QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online January 31, 2006
Journal of Experimental Biology 209, 722-730 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02065

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Barbakadze, N. Articles by Arzt, E. Search for Related Content PubMed PubMed Citation Articles by Barbakadze, N. Articles by Arzt, E. Social Bookmarking                         What's this?

Local mechanical properties of the head articulation cuticle in the beetle Pachnoda marginata (Coleoptera, Scarabaeidae)

N. Barbakadze, S. Enders^*, S. Gorb and E. Arzt

Evolutionary Biomaterials Group, Department Arzt, Max-Planck-Institute for Metals Research, Heisenbergstr. 3, 70569, Stuttgart, Germany

^* Author for correspondence (e-mail: enders{at}mf.mpg.de)

Accepted 27 December 2005

Insect exoskeleton (cuticle) has a broad range of mechanical properties depending on the function of a particular structure of the skeleton. Structure and mechanical properties of the specialised cuticle of insect joints remain largely unknown to date. We used scanning (SEM) and transmission electron microscopy (TEM) to obtain information about the material structure of the gula plate, the head part of the head-to-neck articulation system in the beetle Pachnoda marginata. The surface of this cuticle appears rather smooth in SEM. The fibers of the exocuticle are partly oriented almost perpendicular to the surface, which is rather unusual for arthropod cuticle. Nanoindentation experiments were performed to determine the local mechanical properties (hardness and elastic modulus) of the gula material. To understand the effect of desiccation and the influence of an outer wax layer on the mechanical behavior of the material, the samples were tested in fresh, dry and chemically treated (lipid extraction in organic solvents) conditions. Nanoindentation results were found to be strongly influenced by desiccation but only slightly by lipid extraction. Decreasing water content (15-20% of the cuticle mass) led to an increase in hardness (from 0.1 to 0.49 GPa) and elastic modulus (from 1.5 to 7.5 GPa). The lipid extraction caused a slight further hardening (to 0.52 GPa) as well as stiffening (to 7.7 GPa) of the material. The results are discussed in relation to the mechanical function of the gula plate.

Key words: desiccation, gula plate, insect cuticle, mechanical property, nanoindentation

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				M. Muller, M. Olek, M. Giersig, and H. Schmitz Micromechanical properties of consecutive layers in specialized insect cuticle: the gula of Pachnoda marginata (Coleoptera, Scarabaeidae) and the infrared sensilla of Melanophila acuminata (Coleoptera, Buprestidae) J. Exp. Biol., August 15, 2008; 211(16): 2576 - 2583. [Abstract] [Full Text] [PDF]

				M. E McConney, C. F Schaber, M. D Julian, F. G Barth, and V. V Tsukruk Viscoelastic nanoscale properties of cuticle contribute to the high-pass properties of spider vibration receptor (Cupiennius salei Keys) J R Soc Interface, December 22, 2007; 4(17): 1135 - 1143. [Abstract] [Full Text] [PDF]