Insect identification is unfair.
I came across this photo yesterday while looking through some images from last summer. The photo caught my eye and I thought maybe I’d write a short natural history blurb about it and use that as my “Photo of the Week”. My first task was to figure out what kind of butterfly is in the photo. No problem. I’ve got field guides and the internet. How hard could it be?
A small butterfly uses its long tongue to extract nectar from common milkweed at our family prairie near Stockham, Nebraska. If you click on the photo you can look at a larger version of the image and get a better look at the tongue.
I’m no butterfly expert, but I spent parts of a few summers learning butterflies back in the late 1990’s and have held on to much of my knowledge from that time. I can usually identify the more common butterflies by sight and narrow others down enough that I can pretty quickly use a field guide to finish the job. Skippers can cause me some problems, but they can be difficult even for seasoned butterfly biologists. (Skippers are like the sparrows of the butterfly fauna – little brown fuzzy jobs that all look about the same.)
My first thought was that the butterfly was a pearl crescent. That’s a common butterfly species around here and it looks much like the critter in the photo. I looked it up, but the spots on the underside of the wing don’t quite match up. The butterfly in the photo has more white patches than those in the field guides and online.
Next, I looked at the Gorgone’s checkerspot, another species we see quite a bit here. No luck there either. The patterns on the underside of the wings are really different from the butterfly in my photo. I looked at the “Butterflies of Nebraska” and “BugGuide” websites and browsed through a number of other choices, including some species that only show up occasionally in the state. Still no luck. Frustrated, I left for a meeting, figuring I’d try again later.
By complete coincidence, my meeting today was about pollinator monitoring strategies, and the first two people I ran into were both butterfly experts. Aha! Since we had a few minutes before the meeting started, I grabbed my laptop and pulled up the photo in question. They both stared at it, but neither gave me a quick answer. I felt both better (it’s not just me!) and worse (come on, man, this isn’t supposed to be this HARD!).
After some hemming and hawing, the conclusion was that it’s probably some kind of crescent (Phyciodes sp.) but they couldn’t do any better than that. To be fair, neither of them had access to field guides and it was a surprise question. Still… One of the biologists pointed out that not only do male and female crescents have different patterns, there can also be significant differences in patterns between different generations within the same summer. What??
As a result of all this, I’m stuck not being able to tell you much natural history about this pretty little butterfly other than it’s probably some kind of crescent. Interesting, huh? About 30 minutes of my poking around in books and online, two butterfly experts looking at my photo with me, and that’s the best we’ve got. Well, that and one unarguable conclusion:
Insect identification is unfair.
The Prairie Ecologist 
I’m going to cautiously agree with your first inclination of a pearl crescent (female). Everything seems to pretty closely fit with the photo in Glassberg’s Butterflies through Binoculars (The East). As always, a great photo, Chris!
I have had the same experience with butterflies. And a couple of Julys ago I saw either a Pearl or Phaon Crescent oviposit on a smartweed in urban Houston, way outside their normal range of hosts. It was over too quickly for me to get a photo. Sometimes a butterfly will oviposit on a nonhost plant near a host plant to protect the egg from being removed by insects that otherwise protect a host from predation. I saw this occur in Houston when a Gulf Fritillary laid an egg on a grass stalk immediately adjacent to host Passiflora incarnata, which draws ants with nectaries. But there was nothing close to the smartweed that could serve as a normal host for either Crescent species.
I’m not sure if Phaon Crescent (Phyciodes phaon) is found in NE but that is my guess, given the location of the white patches on the forewings.
According to William H. Howe, The Butterflies of North America, P. phaon occurs as far north as Kansas “It ranges from Florida north on the coast to southern Virginia, west to San Diego, California, north to Kansas, and south to Guatemala and British Honduras.”
Larval food plants are Lippia lanceolata (a type of verbena found in Missouri) and L. nodiflora (a South American plant).
Did you try posting it to Bugguide as an “ID Request?” I’ve found that feature incredibly useful.
I often feel the same way when I try to identify an unfamiliar sedge. I typically get the identification wrong the first time I try keying out a specimen. After looking at the key and descriptions over the course of about a week, and changing my mind a number of times, I usually converge on the right species. I’m sure I would be better at this if I did it more than once or twice a year.
FYI – Congratulations for being quoted in the most recent issue of Nature Conservancy Magazine
If you think your butterfly is tough to identify, read the section about rare Papaipemas (pp. 295-297) in “A Natural History of the Chicago Region.” At least you don’t have to dissect the genitalia to identify your butterfly. :)
https://books.google.com/books?id=OXA1VVOSUg4C&q=rattlesnake+master#v=onepage&q=Papaipema%20eryngii&f=false
Love these! Thanks for your passion for our prairies!!
Laura McIver | Oklahoma & Texas Regional Representative
Pheasants Forever, Inc. and Quail Forever | P.O. Box 42121 | Oklahoma City, OK 73123 | m. (907) 750-2600 | Lmciver@pheasantsforever.org | State PFQF websites: http://www.OklahomaPfQF.org | http://www.TexasPfQf.org | State Facebook Pages: http://www.facebook.com/oklahomapfqf | http://www.facebook.com/texaspfqf
Subscribe State Email Newsletters: Oklahoma http://eepurl.com/bLriKj | Texas http://eepurl.com/bLqM4D | Follow me on Twitter: @LauraMcOutdoors
________________________________