The existence of "white form male" Colias eurytheme/philodice
Colias eurytheme and C. philodice are abundant species in Pennsylvania, and females of both species come in both a "yellow" form and a "white" form, in similar proportions. In 2001, on a visit to the Penn State University entomological collection, I was surprised to see a male specimen of Colias eurytheme/philodice from Pennsylvania that had all the yellow/orange on the wings replaced by white, like a white form female. The black scaling was not faded at all, but the yellow was entirely missing. I was amazed by this specimen, and hoped that one day I might find one like it myself.
Fast-forward to 2021- I was sorting the specimens in the Fort Indiantown Gap Lepidoptera collection, and I found two more of these "white form males", both of which were collected in the mid-2010s. The labels indicated that they had both been collected in bee bowls, and neither one was in great condition, but they were apparently the same form I'd seen 20 years earlier in the Penn State collection. One of them had a little bit of orange near the costa of the hindwings, and the other had no yellow/orange at all.
This summer (2023), I started using bee bowls to sample my property for pollinators, and was surprised to find several apparently "white form male" Colias in my bee bowls. But it quickly occurred to me that these were specimens that had been soaked in soapy water and exposed to direct sunlight for several days- likely, it seems, that they simply had been bleached by these conditions. After soaking the specimens in alcohol to clean off the soapy water, softening them, and spreading them, here's what I ended up with:
https://www.inaturalist.org/observations/173267124
Basically identical in color to the specimens I'd seen at Indiantown Gap, and, but for the small patch of orange remaining on the hindwing costa, identical to the one I'd seen at Penn State.
Given that the white specimens from Indiantown Gap were bee bowl specimens, mine are bee bowl specimens, and I've never seen a live photo of this form, I'm now questioning whether this form is a thing at all. I've found other pinned specimen photos online of them, like this one:
https://bugguide.net/node/view/503074
But never a freshly eclosed, non-faded living individual. If anyone has seen such a thing, I'd love to know about it. Otherwise, I'm leaning toward concluding that this is just an odd specimen-fading quirk, and not an actual genetic aberration. I'd love to be wrong though.
