About 39,882 species of spiders are known to science, belonging to 110 families of 3,676 genera (Platnick, 2007). About 10% of these known species are from America north of Mexico ( Roth, 1993; Schaefer and Kosztarab 1991). Many spider species are not yet known to science, particularly in the tropics. Some arachnologists estimate that only 20% of spider species have been described, meaning that there may be as many as 170,000 spider species sharing our planet with us (Coddington and Levi, 1991). ...