fairbanks, AK
April 27, 2015 7:18 pm
Hello! Hope your spring has brought all sorts of buggy critters your way. My son found the strangest bug crawling across the leaf mould beneath some willows. My first thought was, could this be a half-pupated butterfly? She had a body like a short fat fuzzy grub (I could see pale green flesh in between the abdomen ridges when she flexed), butterfly-looking legs that pranced, and what appeared to be little fuzzy wing nubs. She had a very tiny head with no proboscis or discernible features, only spindly antennae.
What is she?
Thanks for your help!
Signature: Rebecca Frenzl

Dear Rebecca,
What we know for certain is that this is a flightless female moth, and we have done considerable research, and though we do not have a definitive response, we believe we are close.  The Moth PHotographers Group has a page devoted to flightless female moths.  Our first research took us to the possibility that this might be one of the females in the genus Orgyia, the Vapourers or Tussock Moths, and the Douglas Fir Tussock Moth, Orgyia pseudotsugata, is found in Western Canada, so we thought that might be a good candidate, but based on the images posted to BugGuide, the legs and antennae are much shorter than your individual.  Though images of flightless female moths can be difficult to find online, a look at the mounted pair of Douglas Fir Tussock Moths on Forestry Images confirmed our belief that it was not your species or genus.  We next turned our attention to the genus Lycia in the Spanworm family Geometridae, and the Stout Spanworm seemed like a good candidate as it is found in Western Canada, according to BugGuide, but alas, BugGuide only has images of males with wings pictured.  The Belted Beauty, Lycia zonaria, which is pictured on the Highland Butterflies UK site looks like a good match physically, but it is an old world species and the markings are different.  Except for the markings which are different, the Belted Beauty pictured on UK Moths also looks quite similar to your individual.  We are concluding that since the genus Lycia is represented in Canada by two species according to BugGuide, and both the Stout Spanworm and the Twilight Moth, Lycia rachelae, are reported from western Canada, that one of those species is most likely your flightless female moth, but alas, we had no luck finding any online images of females to compare.  Perhaps one of our readers will have more luck than we have had.