Investigations into Two Modes of Ultraviolet Reflectance of Pierid Butterflies

Lepidoptera (scaled-wing) are named after the scales on their wings. These scales are an innovation that gives Lepidoptera access to a very large color space beyond our human sensitivities. In addition, some butterflies are visually sensitive to ranges we are not. The ability to both sense and display a myriad of colors allows for colors to evolve signaling roles within the environment. Aposematic warning and sexual signaling are two common signaling modes used by animals and the efficacy of their transmission between receiver and sender depends on various paramteres of the color signals. Both aposematic warning colors and sexual signaling colors depend heavily on contrast within the environment to generate a conspicuous display. Pierid butterflies are known for their long-wavelength colors generated by various pterin pigments and this is reflected in common names for groups like "orange tips" and "sulfurs". Brilliant, iridescent ultraviolet patterns (IUV) are displayed by some pierids, which is generated by an intricate structure on the scale surface reflecting iridized wavelengths rather than the reflective spectral band of various pigments. Though humans cannot directly perceive these patterns, butterflies can, and sexually signaling between conspecifics evolves in species like Colias eurytheme and Eurema hecabe. While IUV seems specific to pierid butterflies, non-iridescent ultraviolet reflection is found outside of Pieridae with no functional signaling role known. Here, micro and macro evolutionary approaches reveal mechanisms and patterns of IUV evolution as well as the nature of ultraviolet reflection.

Author

• Ficarrotta, Vincent Miles

Language

• en

Keyword

• Evolution
• Butterflies
• Iridescence
• Genetics
• Ultraviolet
• Color

Date created

• 2022

Type of Work

• Dissertation

License

• All rights reserved

Rights statement

• In Copyright

GW Unit

• Biological Sciences

Degree

• Ph.D.

Advisor

• Martin, Arnaud

Committee Member(s)

• Lill, John
• Counterman, Brian
• Pyron, R. Alexander

Persistent URL

•  https://scholarspace.library.gwu.edu/etd/2227mq501