Analysis of the functional morphology of mouthparts of the beetle Priacma serrata, and a discussion of possible food sources.

PublishedJournal ArticleWith the help of scanning electron microscopy, high resolution X-ray tomography (µCT), and finite element analysis, the mechanical and functional properties of the mandibles and associated muscles of the beetle Priacma serrata (LeConte) (Coleoptera: Archostemata) were studied. The combination of these techniques allowed for studying mechanical properties of the headmandible- system without using living animals. The µCT analysis delivered precise volumetric data of the geometry of the system to be studied. Dimensions of the cuticle of the parts involved could be readily deduced from the µCT-data. Thus, an exact representation of the specimen without significant artifacts like deformations and misalignments, usually resulting from histological sectioning, could be reconstructed. A virtual 3D model built from these data allowed for investigating different stress scenarios with finite element analysis. Combining these methods showed that P. serrata most likely uses its robustly-built mandibles for cutting hard material. In combination with available information on its habitat, possible food sources are discussed.The authors are grateful for the help provided by Freek Pasop of SkyScan in preparing the µCT data of Priacma serrata and for the very helpful comments on the manuscript by Benjamin Wipfler and an anonymous reviewer. A collecting trip of T. Hörnschemeyer to Montana, USA, was financially supported by the DAAD (D/96/05967). T. Hörnschemeyer was supported by a DFG Heisenberg grant HO 2306/6-1,2. T. Hörnschemeyer wishes to thank Mike Ivy, Montana State University, Bozeman, Montana, USA, for his generous general support