It was reported that when the eminent scientist J.B.S. Haldane was asked whether his studies suggested the existence of God, he replied ‘The Creator, if he exists, has an inordinate fondness of beetles’! That being so, He/She would surely have been enamoured with Cetonia aurata, the Rose Chafer.
This beautiful green and bronze metallic beetle may be found on sunny, summer days feeding on the pollen and nectar from dog roses and other flowers. The female chafer lays her eggs in decaying vegetable matter on which, after hatching, the emerging larvae feed. The larvae moult a number of times over the next few years until they are ready to pupate. Pupation occurs in soil or rotting wood, and the adults usually emerge during the following spring and early summer when mating occurs.
The iridescent colour of these beetles is the result of the complex structure of the outer layer of the hard cuticle that forms their exoskeleton. The surface of the cuticle is composed of multiple, microscopically thin, layers and ridges (see close-up of an elytrum or wing-case) which act like lenses to interfere with the reflection of different wavelengths of light - some wavelengths being trapped and others being redirected. This means the colour varies with the viewing angle and light direction (see photograph indicating that the specimen appeared to be a bronze colour under overhead lighting, yet green under horizontal lighting). Research has indicated that the beetle can be camouflaged in fluctuating light, when either it, or a potential predator, moves or it is resting against a background of glossy vegetation!
