Little is known about the distribution of organisms in transitional areas, overall because of the lack of understanding regarding each species' specificity to the diversity of microhabitats found in these areas and effective ways to sample organisms in these regions. Therefore, in this study we aimed to inventory the bee species in a transitional Cerrado-Amazon area in the state of Pará, Brazil, evaluating the effects of three different sampling methods. We used six fragments, sampled in two

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... ferent seasons with three sampling methods (arboreal pitfalls with urine, scent traps, and pan traps). The specimens were identified and we used accumulation curves to measure the effectiveness of each method. In total, we sampled 68 bee species, where 53 were exclusively from one single sampling method. The pitfall traps were those with reached the highest species richness among all three sampling methods analyzed, followed by the scent traps and pan traps, respectively. Despite the efficiency and generality of the bee groups we found, the pitfall method does not cover specific bee groups as the Euglossini bees, almost exclusively attracted to scent traps. Therefore, we suggest that studies using pitfalls with urine should be performed in other biomes to evaluate the efficiency of this method in future bee surveys.