Controlled fluorescence in a beetle's photonic structure and its sensitivity to environmentally induced changes

Area of Science:

• Biophotonics
• Materials Science
• Insect Morphology

Background:

• The Hoplia coerulea beetle's elytra possess intricate photonic structures.
• These structures contain fluorophores and control both reflected light (color) and fluorescence emission.
• Understanding environmental influences on these optical properties is crucial.

Purpose of the Study:

• To investigate the impact of water on the fluorescence emission of Hoplia coerulea beetle elytra.
• To analyze the relationship between structural changes and optical responses (fluorescence and reflectance).

Main Methods:

• Experimental observation of fluorescence and reflectance peak wavelengths before and after water immersion.
• Time-resolved fluorescence measurements.
• Optical simulations to model light emission mechanisms.

Main Results:

• Water immersion caused a blue-shift in the fluorescence emission peak wavelength.
• Simultaneously, a red-shift was observed in the reflectance peak wavelength.
• Optical simulations and time-resolved measurements indicated a shift from radiative to non-radiative emission pathways in wet elytra.

Conclusions:

• The photonic structure of Hoplia coerulea elytra actively modulates fluorescence emission.
• Water alters the optical response by changing the dominance of radiative versus non-radiative relaxation pathways.
• This highlights the dynamic nature of bio-photonic structures in response to environmental stimuli.