Abstract

Out of the many theories surrounding the purpose of wing melanization in butterflies, one of the most prevalent is its significance to thermoregulation. However, it is not agreed upon whether melanization reduces body temperature, increases body temperature, or has no effect at all. As climate change progresses, we hypothesize that rising temperatures will provide insight into the role of melanization in thermoregulation, if any. Increasing melanization suggests that less reflecting area is needed to increase body temperature. If melanization decreases, then the inverse is supported. Using digital collections, the melanization of P. rapae specimens (n = 487) from 1859 to 2009 was observed. Melanization was also compared between North America and Europe. Since Europe is the fastest-warming continent, we hypothesized that the melanization of inhabitants would also be related to their higher geography. Upon analysis, though there is little relationship between temporal change and melanization, we found the relationship between melanization and continent to be significant. The results offer insight into how P. rapae melanization reacts to climate change as well as melanization’s role in thermoregulation.