Orb-weaving spiders of the Eastern Caribbean
The Eastern Caribbean represents a poorly studied region in terms of arthropod biodiversity, in particular spiders. This paper reviews studies on the biodiversity of orb-weaving spider families on seven islands in the Eastern Caribbean, sampled between January 2006 and August 2010. Specimens were collected using two main methods; visual search and sweep-netting, and supplemented by material collected from the nests of the spider hunting wasp Sceliphron sp. Sampling efforts yielded 33 species distributed among six families. Biodiversity was quantified by examining the observed species richness, diversity indices, species abundance models, and multidimensional scaling plots. Factors such as geographic location and habitat classification were also examined in this study as possible factors influencing orb-weaver biodiversity. No significant difference among the islands was found in terms of species richness, diversity, evenness and dominance. St. Lucia possessed the most distinct orb-weaver species composition, while the faunas of St. Kitts and Nevis and of Grenada and Montserrat were closely associated.