Comparative study on nanostructured order–disorder in the wing eyespots of the giant owl butterfly, Caligo memnon. Issue 7 (14th June 2018)

• Record Type: Journal Article
• Authors: Sackey, Juliet; Berthier, Serge; Maaza, Malik; Beuvier, Thomas; Gibaud, Alain
• Is Part Of: IET nanobiotechnology. Volume 12:Issue 7(2018)
• Page Start: 951
• Page End: 955
• Publication Date: 2018-06-14
• Subjects: scanning electron microscopy -- pigments -- zoology -- biological techniques -- image processing -- Fourier transforms; giant owl butterfly -- big wing eyespot -- electron microscope image -- nanostructured ridges -- nanostructured order–disorder -- Caligo memnon -- SEM image autocorrelation -- Fourier transform -- melanin pigment; Biotechnology -- Periodicals; Nanotechnology -- Periodicals; 660.6
• DOI: 10.1049/iet-nbt.2017.0320
• Languages: English
• ISSNs: 1751-8741

Abstract

Abstract : A characteristic feature of the giant owl butterfly, i.e. Caligo memnon, is its big wing eyespot. This feature could serve as deceiving functionality for the butterfly against predators. As evidenced by scanning electron microscope (SEM) image on black part of eyespot, the scales on wing eyespot contain nanostructured ridges and cross‐ribs. Applying direct measurement, statistical method, and Fourier analysis, the authors evidence that these nanostructures display order–disorder in their shape and position. The autocorrelation of SEM image provides average values of characteristic periods of the order–disorder nanostructures together with an estimation of corresponding correlation lengths. Linecuts obtained from the Fourier transform of SEM image were also analysed with the Hosemann function to extract similar information. These analyses indicate that the nanostructured order–disorder may contribute to blackness on wing eyespot. The authors thus conclude that the blackness on wing eyespot of C. memnon could be attributed to contributions from both the nanostructured order–disorder and melanin pigment.