Awareness of global environmental change gives some priority to the study of biodiversity and i ts maintenance (Blandin, 1986; Bridgewater & Walton, 1997). In the evaluation of biodiversity, invertebrates take an important place (New, 1995; Herrenschmidt, 1996; Cranston & Trueman, 1997), and spiders provide an interesting model to represent invertebrates. Numerous authors are aware of the quali...