Social wasps are remarkable for their complex social organization, elaborated architecture of the nests, and predatory activity over other insects and arthropods. The number of inventories made in Brazil has been small as well the efforts for standardization of collecting protocols, so that adequate comparison of results remains difficult. The composition and richness of social wasps in Floresta Nacional de Caxiuanã, Melgaço, PA, Brazil were assessed by performing a structured inventory in a 25 km² square parcel of "terra firme" forest. Collecting methods were "active search for individual and colonies along 1,000 m transects" and "Malaise trapping". Sixty-five species of 12 genera were collected with both methods. Agelaia fulvofasciata (Degeer, 1773) and Angiopolybia pallens (Lepeletier, 1836) were the most frequent species. The active search method performed better (63 spp.) than Malaise traps (26 spp). The survey added 21 species to the list of Caxiuanã, and resulted in a new record for Pará state (Polybia brunnea (Curtis, 1844)).
Polistinae; social wasps; structured inventory; Amazonia
