Different UV Indexes and Parallel Wing Melanization of Pieris Rapae Populations
Pieris rapae, or the cabbage white butterfly, are typically found in open and sunny land. Five to six generations can be born annually, this rapid reproduction and human migration has allowed the species to inhabit various landscapes and ecosystems across the world. Pieris rapae is known for wearing 1-3 pairs of black spots on their wings, referred to as wing melanization. This melanization is a sexually dimorphic pattern; both male and female butterflies communicate gender through their dorsal forewing spots. Many studies have provided supportive data that some Pieris rapae populations manipulate the pigmentation qualities of their dorsal wing spots (i.e.: brightness, hue, UV reflectance, size) due to inter-sexual selection; such as courtship. In this study, we will be investigating the possibility of microevolution between isolated Pieris rapae (female) populations. We will be using melanization data of the Cu3 dorsal spot (indication of a female) and the corresponding UV of the specimen’s location. A statistical correlation between melanization and UV index will be analyzed. This study could help us understand the role UV plays in inter-sexual selection and/or thermal regulation.