Our result indicate that Spider and beetle diversity and composition differ among the three tropical agroecosystem habitats studied-with the details of how they differ particular to each taxon. For instance, beetle diversity was similar across the three habitat types, whereas beetle family composition differed markedly among habitats. In contrast, spider diversity was significantly higher in forest fragments than in edge habitats, and family composition was similar among edge and crop habitats. Although similar studies conducted in mixed agricultural communities in southern Costa Rica have found that beetles(in particular carabids and scarabs) are insensitive to habitat type(Goehring et al. 2002), our findings indicate that at the family level, beetles may be more specialized in their habitat preferences. This may be due to several biotic and abiotic factors, including foraging behavior; Fournier& Loreau (2002) showed that satiated carabid beetles prefer to forage in hedgerows over crop areas, whereas starved beetles prefer crop areas. Beetles from both Curculionidae and Staphylinidae have been documented as being particularly sensitive to habitat fragmentation and disturbance, and hence potentially useful as bioindicators (Bohac 1999, Foord et al. 2003). In our study, Staphylinidae, found commonly in leaf litter, were most prevalent in forest habitats; Curculionidae,