Two-striped Emerald Moth

Nemoria bistriaria

May 5, 2007

As if identifying moths wasn’t hard enough… 

Here’s a pale brown little geometer that goes by the name “Emerald”.  Why?  Because the second brood population is rich green in color.  However, the first brood, or “spring form”, is brown.  My guess, and I do a lot of guessing on this site, is that the brown form works more crypitically for the species when the surrounding area has yet to leaf out.  Come summer, when green prevails, the green form blends in better.  And it behooves a tasty little moth to blend into the background when birds are looking for a meal.

I really don’t see this strategy – two distinct seasonal color forms – employed that frequently in the moths.  I hope to add a picture of that green form to this site this summer.