Exploring the Relationship Between Wing Melanization, Morphology, and Environmental Variation in Pieris rapae Using Museum Specimens and Earth Monitoring Data
Presenter: Zaley G. DelRio
Faculty Sponsor: Kathryn Weglarz
School: Westfield State University
Research Area: Biology
ABSTRACT
Pieris rapae, or the cabbage white butterfly, is a widespread species recognized for its
distinctive wing pattern and agricultural impact. Beyond its role as a crop pest, P. rapae is a
valuable model organism for studying environmental effects on morphological traits,
particularly wing melanization and shape. Darker wing regions are important for
thermoregulation, offering advantages in warm climates. We investigated whether
environmental conditions, specifically latitude and temperature, drive phenotypic variation in
wing melanization and size across P. rapae populations. To assess these patterns, we conducted
a comparative analysis using museum specimens sourced from iDigBio.org. We measure
melanization area and wing dimension using Image J. Environmental data, including latitude and
local temperature, were collected using QGIS and data from NASA, for a total of 1037 specimens
with collection dates ranging from 1800 to 2024. Regression models showed weak associations
and high p-values, indicating limited influence of latitude on melanization or wing size. Similarly,
temperature was not a significant predictor of temperature and Melanization, that is
melanization levels. Findings suggest that other factors, such as genetic diversity, may play a
substantial role in shaping morphological differences. Our work highlights the utility of digital
collections for broad-scale morphological research, particularly when combined with data from
whole earth monitoring initiatives. By leveraging satellite data and historical and geographically
diverse specimens, we were able to explore phenotypic plasticity without the limitations of