Location: Cascades Mountains
June 27, 2015 10:51 am
Hi, I found several black-and-white butterflies flying around some damp soil at the 4200-ft. elevation of Mt. Rainier in Washington state on June 26. I photographed one of them; not a great shot, but I hope it shows the essentials. Can you tell me what it is? Thanks.
This is not a butterfly, but a diurnal Geometrid Moth in the genus Rheumaptera. Based on this BugGuide image, we believe it may be Rheumaptera subhastata, but it may be a different species, because according to BugGuide: “The variation in pattern among individuals of R. hastata and R. subhastata is much greater than the variation between the two species. … Since these two species have virtually identical geographic ranges, examination of genitalia is the only reliable way to separate the two.”