Long-term comparison of the euglossine community

<p>Global bee decline and its impact on pollination in agricultural and natural ecosystems have attracted public attention. However, more data are needed to show their generality and intensity in different ecosystems, especially in the tropics. For centuries, the tropical dry forest (TDF) of Costa Rica underwent intense deforestation, but in the last four decades, a large part of this forest has entered a recovery process. Using data of orchid bees generated by Janzen et al. (1982) in TDF in the Santa Rosa sector of the Guanacaste Conservation Area (ACG), we posed a general question: What changes have occurred in diversity, composition, and seasonality of the euglossine bee community in the TDF during the last 40 years and how are these changes related to the current recovery of this forest. We sampled euglossine bees during 2018-2019 using methods similar to those applied previously. To characterize the response of euglossine bees to habitat loss, we extended the sampling to pastures adjacent to the protected area. With the loss (n=4) and gain (n=3) of bee species, we did not find significant changes in overall species richness between now and 40 years ago. However, the composition of the euglossine community in the protected area in 1977 was more similar to that found in current pastures than to the current community in forests, where the presence of forest-dependent species has been favored. It is possible that TDF regeneration in Santa Rosa has led to changes in the composition of the community of these bees.</p>