Seasonal variation of Euglossine bees (Apidae: Euglossini) in the North of the Colombian Orinoquia

Euglossine bees are important pollinators of multiple neotropical plant species; however, in many Colombian locations, there is little information about their occurrence. Our objective was to document the change in the richness and abundance of orchid bee species (Apinae: Euglossini) during the dry and rainy seasons in three environments (gallery forest, floodplain, and a path with secondary vegetation) in the department of Arauca, Colombia. Specimens were collected by direct captures using free baits, 32 bottle traps, and four types of bait. The daily intensity of sampling was seven hours (7:00-14:00) for 10 consecutive days in each climatic season. We collected 367 specimens belonging to three genera and 17 species, which represent between 81,1% and 91,9% of the expected species in the study area. The flooded savannah and the path with secondary vegetation were the environments with the highest species richness and abundance compared to the gallery forest. During the rainy season, 16 species were recorded (8 of them exclusive) and nine species (one of them exclusive) in the dry season. There were higher richness and abundance of species during the rainy season. This is the first study of Euglossini bees in savannas of the department of Arauca where our results indicate a diversity comparable to other locations in Colombia and other Neotropical countries.