Distribution of species of the genus Bombus Latreille (Hymenoptera, Apidae) in Uruguay

Bumblebees of the genus Bombus Latreille (Hymenoptera: Apidae) play an important role in maintaining natural ecosystems and agricultural production due to their ability as pollinators. Reduction of their populations and the extinction of some species have been verified in some European countries, in the United States, Brazil, Chile and Argentina. In Uruguay five Neotropical species and one exotic species have been reported. However, in the last years only B. pauloensis  and B. bellicosus have been found in the country. The aim of this study was to determine the bumblebee species currently present in Uruguay and their distribution in the country. We analyzed 1126 workers collected between 2009 and 2014 in 73 locations covering the 19 provinces of the country. Observation of the sting capsule of the females was used to identify the species. Of the six species reported for Uruguay, only the presence of B. pauloensis and B. bellicosus was confirmed in this study. The first one presented a wide distribution being present in all the provinces, while B. bellicosus  was registered only in the south of the country. The results found about B. pauloensis and B. bellicosus distributions constitute a base line to monitor in the future the distribution of these species which face several challenges that threaten their populations. This information will be essential to develop appropriate management and protection strategies for these species.