My Emperor Gum moth is actually a…

Photo by Native Orchids

In June I put up a post about how I thought an Emperor Gum moth had found its way from Australia to my parent’s porch in Portland, OR.  Lots of people chimed in on the comments from all over the U.S. saying that they too had found moths that looked like this.

So what was the deal here?  Are they a relatively common occurrence in the U.S. but somehow not officially documented or recognized as indigenous?  Like some kind of expatriate of insect world?

Thanks to Mirranda Haan, who found one of her own and is evidently a better bug researcher than me,  there’s a less spectacular but far more likely explanation: these moths aren’t Emperor Gum moths.  They’re Antheraea Polyphemus moths, which, to my clearly untrained eye, look almost exactly like Emperor Gum moths.