Authors: Fritz Vollrath Donald Edmonds
Publish Date: 2013/12/10
Volume: 100, Issue: 12, Pages: 1163-1169
Abstract
The gluecoated and wet capture spiral of the orb web of the garden cross spider Araneus diadematus is suspended between the dry silk radial and web frame threads Here we experimentally demonstrate that the capture spiral is electrically conductive because of necks of liquid connecting the droplets even if the thread is stretched We examine how this conductivity of the capture spiral may lead to entrapment of charged airborne particles such as pollen spray droplets and even insects We further describe and model how the conducting spiral will also locally distort the Earths ambient electric field Finally we examine the hypothesis that such distortion could be used by potential prey to detect the presence of a web but conclude that any effect would probably be too small to allow an insect to take evasive actionWe thank the Science and Engineering Research Council of the UK for funding the original study in 1985 and the Air Force Office of Scientific Research FA95501210294 and European Research Council 324607 for funding the recent followup analysis by FV FV also thanks a patient editor four excellent anonymous reviewers and Sebastien Neukirch for helpful comments Donald Edmonds sadly passed away last year after a long illnessLegend A section of Araneus diadematus capture thread is observed under a microscope seconds after it has been deposited in the web under RH of 55 The thread shows the swelling of the coating followed rapidly by the formation of individual droplets evenly spaced MP4 43026 kbLegend Film showing the distortion of an orb web of Araneus diadematus by a metallic sphere of radius 5 mm charged to a voltage of 5 kV In a the Voltage is positive and in b it is negative demonstrating that the neutral but electricityconducting web is equally attracted to the charged sphere in both cases MP4 64550 kb
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