Behavioral ecology of euglossine bees of the Atlantic rain forest

Before the colonization of Brazil, the Atlantic rain forest extended from Rio Grande do Norte to Rio Grande do Sul. Today, however, the Atlantic forest has been reduced to only 8% of its original size and is highly fragmented. Because of its biological diversity, endemism and number of endangered species, the Atlantic forest is considered to be one of the most threatened habitats in the world. Forest fragmentation can have profound effects on the flora and fauna with the most obvious outcome being a reduction in species diversity. Euglossine bees are the exclusive pollinators of ~ 700 species of orchids in the New World tropics and it is believed that such intricate associations are highly vulnerable to habitat loss. The objective of our study was to compare the abundance and diversity of euglossine bees within a highly fragmented area of the Atlantic forest and test the hypothesis that fragmentation and forest degradation affect species composition. Synthetic compounds resembling orchid fragrances or other natural substances were used to attract male bees. More than 3,600 bees belonging to at least 21 species were collected. Certain species such as Euglossa analis and Eulaema nigrita demonstrated distinct preferences for secondary undisturbed forest and disturbed forest, respectively; however, when all species were considered we found no clear difference in diversity or abundance across nine locations that varied in degree of disturbance. Based on these results, we proposed that the long-established fragments surrounding the Desengano area are functionally interconnected with regard to bee dispersal.