Super black eyespots of the Eyed elater

Abstract

Scattering of light by surface structures leading to near complete structural absorption creates an appearance of “super black.” Well known in the natural world from bird feathers and butterfly scales, super black has evolved independently from various anatomical structures. Due to an exceptional ability to harness and scatter light, these biological materials have garnered interest from optical industries. Here we describe the false eyespots of the Eyed elater click beetle, which attains near complete absorption of light by an array of vertically-aligned microtubules. These cone-shaped microtubules are modified hairs (setae) that are localized to eyespots on the dorsum of the beetle, and absorb 96.1% of incident light (at a 24.8° collection angle) in the spectrum between 300 – 700 nm.

Peer Review #1 of "Structure and pigment make the eyed elater’s eyespots black (v0.1)"

“…We are grateful to Charity Hall for editing previous versions of the manuscript, and anonymous reviewers for suggestions and improvements. Data accessibility R script, uncompressed image files, and TXT text file spectral data are available to download from VTechData [29], https://data.lib.vt.edu/collections/rf55z781b…”

Super black eyespots of the Eyed elater

“…Data accessibility R script, uncompressed image files, and TXT text file spectral data are available to download from VTechData [25]…”