Humidity affects the extensibility of an orb-weaving spider's viscous thread droplets

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TR Number
Date
2011-09
Journal Title
Journal ISSN
Volume Title
Publisher
Company of Biologists Ltd.
Abstract

The prey-capture threads found in most spider orb webs rely on viscous droplets for their stickiness. Each droplet is formed of a central mass of viscoelastic glycoprotein glue surrounded by an aqueous covering, both of which incorporate hydrophilic components. We found that the extensibility of droplets on Larinioides cornutus threads increased as humidity increased. However, the deflection of the droplets' supporting axial lines did not change, indicating that atmospheric water uptake increases glycoprotein plasticity, but not glycoprotein adhesion. The extensibility of droplets, along with that of the thread's supporting axial fibers, is responsible for summing the adhesion of multiple thread droplets. Therefore, daily changes in humidity have the potential to significantly alter the performance of viscous threads and orb webs.

Description
Keywords
Araneoidea, biomaterial, glycoprotein, hygroscopic, Larinioides cornutus, AMPULLATE SILK FIBERS, CAPTURE THREADS, MECHANICAL-PROPERTIES, SPUN, WEB, ADHESION, WATER
Citation
Opell, Brent D.; Karinshak, Shannon E.; Sigler, Mary A., "Humidity affects the extensibility of an orb-weaving spider's viscous thread droplets," J Exp Biol 214, 2988-2993 (2011); doi: 10.1242/_jeb.055996