In “The Princess Bride” there was an encounter with “rodents of unusual size.” Today I had an encounter with a butterfly of unusual size.
I have photographed a lot of butterflies over the past several years, and having done so I have a pretty good idea of how large each species “should” be. Having said that, every time I look at someone’s butterfly collection I am surprised at how small the butterflies seem to be. When chasing them in real life they seem much larger.
Along Saylorville Reservoir I came across a small patch of dogbane still in bloom. This is unusual in itself because the plant normally is done blooming by the first week or two of July. I saw this orange sulfur. It was quite large–large enough that I thought at first it could be a cloudless sulfur.
We have had quite a bloom of painted ladies in Iowa lately, and this individual butterfly was slightly larger than any of them. When it flew, it had bright orange on its upper surface. This orange color is not unheard of but it was quite a bit more orange than I typically see.
So it was an unusually large, unusually dark orange sulfur.
Butterflies can sometimes show striking individual size variation–today I also noticed a number of common buckeyes which were smaller than normal. I have seen eastern tailed-blue individuals, for example, that were about half the size of normal. In the butterflies that have several generations per year, one generation might be smaller, on average, than a different generation. They can also be colored significantly differently.
Speaking of size, this is one of Iowa’s smallest butterflies, the dainty sulfur. This is not seen everywhere, but can be quite common where it is found.