We encounter many people during the course of a day, usually noting the unique features of each one of them. Some of us are better at that than others. Many of us, as is true of many police officers, are especially skilled at noting specific features of people they interact with.

Do we demonstrate that same skill when we see butterflies? My experience in the field, and  when I deliver a Powerpoint presentation, is that few people notice differences among butterflies of the same species. Here we view 2 Red-spotted purple butterflies, both seen at Raccoon Creek State Park in southwestern Pennsylvania. This species is well-known for having much variation from one butterfly to the next.

1. Which has suffered the greatest loss of wing scales?
2. Which has a pair of white marks at the very top of the head?
3. Distinct white marking at the front ends of each forewing?
4. Wider and more starkly black streaks along the outer margins of the hindwings?
5. A single red streak near the front-middle edge of each forewing?
6. White spots on the dorsal surface of its abdomen?
7. Darker forewings?
8. More sharply defined blue areas in the hindwings?

Jeff