Subject: Fritillary ID
Geographic location of the bug: Oregon, Fall River (near Bend)
Time: 12:39 PM EDT
Your letter to the bugman: Can you help identify this fritillary butterfly. I had no idea how difficult they are to identify. I can’t determine if this is hydaspe or maybe zerene or perhaps a different species. Thank
How you want your letter signed: Bruce Carlson
Thank you for including both a dorsal and ventral view. Fritillary identification can indeed be quite challenging, but we believe it might be the Zerene Fritillary, Speyeria zerene. According to Butterflies Through Binoculars, The West, the Zerene Fritillary is “mid-sized fritillary that is extremely variable.” The difficulty in distinguishing different species of Fritillaries from one another is further exacerbated by the extreme variability many species exhibit. Here is a BugGuide image of a dorsal view for comparison and also a ventral view from BugGuide. We would defer to any Fritillary experts on this matter.
Update: January 24, 2020
Subject: Update on fritillary ID
Your letter to the bugman: Last year I submitted a photo that you tentatively identified as Speyeria zerene. I now have positive ID that it is Speyeria zerene zerene: “Hey Bruce – We have a positive ID from the experts… you did observe S.z.zerene. See exchange below with USFWS.
Well, I consulted THE expert, Paul Hammond, and he said it was in fact S. z. zerene. He did indicate the following: “Speyeria z. zerene is distinguished from sympatric S. hydaspe by subtle differences in the wing color pattern, but they are often difficult to distinguish. ” You can pass this along as a positive id. Rich