False Crocus/Crocus Geometer - Xanthotype

which is which?

Both species are found as far south as Georgia, so that's no help. In Canada, sospeta flies from June-September, urticaria from June- August; suggests that they probably fly together in NC - no help.
Urticaria is more northern than sospeta; I get far more urticaria here in NB than sospeta.
Colour: sospeta is always a pale yellow, urticaria is often an orange yellow (but I believe it does have a paler form). One other feature is the frequency of the spots rather than the density of them. Sospeta often sparsely spotted - so the last 2 thumbnails are most likely sospeta. Urticaria usually has more spots. So what's the 1st specimen? Orangy yellow indicates urticaria, but the spotting seems sparse and that suggests sospeta. Sometimes colours in photos are subtedly different from true colours - much better to see the colours on an actual specimen.
They are readily separated by dissection. If you want to get more photos this year and don't object to sacrificing the specimens, I will dissect them for you and give a definitive id.

… A.W. Thomas, 17 March, 2005 - 8:59am

Cool, thanks...

The colors on that first specimen are pretty close--they are all a pretty deep yellow to yellow-orange here that I've seen.
Hmm. North Carolina State Univ. has 4 "rufaria" and 14 sospeta pinned.

I'll try to catch some this summer. I'll also consult our local moth expert--he dissects, etc. when needed all the time.

Thanks for the input. Beautiful moths, whatever species they belong to.

Patrick Coin
Durham, North Carolina

… Cotinis, 17 March, 2005 - 11:57am

I should have known better

than to make a comment on id about a southern moth. Thought I was on solid ground in that McGuffin in a paper on the Geometridae of Canada lists urticaria as occurring from NS to Alberta, south to northern Georgia and west to Arizona. He quoted Rindge, a noted USA authority on the genus: Rindge. 1978. A Revision of the moth genus Xanthotype (Lepidoptera, Geometridae). Am. Mus. Novit. 2659. This would be a publication worth looking at. Seems now that perhaps urticaria from 'down south' may be something other than urticaria.

… A.W. Thomas, 17 March, 2005 - 12:45pm

Xanthotype range

Aha! Northern Georgia sounds like the mountains. There is north-woods type habitat extending southwards in the Appalachians. We don't have that here in the lower Piedmont, we have oak-hickory forest with lots of second-growth pines. This is a rather different flora and fauna than the Appalachians. It makes sense that a northern moth might not have a range this far south, and low in elevation. (Funny no records of X. urticaria from the very high North Carolina mountains--maybe nobody has ever looked.)

Patrick Coin
Durham, North Carolina

… Cotinis, 18 March, 2005 - 6:08am

Food Plants

for urticaria, as listed by McGuffin: Spiraea, Solidago, Rosa, Ribes, Comptonia, Nepeta, Glechoma, Rhododendron, Acer, Cornus, Vaccinium.

… A.W. Thomas, 18 March, 2005 - 7:11am