Wrinkles enhance the diffuse reflection from the dragonfly Rhyothemis resplendens

Area of Science:

• Structural coloration in insects
• Biophysics of light scattering
• Odonata wing morphology

Background:

• Dragonfly wings exhibit structural coloration due to multilayer nanostructures.
• The dragonfly Rhyothemis resplendens displays a deep blue hindwing color.
• Wing membrane multilayer structures can be flat or exhibit surface wrinkling.

Purpose of the Study:

• To investigate the optical properties of wrinkled multilayer structures in Rhyothemis resplendens hindwings.
• To compare light backscattering from wrinkled versus flat multilayer structures.
• To determine how wing surface morphology affects visual conspicuousness.

Main Methods:

• Comparative analysis of wing membrane nanostructures in Rhyothemis resplendens and Matronoides cyaneipennis.
• Measurement of backscattered light angles from natural multilayer structures.
• Quantification of the angular range of reflection from wrinkled and flat surfaces.

Main Results:

• The hindwings of Rhyothemis resplendens possess wrinkled multilayer nanostructures.
• Wrinkling increases the angle of backscattered light compared to flat multilayer structures.
• Reflection from R. resplendens spans 1.47 steradians (±40°), significantly broader than specular reflection.

Conclusions:

• The 'wrinkled' nanostructure in R. resplendens hindwings enhances structural color visibility.
• Increased backscattering angles improve conspicuousness over a wider viewing range.
• Wing surface morphology plays a crucial role in insect visual signaling.