Action of the saproxylic scarab larva Cetonia aurataeformis (Coleoptera: Scarabaeoidea: Cetoniidae) on woody substrates

Abstract

The saproxylic beetle Cetonia aurataeformis Curti (Scarabaeoidea: Cetoniidae) is a common Iberian species, whose larvae develop in tree cavities feeding on wood and litter. The aim of this paper is to analyse how the larvae of this cetonid modify the woody substrate by feeding and what the ecological implications on their microhabitat could be. Thermal analysis and infrared spectroscopy have been used to study the changes suffered by different substrates, litter and wood of Betula alba and Quercus pyrenaica, after digestion by the larvae. Results show that larvae of C. aurataeformis are able to digest polysaccharides and lignin producing a residue richer in nutrients than the original substrate and with an organic structure that contains a fraction of lignin that is easier to decompose. The main conclusion is that the action of cetonid larvae on woody substrates could facilitate their use by other saproxylic organisms in natural ecosystems.

Keywords:

• FTIR
• lignin and polysaccharides degradation
• nutritional ecology
• TG
• wood transformation

Acknowledgements

We thank the staff of the National Park of Cabañeros for facilitating our fieldwork. The research was supported by the CGL2008-04472 and CGL2009-09656 projects. K. Burke helped with the English version.