A simple device to collect, store and study samples of two-dimensional spider webs.

Silk production and spinning are the most prominent characteristics of spiders (Araneae). The high diversity of web architectures correlates both with preying behaviors and with the ultra-structure of the silk threads that compose the webs, which in turn have a corresponding diversity of silk gland spigot complements. The details of web construction, thread structure, and gland spigot morphology have proven extremely informative for phylogenetic hypotheses (e.g., Eberhard 1982, 1988; Eberhard & Pereira 1993; Coddington 1989; Griswold et al. 2005; Hormiga et al. 1995; Lopardo & Ramírez 2007; Platnick et al. 1991; Agnarsson & Blackledge 2009; Eberhard 2010), and a fascinating system to study spider diversification and evolutionary trends (e.g., Opell 1996; Opell & Bond 2000; Blackledge et al. 2009, 2012; Dimitrov et al. 2012). The architecture of a spider web can be documented with photographs, for which Carico’s (1977) device made a significant progress, but the sampling of webs has several complexities, especially because of the stickiness of capture threads (Opell 1997), whose structure becomes altered upon the slightest contact. We have tested during several years a very simple device to collect and store two-dimensional web samples, which allows for easy observation using a light or scanning electron microscopy (SEM). Although comparable in concept, our devices are simpler to build than those designed by Opell & Hendrix (2009) and Opell et al. (2011) for single lines, and more importantly, the closed frame we implemented can hold a two-dimensional web without significant distortion. Here we describe this simple device along with some observation and imaging techniques, in the hope that it will promote the documentation of the high diversity of silk structures that are yet to be discovered, and thus facilitate studies that seek establishing a correlation of morphological structures with web building behaviors.