Social wasps are remarkable for their complex social organization, the elaborated architecture of the nests, and for their predatory role in terrestrial alimentary chains controlling populations of other insects and arthropods. Inventories of species in Brazil are still reduced in number as well as the efforts for standardization of collecting protocols, thus inhibiting adequate comparison of results. This work consists in a study of a local fauna of social wasps in a parcel of Amazonian terra firm forest in Caxiuanã, Melgaço, PA. The parcel is a 25 km² square, traversed by two orthogonal sets of 5000m tracks, conferring to the study site a grid format. Collecting methods were “Active search for individual and colonies along 1000m transects” and “Malaise traps installed at transect crosses”. Sixty active search samples and 26 Malaise samples were obtained along a discontinuous period of 44 days. Sixty-five species of 12 genera were collected with both methods. Most species were registered by finding individuals, the spotting of nests being relatively rare events (74 nests). Polybia and Mischocyttarus were the most important genera in species number. Agelaia fulvofasciata and Angiopolybia pallens were the most frequent species. The active search method presented a better performance in species discovery (63) than Malaise trap (26). Two subsets of 25 samples were obtained with DIVA-GIS software, both sets summing to 63 species, thus showing that the all-samples total species number could be obtained with a smaller effort, widely distributed across the area. The survey added 21 species to the list of Caxiuanã, now with a total of 100 species, and produced two new species records for Pará state (Polybia brunnea and Mischocyttarus vaqueroi).
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