Insect attraction by webs of Nephila clavipes (Araneae: Nephilidae)

Although well studied, the role of spider webs in attracting prey and the role of web ornaments remain open questions. We carried out a field study to determine whether webs of Nephila clavipes (Linnaeus 1767) attract insects. Nephila builds large orb-webs with debris-decoration that host kleptobiotic Argyrodes spiders. We studied the potential prey of Nephila with sticky traps placed in two similar linear plots. One plot contained 20 Nephila webs, and the other was cleared of Nephila webs. We measured the number and size of the insects caught in the traps. We compared the size of the trapped insects with prey caught by Nephila and gleaned by Argyrodes. In the plot with Nephila webs we collected 314 individuals versus 105 individuals in the plot without Nephila. Species of Diptera and Coleoptera were captured most frequently. Four saprophagous families, Phoridae and Sciaridae (both Diptera), Staphylinidae and Elateridae (both Coleoptera), were more abundant in the plot with Nephila webs. We show for the first time under natural conditions that prey attraction is most efficient for saprophagous insects, suggesting that the debris-decoration in Nephila webs attracts this guild. We also found that the size of some insects captured does not correspond to the range of prey consumed by Nephila, but to that of kleptobiotic Argyrodes spiders. We hypothesize that the debris-decoration may be used by Nephila as a strategy to limit food competition with Argyrodes.

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Bibliographic Details
Main Authors: Hénaut, Yann Doctor autor 2087, Machkour M'Rabet, Salima Doctora autora 12330, Winterton, Peter autor 15009, Calmé, Sophie Doctora autora 2030
Format: Texto biblioteca
Language:eng
Subjects:Arañas, Nephila clavipes, Trampas para insectos, Artfrosur,
Online Access:http://dx.doi.org/10.1636/T08-72.1
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