Here in Illinois these have been out about a month. It may be considered dirt common as a species but, I still love getting out into a field of these and the even more common C. philodice. Yellow butterflies everywhere. I've seen upwards of 300 or 400 such butterflies pollinating a single clover field or similar flowering field. Against the green backdrop of the field with maybe a distant farmhouse or barn in the far distance; the scene is just surreal. The quiet of the country along with a soft occasional breeze, blue sky, small passing fluffy clouds = tranquility. Against this scene of life and golden yellow glints of yellow in the sunlight; I carefully pick and chose my quarry -- only netting those with the boldest colors. The black amount varies as does the yellow spotting so to me it's still a worthwhile and yet fun species to seek out. You are guaranteed to always bring something back for your efforts and time. Unlike, many much harder to find species found in far lesser numbers.
This year in the Upper Midwest States (Illinois,Indiana,Wisconsin etc.); we had an especially nice hatch of 2nd brood Colias emerge in early September. The Orange Sulphur's (C. eurytheme) which I encountered had some very bold coloration. Albino form females or "Roadside butterflies" (as they have been called in literature of old); were a treat to capture as they were only occasional sightings amongst the more numerous yellow form females. One had to also look closely at the yellow form females so as not to pass up any melanic individuals or those sporting genetic mishaps. I managed one nice melanic female (right column;bottom); although I missed at least 2 others I spied on the wing. Additionally, I picked up "purely by accident" a large male (left column;bottom); sporting an asymmetrical left forewing. It is now very late September and although Colias are still "out and about"; their numbers are quite a bit less and finding choice specimens has become considerably more challenging. Lots of beaters and color worn individuals at this time.
Beautiful specimens, I must look for those melanic females next year, never saw one like it or just overlooked as they certainly look a like in flight.
PS. Trehopr you must to have a lot of guts to take your specimens with no glass outside, when I open my drawers I usually close all the windows in the room to be safe against any kind of possible draught.
Finally, after a year's wait the first examples of this gaily colored Pierid species are now beginning to appear in nearby fields. In my region, these typically begin to be seen in Mid-July sometime... I just went out afield a couple days back (July 18th) and spotted 4 fresh males on the wing. Only managed this one prime example but, they were all fresh and being quite elusive !
A common species which I like collecting because, so long as these are out I'm certain to have something nice from the field to prepare when I get home. A simply lovely species with a captivating depth of color !