Feeding habits of Lepidoptera are sometimes categorized into two feeding guilds, flower-visitors (nectar feeders) and non-flower-visitors (sap and rotting fruit feeders). The structure of the proboscis tip of non-flower-visitors (brush-like) has an adaptive value, facilitating fluid uptake from surfaces; however, the adaptive value of smooth proboscises of flower-visitors is understudied. This study’s purpose was to quantify the overall hydrophobicity of the drinking region of proboscises of flower- and non-flower-visiting butterflies and provide evidence for the potential adaptive value of a smooth proboscis. We used Nile red to stain the hydrophobic structures on proboscises of butterfly species from both feeding guilds. Stained proboscises were imaged on a confocal microscope and the percent hydrophobicity was quantified using Lenseye® color analysis. Our results indicate that smooth proboscises are more hydrophobic than brush-like proboscises. The hydrophobic nature of smooth proboscises might aid in retrieval of nectar from floral corollas by having less adhesive surfaces.
Kristen Reiter is a fourth year student at Kent State Stark. She is completing her bachelor’s of science degree in anthropology with a focus on biological anthropology and a biological sciences minor. After graduation, she plans to attend graduate school to become a professor conducting research on human evolution and early hominins.