Long-term ecology of orchid bees in an urban forest remnant

Ecological studies lasting more than 1 or 2 years are not particularly common anywhere and in any taxonomic group. Ecological studies in orchid bees (Hymenoptera: Apidae) are not an exception and have focused on short-term scale. Long-term studies have been mostly neglected up to date. Orchid-bee males were attracted to five different scent baits in the same site every other year during a seven-year span, from 1997 to 2004, in an urban forest remnant, totaling four full years of samplings in between. In total, we captured 2188 bees from 14 species. Species diversity, evenness, and richness remained remarkably stable among years. The stability index, sensu Wolda, for the composite community revealed to be one of the highest ever recorded for insect communities. Our results suggest that orchid-bee populations may remain remarkably stable over the years even in a small (a parts per thousand 200 ha) area immersed in a metropolitan (a parts per thousand 3,000,000 inhabitants) matrix and that these urban areas should not be neglected in conservation efforts, since they seem to maintain viable populations of these important pollinators over time.