REPUBLIC OF SERBIA

MINISTRY OF DEFENCE

www.mod.gov.rs

MINISTRY OF DEFENCE

Material Resources Sector

Defensive Technologies Department

Military Technical Institute

www.vti.mod.gov.rs

THermal and camouflage properties of rosalia alpina LONGHORN BEETLE with structural coloration

Ivana KostIĆ

Technical Test Center, Belgrade, kostic.ici@gmail.com

danica pavlOVIĆ

Photonics Center Institute of Physics, University of Belgrade, danica.pavlovic@ipb.ac.rs

vladimir lazovIĆ

Photonics Center Institute of Physics, University of Belgrade, vladimir.lazovic@ipb.ac.rs

darko vasiljevIĆ

Photonics Center Institute of Physics, University of Belgrade, darko@ ipb.ac.rs

deJAN stojaNOVIĆ

Fruška Gora National Park, Sremska Kamenica, dejanstojanovic021@yahoo.co.uk

Dragan KneževIĆ

Military Technical Institute, Belgrade, dragankn@gmail.com

LJUBIŠA TOMIĆ

Military Technical Institute, Belgrade, ljubisa.tomic@gmail.com

GORAN DIKIĆ

Military Academy, University of Defence in Belgrade, goran.dikic@mod.gov.rs

dejaN panteLIĆ

Photonics Center Institute of Physics, University of Belgrade, pantelic@ipb.ac.rs

Abstract: Rosalia alpina is a longhorn beetle possessing distinctive gray body with several black spots. They serve as a camouflage within its environment (beech forest) and we suppose that insect also uses them to control the body temperature. We have studied the optical properties of this particular insect, ranging from the visible to far infrared part of the spectrum. Optical analysis has shown strong absorption in the visible, while thermal camera (operating in the spectral range from 7.5 to 13 μm) has shown quite uniform emissivity of the whole body. Numerical ray tracing was used to explain the exact optical mechanism of strong absorption of black spots. Possible military applications of the natural camouflage and absorption mechanism are outlined.

Keywords: Infrared imaging, natural photonics, camouflage.