Nesting of the keyhole wasp Pachodynerus nasidens (Latreille, 1812) (Vespidae, Eumeninae) in a nest of a paper wasp (Vespidae, Polistinae)

Potter wasps (Hymenoptera, Vespidae, Eumeninae) adopt different substrates for nesting, including other wasp nests. Nevertheless, such behavior rarely occurs with abandoned nests of the paper wasps (Hymenoptera, Vespidae, Polistinae). In this study, we report the occurrence involving the nesting of a potter wasp on a paper wasp's nest. Such a record occurred in November 2021 in a segment of a deciduous forest, at Mata Seca State Park, Southeast Brazil. An abandoned Polistinae nest was found, with 14 cells sealed with mud, from which four male Pachodynerus nasidens individuals emerged. This record of P. nasidens reusing a Polistinae's nest increases our knowledge of Eumeninae nesting strategies and on possible associations between different groups of vespid wasps.